Expressão imuno-histoquímica das proteínas E-Caderina e BCL2 e nevos melanociticos orais e cutâneos

Melanocytic nevi (MNs) are benign melanocytic proliferations of cells, which can be found in the skin and mucous coat, including the oral mucosa. However, skin NMs are more common when compared to those that affect the oral mucosa. The molecular mechanisms involved in the development of nevi and the factors that can influence the migration pattern of the nevus cells are little explored. The aim of this study was to analyze the immunohistochemical expression of E-cadherin protein and Bcl-2 in oral / skin NMs and relate them to the clinical characteristics (gender, age, location, exposure to solar radiation) and histopathological types. 36 cases of oral NMs and 34 Skin NMs were analyzed. The immunohistochemistry was used of the protein E-cadherin and bcl-2, which were analyzed the intensity (weak, moderate and strong) and distribution marking (diffuse and focal). The immunoreactivity also analyzed as to the types of nevus cells (epithelioid cells -A, -B lymphocyte and fibroblast-like -C). Statistical analysis was performed using the chi-square tests of Pearson and Spearman correlation with significance level set at 5%. Of the 70 cases of NMs, 82.9% were female, 48.6% aged 26-50 years, 51.4% were diagnosed histologically as intradermal / intramucosal nevi and 80% were NMs acquired. Immunohistochemical expression of BCL2 and E-cadherin were variables in the sample and showed no association with clinical parameters. The expression of bcl-2 and E-cadherin were variable according to the types of nevus cells (A, B and C) (P = 0.001). The expression of bcl-2 was more diffuse in congenital MNs (p = 0.002). E-cadherin was positive in 83.3% of MNs <1cm (p = 0.001) and exhibited weak staining in 73.9% of MNs that were in exposed areas (p = 0.010). Based on these results, it is suggested that the E-cadherin has a modulating effect on the migratory properties of NMs, and bcl-2 is a marker of MNs with increased proliferative capacity.

The association between parental attitudes and alcohol consumption and adolescent alcohol consumption in Southern Ireland: a cross-sectional study

Background: Alcohol plays a complex role in society. A recent study showed that over half of Irish adults drink hazardously. Adolescents report increased levels of alcohol consumption. Previous research has inferred the influence of the parent on their adolescent. Thus, the aim of the current study was to investigate the association between adolescent alcohol consumption and their parent’s consumption pattern and attitude toward alcohol use in Southern Ireland. Methods: A cross-sectional survey was undertaken in November 2014. This involved distributing a survey to adolescents (n = 982) in their final two years of second level education and at least one of their parents from a local electorate area in Southern Ireland. This survey included: alcohol use, self- reported height and weight, smoking status, mental health and well-being along with attitudinal questions. Chi-square tests and multivariate logistic regression were utilised. Results: A 37 % response rate was achieved. Over one-third (34.2 %) of adolescents and 47 % of parents surveyed reported hazardous drinking. Over 90 % of parents disagreed with allowing their adolescent to get drunk and rejected the idea that getting drunk is part of having fun as an adolescent. The majority (79.5 %) of parents surveyed believed that their alcohol consumption pattern set a good example for their adolescent. Multivariate logistic regression highlights the association between adolescent hazardous alcohol consumption and hazardous drinking by the father. Furthermore either parent permitting their adolescent to drink alcohol on special occasions was associated with hazardous alcohol consumption in the adolescent. Conclusion: The findings of this research notes a liberal attitude to alcohol and increased levels of consumption by the parent are linked to hazardous adolescent drinking behaviour. Future action plans aimed at combatting adolescent hazardous alcohol consumption should also be aimed at tackling parents’ attitudes towards and consumption of alcohol.

