RESUMO
Despite the importance of locust density-dependent polyphenism as a model system for understanding phenotypic plasticity, there is still much to be learnt about its underlying molecular control. Here we describe the first investigation into the expression of genes encoding the DNA methylation machinery in the migratory locust (Locusta migratoria). We show that the alternative solitarious and gregarious phenotypic states induced by different locust rearing densities are associated with significant differences in the expression of the target genes DNA methyltransferase 1, DNA methyltransferase 2 and methyl-CpG-binding domain protein 2/3. This variation was most pronounced in the embryos of solitarious vs. gregarious mothers. We mapped the embryonic methylation profiles of several intragenic regions and a Long Interspersed Nuclear Element (LINE), each of which is known to be differentially expressed between alternative locust phenotypes or has been directly implicated in phase change. LmI and three genes, adenyl cyclase-associated binding protein 2, choline kinase alpha-like and henna, were methylated. Our results set the stage for future studies investigating the specific role of DNA methylation in the maternal transfer of migratory locust phase polyphenism.
Assuntos
Proteínas Arqueais/genética , Metilação de DNA/genética , Locusta migratoria/genética , Metiltransferases/genética , Animais , Colina Quinase/genética , Regulação da Expressão Gênica , Elementos Nucleotídeos Longos e Dispersos/genética , FenótipoRESUMO
Tropical cyclones can highly modify coastal ecosystems through interactions between their unique set of meteorological traits and an ecosystem's antecedent conditions. As such, resultant changes to biological community structure are likely storm-specific, yet our understanding of cyclone effects on marine communities is limited compared to communities in terrestrial and freshwater habitats. Using northwestern Gulf of Mexico (NWGOM) mesozooplankton data, we tested: (1) for differences between storm and non-storm community structure and dispersion; (2) if post-storm communities varied between one another; (3) if salinity drove differences; and (4) if physical drivers of abundance and evenness varied between storm and non-storm communities. Mesozooplankton community structure following Hurricanes Harvey, Ike, Rita, and during five non-storm years were analyzed. Post-Ike, post-Rita, and non-storm communities were similar while post-Harvey communities were distinct from non-storm years. A structural equation model revealed stratification and abundance drove community evenness. Post-Harvey mesozooplankton were more abundant in low salinity waters; a pattern muted during non-storm years. NWGOM mesozooplankton community structure was generally resilient to hurricane effects, except when large changes in salinity occurred. Our findings suggest resource availability for planktivorous predators and energy transfer within coastal food webs is altered following cyclones with high precipitation rates.
Assuntos
Tempestades Ciclônicas , Animais , Ecossistema , Cadeia Alimentar , Golfo do México , ZooplânctonRESUMO
Programmed death ligand 1 (PD-L1) expression in antigen-presenting cells and tumors can inhibit T cell-mediated immunity. In this study, PD-L1 mRNA and protein expression was evaluated in canine B cell lymphoma (CLL17-71), large T-cell leukemia (CLGL-90), B cell leukemia (GL-1) and primitive leukocyte round cell neoplasia (CLL-1390). Variable PD-L1 mRNA and protein were observed in these cells with high endogenous expression present in CLL17-71 cells. PD-L1 protein was also observed in canine patient B cell lymphoma tissues using immunostaining. PD-L1 and signal transducer and activator of transcription 1 ( STAT1 ) mRNA expression were reduced in the presence of mitogen-activated protein kinase kinase 1.2 (MEK1/2) inhibitors RDEA119 and AZD6244 in CLL 17-71 cells. RDEA119 had similar effect on PD-L1 and STAT-1 in IFN-γ activated CLL-1390 cells. Overall, these results indicate that PD-L1 is expressed in canine B cell lymphoma. Its inhibition by MEK1/2 inhibitors suggests a possible treatment strategy using targeted drugs which likely could enhance antitumor immune response.