Implementação da rotina de unfolding para determinação de distribuição de tamanho de grãos esféricos via distribuição de interceptos lineares e de área de seção

Na unfolding method of linear intercept distributions and secction área distribution was implemented for structures with spherical grains. Although the unfolding routine depends on the grain shape, structures with spheroidal grains can also be treated by this routine. Grains of non-spheroidal shape can be treated only as approximation. A software was developed with two parts. The first part calculates the probability matrix. The second part uses this matrix and minimizes the chi-square. The results are presented with any number of size classes as required. The probability matrix was determined by means of the linear intercept and section area distributions created by computer simulation. Using curve fittings the probability matrix for spheres of any sizes could be determined. Two kinds of tests were carried out to prove the efficiency of the Technique. The theoretical tests represent ideal cases. The software was able to exactly find the proposed grain size distribution. In the second test, a structure was simulated in computer and images of its slices were used to produce the corresponding linear intercept the section area distributions. These distributions were then unfolded. This test simulates better reality. The results show deviations from the real size distribution. This deviations are caused by statistic fluctuation. The unfolding of the linear intercept distribution works perfectly, but the unfolding of section area distribution does not work due to a failure in the chi-square minimization. The minimization method uses a matrix inversion routine. The matrix generated by this procedure cannot be inverted. Other minimization method must be used

Association of TNF-α Gene Variants With Clinical Manifestation of Cystic Fibrosis Patients of Iranian Azeri Turkish Ethnicity

Background: Cystic fibrosis (CF), a life-limiting autosomal recessive disorder, is considered a monogenic disease that is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. According to several studies, mutation analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene alone is insufficient to predict the phenotypic manifestations observed in cystic fibrosis (CF) patients. In addition, some patients with a milder CF phenotype do not carry any pathogenic mutation. Tumor Necrosis Factor-alpha (TNF-α) contributes to the pathophysiology of CF by causing cachexia. There is a reverse association between TNF-α concentration in patient's sputum and their pulmonary function. Objectives: To assess the effect of non-CFTR genes on the clinical phenotype of CF, two polymorphic sites (-1031T/C and -308G/A) of the TNF-α gene, as a modifier, were studied. Patients and Methods: Focusing on the lung and gastrointestinal involvement as well as the poor growth, we first investigated the role of TNF-α gene in the clinical manifestation of CF. Furthermore, based on the hypothesis that the cumulative effect of specific alleles of multiple CF modifier genes, such as TNF-α, may create the final phenotype, we also investigated the potential role of TNF-α in non-classic CF patients without a known pathogenic mutation. In all, 80 CF patients and 157 healthy control subjects of Azeri Turkish ethnicity were studied by the PCR–RFLP method. The chi-square test with Yates' correction and Fisher's exact test were used for statistical analysis. Results: The allele and genotype distribution of the investigated polymorphisms, and their associated haplotypes were similar in all groups. Conclusions: There was no evidence that supported the association of TNF-α gene polymorphisms with non-classic CF disease or the clinical presentation of classic CF.

Relationship between menopause and periodontal disease: a cross-sectional study in a Portuguese population

Article published under a “Creative Commons Attribution Noncommercial License”, enabling the unrestricted non-commercial use, distribution, and reproduction of the published article in any medium, provided that the original work is properly cited.

Prevalencia y caracterización de la disfonía, en operadores de un call center en Bogotá Colombia.

Resumen Introducción: El uso de la voz profesional requiere de una técnica y medidas de conservación para no verse afectada. Un inadecuado esquema corporal en el profesional de la voz, ocasiona alteración en los parámetros respiratorios y vocales manifestándose como disfonía. Objetivo: Determinar la prevalencia y caracterización de disfonía en 200 tele operadores de un call Center en Bogotá Colombia. Métodos: Estudio de corte transversal con datos secundarios provenientes de una base de datos con registros de una población de 200 tele operadores de un call center en Bogotá, Colombia, a los cuales se les aplicó evaluación de respiración y de voz durante el año 2003. La estimación de la prevalencia de la disfonía se realizó a través de la distribución de frecuencias relativas. Se realizó caracterización de la población estudiada según variables sociodemográficas, ocupacionales y parámetros respiratorios y vocales a través de métodos estadísticos según la naturaleza de estas variables. Se determinó la asociación entre factores ambientales, síntomas asociados, síntomas vocales, perfil vocal de Wilson y disfonía mediante la prueba de Chi Cuadrado de Pearson. Resultados: la prevalencia de disfonía fue del 73% (n= 146), el 34% presentó grado de disfonía moderado. Los resultados obtenidos en los parámetros de evaluación vocal se encontraron dentro del rango de normalidad, analizados en forma individual (tono, rango intensidad) y se relacionan con los resultados obtenidos con la prevalencia disfonía. El 95,5% de los tele operadores los parámetros respiratorios se encontraron alterados. Los tele operadores con disfonía en comparación a los sin disfonía tuvieron mayor frecuencia de presentación de los siguientes factores ambientales: ruido (68% vs 50,9% p=0,03) y vapores (27,2% vs 11,3% p= 0,02), síntomas corporales y de la voz respectivamente: cuello (69,4% vs 54,7% p= 0,05), dolor en la laringe (19,7% vs 7,5% p= 0,04). Conclusión: La prevalencia de disfonía encontrada en este call center fue alta Lo que requiere la implementación de medidas de prevención como tamizajes acústicos, para hacer seguimiento a las cualidades de la voz más afectadas, entrenamiento respiratorio y vocal, pausas vocales y medidas de conservación de la voz, para contribuir a que el tele operador desarrolle un mejor manejo de sus cualidades vocales acorde con su uso y disminuir la prevalencia de disfonía.