Assuntos
Benzimidazóis/farmacologia , Difenilamina/análogos & derivados , Doenças do Cão/metabolismo , Linfoma de Células B/veterinária , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Sulfonamidas/farmacologia , Animais , Linhagem Celular Tumoral , Difenilamina/farmacologia , Cães , Regulação para Baixo , Citometria de Fluxo/veterinária , Immunoblotting/veterinária , Linfoma de Células B/metabolismo , Reação em Cadeia da Polimerase/veterináriaRESUMO
INTRODUCTION: Solving complex problems such as preventing chronic diseases introduces unique challenges for the creation and application of knowledge, or knowledge to action (KTA). KTA approaches that apply principles of systems thinking are thought to hold promise, but practical strategies for their application are not well understood. In this paper we report the results of a scan of systems approaches to KTA with a goal to identify how to optimize their implementation and impact. METHODS: A 5-person advisory group purposefully selected 9 initiatives to achieve diversity on issues addressed and organizational forms. Information on each case was gathered from documents and through telephone interviews with primary contacts within each organization. Following verification of case descriptions, an inductive analysis was conducted within and across cases. RESULTS: The cases revealed 5 guidelines for moving from conceiving KTA systems to implementing them: (1) establish and nurture relationships, (2) co-produce and curate knowledge, (3) create feedback loops, (4) frame as systems interventions rather than projects, and (5) consider variations across time and place. CONCLUSION: Results from the environmental scan are a modest start to translating systems concepts for KTA into practice. Use of the strategies revealed in the scan may improve KTA for solving complex public health problems. The strategies themselves will benefit from the development of a science that aims to understand adaptation and ongoing learning from policy and practice interventions, strengthens enduring relationships, and fills system gaps in addition to evidence gaps. Systems approaches to KTA will also benefit from robust evaluations.
TITRE: Passer de la connaissance à l'action pour résoudre des problèmes complexes : aperçu de l'examen de neuf cas internationaux. INTRODUCTION: La résolution de problèmes complexes du type de la prévention des maladies chroniques présente des défis particuliers pour la création et le transfert de connaissances, soit le passage de la connaissance à l'action (PCA). Les approches axées sur le PCA respectant les principes de la pensée systémique sont jugées prometteuses, mais les stratégies pour les mettre en place ne sont pas bien comprises. Dans cet article, nous présentons les résultats d'une analyse de plusieurs approches systémiques axées sur le PCA dans le but de déterminer comment optimiser leur mise en oeuvre et leur efficacité. MÉTHODOLOGIE: Un groupe consultatif de cinq personnes a choisi neuf initiatives représentant une diversité d'enjeux et de formes organisationnelles. Pour chaque cas, l'information a été recueillie à partir de documents et par l'entremise d'entrevues téléphoniques avec des personnes-ressources de chaque organisation. Après la vérification des descriptions de cas, une analyse inductive a été effectuée à la fois pour chaque cas et entre les cas. RÉSULTATS: Ces cas ont révélé cinq lignes directrices permettant de passer de la conception de systèmes de PCA à leur mise en oeuvre : 1) établir et entretenir des relations, 2) coproduire et organiser les connaissances, 3) créer des boucles de rétroaction, 4) les encadrer comme des interventions systémiques plutôt que comme des projets et 5) envisager des variations dans le temps et selon les lieux. CONCLUSION: Les résultats de cette analyse contextuelle constituent un départ modeste pour transformer en résultats concrets les concepts systémiques de PCA. L'utilisation des stratégies mises au jour pourrait améliorer le PCA pour la résolution de problèmes complexes en matière de santé publique. Les stratégies elles-mêmes pourront bénéficier de l'évolution d'une science visant à comprendre l'adaptation et l'apprentissage constant des politiques et des interventions pratiques, ce qui renforcera les relations durables et comblera les lacunes des systèmes, et pas simplement celles des données probantes. Les approches systémiques de PCA tireront également des bénéfices d'évaluations rigoureuses.
Assuntos
Conhecimento , Resolução de Problemas , Desenvolvimento de Programas/métodos , Saúde Pública , Análise de Sistemas , Retroalimentação , Humanos , Comunicação Interdisciplinar , Relações Interprofissionais , Integração de SistemasRESUMO
AIMS: To update the analysis of the cohort mortality and cancer incidence study of employees in the Australian petroleum industry. METHODS: Employees from 1981 to 1996 were traced through the Australian National Death Index and the National Cancer Statistics Clearing House. Cause specific mortality and cancer incidence were compared with those of the Australian population by means of standardised mortality ratios (SMRs) and standardised incidence ratios (SIRs). Associations between increased incidence of specific cancers and employment in the petroleum industry were tested by trends according to period of first employment, duration of employment, latency, and hydrocarbon exposure, adjusting for personal smoking history where appropriate. Total follow up time was 176 598 person-years for males and 10 253 person-years for females. RESULTS: A total of 692 of the 15 957 male subjects, and 16 of the 1206 female subjects had died by the cut off date, 31 December 1996. In males, the all-cause SMR and the SMRs for all major disease categories were significantly below unity. There was a non-significant increase of the all-cancer SIR (1.04, 95% CI 0.97 to 1.11). There was a significant increase of the incidence of melanoma (SIR 1.54, 95% CI 1.30 to 1.81), bladder cancer (SIR 1.37, 95% CI 1.00 to 1.83), and prostate cancer (SIR 1.19, 95% CI 1.00 to 1.40), and a marginally significant excess of pleural mesothelioma (SIR 1.80, 95% CI 0.90 to 3.22), leukaemia (SIR 1.39, 95%CI 0.91 to 2.02), and multiple myeloma (SIR 1.72, 95% CI 0.96 to 2.84). CONCLUSIONS: Most cases of mesothelioma are probably related to past exposure to asbestos in refineries. The melanoma excess may be the result of early diagnosis. The excess bladder cancer has not been observed previously in this industry and is not readily explained. The divergence between cancer incidence and cancer mortality suggests that the "healthy worker effect" may be related to early reporting of curable cancers, leading to increased likelihood of cure and prolonged mean survival time.
Assuntos
Causas de Morte , Indústrias Extrativas e de Processamento , Neoplasias/epidemiologia , Doenças Profissionais/epidemiologia , Petróleo , Austrália/epidemiologia , Intervalos de Confiança , Feminino , Humanos , Incidência , Masculino , Mesotelioma/epidemiologia , Mesotelioma/etiologia , Neoplasias/etiologia , Neoplasias/mortalidade , Doenças Profissionais/etiologia , Doenças Profissionais/mortalidade , Estudos Prospectivos , Neoplasias da Bexiga Urinária/epidemiologia , Neoplasias da Bexiga Urinária/etiologiaRESUMO
Researchers explored factors related to sixth graders' sexual behavior. First, level of sexual behavior and sexual behavior intentions were examined. Second, health-related risk behaviors and constructs from Social Support and Social Cognitive theories were analyzed based on race and gender to determine their predictive value for sixth graders engaging in sexual intercourse. Findings indicated that very few sixth graders engaged in sexual intercourse or in high-risk behaviors such as smoking. Of the risk factors examined, smoking was the highest predictor of engaging in sexual intercourse for all categories of race and gender. Of the constructs, Efficacy Expectations consistently predicted engaging in sexual intercourse for all race and gender categories.
PIP: This study explored factors related to the sexual behavior of sixth graders with an emphasis on the level of sexual behavior and its intentions, and the health-related risk behaviors. Furthermore, analyzed the Social Support and Social Cognitive theories based on race and gender in relation to their predictive value in engaging sexual intercourse. A sample of 683 students from 13 elementary schools in an urban, midwestern county were given questionnaires, which consisted of background information, items that represented theoretical constructs, and items that assessed the risk factors. Results revealed that very few sixth graders (7%) had engaged in sexual intercourse, while 8% intended to engage in sexual intercourse before finishing high school and 22% after finishing high school. Of the risk factors examined, smoking was the highest predictor of engaging in sexual intercourse for all categories of race and gender. Other risk factors given include alcohol use, having a steady boyfriend/girlfriend, and engaging in hazardous practices, as well as educational expectations. Prediction of sexual behaviors using theoretical constructs manifest that Social Support for not engaging in sexual intercourse is highly correlated with sexual behavior when tested by gender and for non-Whites. This study also shows that Efficacy Expectations consistently predict sexual intercourse across all races and gender categories.
Assuntos
Comportamento Infantil , Coito/psicologia , Atitude Frente a Saúde , Criança , Comportamento Infantil/etnologia , Comportamento Infantil/psicologia , Feminino , Humanos , Modelos Logísticos , Masculino , Assunção de Riscos , Fatores Sexuais , Fumar/psicologia , Inquéritos e QuestionáriosRESUMO
A sample consisting of 689 junior high school rural adolescents was surveyed about their perceptions of being a teen parent and their current sexual behavior. A risk factor analysis also was conducted to determine factors that significantly predict whether adolescents had engaged in sexual intercourse. Results indicate that one in nine adolescents had engaged in sexual intercourse (11%). The risk factor analyses showed that smoking and efficacy expectations of not engaging in sexual intercourse were significant predictors for both genders. For the most part, adolescents responded positively on four constructs: 1) attitudes toward being a teen parent; 2) efficacy expectations of not engaging in sexual intercourse; 3) benefits of being a teen parent; and 4) and barriers to being a teen parent. However, when analyses were conducted for males and females separately, females scored higher on each factor. Overall, results indicate these teens recognized problems that may occur from being a teen parent.