Relación entre las condiciones de higiene y seguridad y la exposición ambiental a solventes orgánicos en pintores de automóviles de la localidad de barrios unidos, Bogotá 2015

Introducción. Los trabajadores de los talleres de reparación de automóviles conviven diariamente con la exposición a los solventes orgánicos, exposición que se convierte en un riesgo para su salud que generalmente en el corto plazo se presenta como déficits de concentración, memoria y tiempo de reacción y en el largo plazo produciendo graves repercusiones clínicas como efectos mutagénicos y carcinogénicos. Objetivo. Caracterizar las condiciones higiénicas y de seguridad de trabajadores ocupacionalmente expuestos a solventes orgánicos y determinar los niveles ambientales de benceno, tolueno y xileno (BTX) en talleres de lámina y pintura automotriz de la ciudad de Bogotá. Materiales y métodos. Se hizo un estudio de corte transversal en 60 trabajadores que laboran expuestos a solventes orgánicos en talleres de reparación automotriz en Bogotá. Se realizó una encuesta con variables sociodemográficas, laborales y se determinaron los niveles en aire de benceno, tolueno y xileno. Para los muestreos ambientales, las bombas se colocaron en una posición fija representativa del ambiente general, con el objeto de conocer la distribución de los solventes en el área de trabajo. Se realizó un análisis descriptivo por conteos de frecuencia, medidas de tendencia central y dispersión. Se utilizó prueba de bondad de ajuste para distribución normal (Kolmogorov-Smirnov o Shapiro Wilk), prueba t Student para comparación de medias, o en su defecto prueba U de Mann Whitney para comparación de medianas. Para identificar la relación entre las características sociodemográficas y ocupacionales con la exposición a BTX, se utilizaron pruebas de asociación Chi cuadrado o análisis de correlación según la naturaleza de las variables. El nivel de significancia para cada prueba fue 0.05. Resultados. La edad promedio de los trabajadores fue de 43 años y un tiempo total de exposición a solventes de 20 años. Respecto al uso de protección corporal, 45 (75%) de los trabajadores manifestaron que usaban uniforme, mientras que 14 (23,3%) usaban ropa de calle durante la jornada laboral. El 46,7% manifestaron usar protección respiratoria. La concentración de benceno en aire fue entre 0,1 y 0,45 mg/l (mediana de 0,31 mg/l; DE 0,13 mg/l); la de tolueno estuvo entre 8,25 y 27,22 mg/l (mediana de 14,5 mg/l; DE 6.99 mg/l) y la de xileno entre 19,34 y 150,15 mg/l (mediana de 70,12 mg/l; DE 40,82 mg/l). Conclusión. Los pintores de automóviles están expuestos a niveles elevados de solventes en los lugares de trabajo y no cuentan con condiciones de higiene y seguridad industrial adecuados. Un gran número de pintores son informales lo que les impide el acceso a los beneficios del Sistema de Seguridad Social Integral.

Prevalencia del desorden músculo-esquelético asociado a la actividad docente en instituciones distritales de la localidad de Usme, Bogotá, D.C.