PIP: 689 rural junior high school students in 2 counties of northwest Ohio were surveyed in fall 1996 about their perceptions of being a teen parent and their current sexual behavior. The authors also investigated which factors significantly predict whether adolescents had engaged in sexual intercourse. Most respondents were aged 13 and 14 years, 51% were male, 92% were White and 5% were Hispanic, and 80% reported paying full price for their school lunch. 11% of the adolescents had ever had sexual intercourse. 81% reported being certain that they would use contraception if they had intercourse, and 93% believed that their parents would disapprove of them being a teen parent. Factor analyses showed that smoking and efficacy expectations of not having sexual intercourse were significant predictors of having intercourse for both sexes. For the most part, the adolescents responded positively on the following constructs: attitudes toward being a teen parent, efficacy expectations of not having sexual intercourse, the benefits of being a teen parent, and barriers to being a teen parent. However, when analyses were conducted for males and females separately, females scored higher on each factor. Study results indicate that these teens recognized problems which may occur from being a teen parent.
Assuntos
Atitude Frente a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Poder Familiar , Gravidez na Adolescência , Saúde da População Rural , Estudantes/psicologia , Adolescente , Análise Fatorial , Feminino , Humanos , Masculino , Ohio , Valor Preditivo dos Testes , Gravidez , Gravidez na Adolescência/estatística & dados numéricos , Fatores de Risco , Comportamento Sexual , Fumar/psicologia , Inquéritos e QuestionáriosRESUMO
The purpose of this investigation was to evaluate velopharyngeal adequacy in gerontologic subjects using an acoustic analysis strategy. Sixty normal older subjects (30 male, 30 female), ranging in age from 50 to 80, read three passages developed by Fletcher (1976) that differ in number of nasal sounds. In addition, all subjects sustained the vowel /a/. The speech samples were analyzed using TONAR II, which calculates the ratio of nasal sound pressure level to nasal + oral sound pressure level (nasalance). Tonagrams (plots of nasalance over time) were obtained from all subjects. Results demonstrated that older subjects generally evidenced abnormally high nasalance values for the Zoo Passage (contains no nasal sounds). In addition, females exhibited significantly higher nasalance values than males. Inspection of the tonagrams revealed three abnormal acoustic patterns: (1) pervasively high nasalance, (2) momentary loss of velar control, (3) progressive deterioration in velar control. These results are discussed with reference to known neuroanatomical changes associated with advancing age.
Assuntos
Idoso , Qualidade da Voz , Voz , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Faringe/fisiologia , Fatores SexuaisRESUMO
To better prepare new graduates for entry-level positions in community settings, faculty of one college of nursing gathered information using focus groups of prospective employers. The groups were to identify the skills and qualities nurses need to practice in the community and ways to redesign nursing curricula to better prepare undergraduates for community-based practice. Data for this qualitative study were collected in five separate focus groups conducted with prospective employers (N = 18) from four major areas of Kentucky. By collaborating with prospective employers in the community, a partnership was established between nurse educators and community health leaders to improve the marketability of baccalaureate graduates. Assessment was the most frequently named skill essential to nursing practice in the community. Independence, critical thinking, collaboration, and confidence consistently emerged as important skills and qualities. Prospective employers were positive about developing partnerships to improve under-graduate nursing curricula. Recommendations for curricula to better prepare undergraduates for community-based practice are suggested.
Assuntos
Enfermagem em Saúde Comunitária , Currículo , Bacharelado em Enfermagem , Docentes de Enfermagem , Emprego , Grupos Focais , Humanos , KentuckyRESUMO
Electromyographic information was obtained from seven right shoulder complex muscles in nine subjects (three normal, three paraplegic, and three quadriplegic) during the occupational therapy activity of bilateral sanding on an incline board, an activity that has been recommended as a treatment modality to strengthen the triceps brachii. Electromyography revealed that the anterior and middle portions of the deltoid were the muscles most responsible for the subjects' arm movements during both resisted and unresisted bilateral sanding . Triceps lateralis and medialis were also active during the up phase, but not as consistently as the deltoid. Pectoralis major and biceps brachii were not extensively active in most subjects. The small size and heterogeneity of the subject sample limits the generalizations of our findings. However, graded resisted bilateral sanding does appear to be an appropriate activity for strengthening the shoulder muscle group, especially the deltoid and triceps brachii, in the tested patient populations.
Assuntos
Músculos/fisiopatologia , Terapia Ocupacional , Ombro/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Eletromiografia , Humanos , Paraplegia/fisiopatologia , Quadriplegia/fisiopatologiaRESUMO
The validity of self-reported health behaviors using monothematic questionnaires has been questioned as such use may enhance subjects' response set. Subsequently, 367 students in a midwestern university were randomly assigned to one of two questionnaire groups, monothematic or nonmonothematic. No significant differences were observed between the two groups on total reported alcohol consumption.
Assuntos
Consumo de Bebidas Alcoólicas , Humanos , Distribuição Aleatória , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
Faculty and chairpersons (N = 102) at 34 programs granting doctoral degrees in health education were asked to rate the quality of professional journals related to health education. The American Journal of Public Health was the highest rated journal. Health Education Quarterly was second, and Health Education Research, the only other health education journal, was rated in the top 10 (rated 7). The journals from the epidemiology area rated higher than journals from other areas. The respondents were least familiar with journals on the environment, safety, and death education.
Assuntos
Atitude , Educação em Saúde , Publicações Periódicas como Assunto/normas , Editoração/normas , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e QuestionáriosRESUMO
The effect of varying both the solution pH and copolymer concentration on the structure of layers of poly[2-(methacryloyloxy)ethyl phosphorylcholine-block-2-(dimethylamino)ethyl methacrylate] copolymer (denoted as MPC(30)-DMA(60), M(n) = 18,000) adsorbed at the air/water interface is studied using surface tension and specular neutron reflection. The surface structure of the adsorbed diblock copolymer is represented by a dense layer of 10-15 A on the air side, accompanied by a loose layer of 20-30 A extending into the aqueous phase. Although the uniform layer model generally provided a reasonable description of the adsorbed copolymer chains, some deviations were observed. A more detailed analysis showed that the distribution of the copolymer across the interface required a minimum of three layers to take into account the structural inhomogeneities. Refinement of the structural distributions involved the combined fitting of partially deuterated copolymer in null reflecting water and D(2)O and the fully hydrogenated copolymer in D(2)O, leading to a substantial improvement in the reliability of the structural profiles obtained. The data analysis showed an increase in surface excess at higher copolymer concentrations and at more alkaline pH. However, the copolymer layer was fully immersed in water under all conditions studied. Because the surface excess showed a steady increase across the cmc over the high pH range, we speculate that copolymer adsorption above the cmc involves the formation of surface micellar aggregates under these conditions.
Assuntos
Materiais Biocompatíveis/química , Membranas Artificiais , Metacrilatos , Nêutrons , Transição de Fase , Fosforilcolina , Adsorção , Óxido de Deutério/química , Concentração de Íons de Hidrogênio , Tensão SuperficialRESUMO
There has been a recent shift in public health policy towards population-based approaches to the reduction of cardiovascular disease. This shift has been accompanied by a re-examination of strategies appropriate to the goal. Often, community development approaches, designed to affect socio-environmental change, are suggested as the most appropriate strategy for affecting community-wide change. Despite the fact that community development approaches have been used by several of the major community-based heart health initiatives, evidence of their use and usefulness remains sparse. This paper presents the findings of a qualitative study of the factors (i.e. community context, facilitators, barriers) affecting the use of community development approaches to heart health promotion in Ontario, Canada. Key informant interviews (n = 30) were conducted with stake-holders representing voluntary agencies, community health providers, boards of education and local coalitions in eight of the 42 health unit areas across Ontario. The qualitative analysis reveals (1) that the use of comprehensive community development approaches is limited and (2) that community agencies typically employ elements of community development approaches (e.g. community organization, community-based), often in combination and adapted to suit local conditions. The resulting landscape of community development approaches is characterized by a continuum of collaborative practices indicating that no one type of community approach is appropriate for all initiatives and in all communities. Therefore, from a programmatic perspective, it may not be realistic to advocate community development as the goal to which all communities should strive.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Participação da Comunidade/métodos , Promoção da Saúde/métodos , Atitude Frente a Saúde , Indicadores Básicos de Saúde , Humanos , OntárioRESUMO
There are many challenging problems related to bleeding and anticoagulation in cardiac surgery. Practical guidelines, which are based on available evidence, can help to direct management issues of post-bypass bleeding, perioperative anticoagulation and the use of haemostatic agents. The patient's bleeding history is the most useful preoperative screening test of haemostasis. The input of a haematologist is often valuable in a number of areas, such as preoperative assessment of patients with a significant history of bleeding, or past history of heparin-induced thrombocytopenia, a lupus anticoagulant, or recent venous thromboembolism. Cardiothoracic surgeons, anaesthetists, perfusionists and haematologists can ensure 'best practice' by being actively involved in the development of 'local' transfusion and anticoagulation guidelines, hospital transfusion committee policies, and audits.
RESUMO
The relative contributions of intramuscular and extramuscular receptors to changes in the reflex excitability of soleus motoneurons, following muscle stretch, have been studied in man. It was found that reflex excitability was decreased by muscle stretch. The extent of the decrease was related to the amount of stretch, irrespective of whether the latter was produced by dorsiflexion of the ankle or by depression of the Achilles tendon with the ankle joint fixed. The results were unaffected by anaesthesia of the skin. It would appear that neither joint receptors nor cutaneous mechanoreceptors contribute significantly to the decrease in reflex excitability during ankle dorsiflexion and that the intramuscular receptors are mainly responsible for the effects observed.
Assuntos
Mecanorreceptores/fisiologia , Neurônios Motores/fisiologia , Músculos/inervação , Reflexo de Estiramento , Adulto , Articulação do Tornozelo/inervação , Feminino , Reflexo H , Humanos , Perna (Membro)/inervação , Masculino , Contração Muscular , Fusos Musculares/fisiologia , Pele/inervaçãoRESUMO
H-reflex recovery curves have been elicited by subliminal conditioning stimuli applied to the ipsilateral and contralateral posterior tibial nerves in 10 healthy female subjects. In both types of recovery curve there was clear evidence of a period of facilitation in the ipsilateral soleus motoneuron pool 75-250 msec after the conditioning stimulus. These results indicate the bilateral nature of the facilitation and show it to be most probably produced by stimulus-evoked inputs as opposed to twitch-evoked inputs. If the facilitation is produced by descending long-loop reflex influences, then complementary evidence is provided for previous electromyographic data showing the bilaterality of long-loop reflexes evoked by percutaneous electrical stimulation. It is impossible, however, at the present time, to rule out the possible involvement of cutaneous afferent discharges or other stimulus evoked inputs in the late facilitation.
Assuntos
Reflexo H , Neurônios Motores/fisiologia , Reflexo Monosináptico , Adulto , Dominância Cerebral , Estimulação Elétrica , Feminino , Humanos , Perna (Membro) , Nervo Tibial/fisiologiaRESUMO
A procedure for modeling H-reflex recovery curve data is described. The procedure involves fitting a cubic spline function to the recorded data points in such a way that the goodness of fit is determined by the standard error of the mean of each point. The cubic spline function possesses numerous advantages over other subjective and objective procedures for extracting information from the excitability curve.
Assuntos
Reflexo H , Reflexo Monosináptico , MatemáticaRESUMO
AIM OF STUDY: Assess the value of computed tomography (CT) in the evaluation of abnormalities in the cochlea and auditory pathways. MATERIAL AND METHODS: We used CT to evaluate 108 children before cochlear implantation surgery. Children's ages at implantation ranged from 21 months to 16 years (mean age, 5.4 years). The etiology of deafness was meningitis in 44 children (40.8%), congenital in 51 (47.2%), and other in 13 children (12%). RESULTS: Eighteen of the 108 (16.6%) children and 34% of the postmeningitic children were found to have at least partial obliteration of the cochlea. Two (2%) children had congenital malformations of the cochlea and 12 children (11.1%) had abnormalities in the brain CT-scan. CT diagnostic values in postmeningitic children regarding cochlear obliteration were accuracy, 75%; sensitivity, 62%; specificity, 82%; positive predictive value, 66.6%; and negative predictive value, 79.3%. In six (20.6%) of postmeningitic children with normal CT-scans, some scala tympani drillout was required. CONCLUSION: CT-scan is capable neither of predicting with certainty the presence of minor degrees of cochlear obliteration nor of specifically imaging either the auditory nerve or its central connections.