ANTECEDENTES: Los desórdenes musculo esqueléticos DME son una de las alteraciones más frecuentes y una de las principales causas de ausentismo laboral en el continente americano, y Unión Europea, generando graves repercusiones económicas a nivel empresarial, de la salud pública, y del empleado. Esto es debido a una sobrecarga laboral causada por los trabajos repetitivos, posturas mantenidas, y requerimientos de fuerza muscular, por lo que se hace importante identificarlos a través de distintos métodos ergonómicos con el objeto de generar programas de prevención que permitan la mitigación de los mismos. OBJETIVO: Determinar los síntomas músculo-esqueléticos y su relación con las condiciones de trabajo de los docentes de instituciones educativas distritales de la localidad de Usme, Bogotá, D. C. MATERIALES Y METODOS: Estudio de corte transversal, efectuado en 192 docentes que se evaluaran con el cuestionario Nórdico estandarizado de síntomas musculo esqueléticos y preguntas sociodemográficas de la encuesta de condiciones de trabajo y salud (ECTS) para caracterizar la población estudio. Para el análisis estadístico se realizó distribución de frecuencias y medidas de tendencia central y dispersión. La evaluación de las posibles asociaciones se realizó mediante la prueba de chi-cuadrado de Pearson, con intervalos de confianza del 95%, la prevalencia fue ajustada por género con los intervalos de confianza. RESULTADOS: El 57,8% de los participantes era de sexo femenino, el 41,7% tenían edades entre los 30 y 39 años de edad, el 82,8% de los encuestados manejaban grupos de estudiantes que oscilan entre los 20 a 60 estudiantes, del total de los encuestados el 42,7% (IC95%: 35.9-49.5) presentan un DME ya diagnosticado por un médico o servicio de salud. El 77,1% respondieron afirmativamente a la presencia de esta variable con un IC95%: de 70,3-82,8. En cuanto a la localización del dolor, se observó que la región del cuello con el 51.6% (IC 44.3-58.9) y región lumbar con el 49% (IC95%: 42.2-56.3) fueron las dos regiones anatómicas valoradas con mayor presencia de dolor. Se encontró asociación entre la edad y el dolor (chi-cuadrado: 6,858), el sexo y dolor (chi-cuadrado: 0.250) y el número de estudiantes con el dolor (chi-cuadrado: 2,179) CONCLUSIONES: los resultados obtenidos en el presente estudio confirman la relación existente entre la presencia de desórdenes músculo-esqueléticos (DME) y la actividad docente, pero se hace pertinente la realización de más estudios que permitan valorar los DME con el riesgo psicosocial, jornada laboral y tipo de asignatura que imparten los docentes en sus cátedras para este tipo de población.

The impact of perceived stage of cancer on carers’ anxiety and depression during the patients’ final year of life

Objective: This paper explores the effects of perceived stage of cancer (PSOC) on carers' anxiety and depression during the patients' final year. Methods: A consecutive sample of patients and carers (N=98) were surveyed at regular intervals regarding PSOC, and anxiety and depression using the Hospital Anxiety and Depression Scale. Means were compared by gender using the Mann-Whitney U-test. The chi-square was used to analyse categorical data. Agreement between carers' and patients' PSOC was estimated using kappa statistics. Correlations between carers' PSOC and their anxiety and depression were calculated using the Spearman's rank correlation. Results: Over time, an increasing proportion of carers reported that the cancer was advanced, culminating at 43% near death. Agreement regarding PSOC was fair (kappa=0.29-0.34) until near death (kappa=0.21). Carers' anxiety increased over the year; depression increased in the final 6 months. Females were more anxious (p=0.049, 6 months; p=0.009, 3 months) than males, and more depressed until 1 month to death. The proportion of carers reporting moderate-severe anxiety almost doubled over the year to 27%, with more females in this category at 6 months (p=0.05). Carers with moderate-severe depression increased from 6 to 15% over the year. Increased PSOC was weakly correlated with increased anxiety and depression. Conclusions: Carers' anxiety exceeded depression in severity during advanced cancer. Females generally experienced greater anxiety and depression. Carers were more realistic than patients regarding the ultimate outcome, which was reflected in their declining mental health, particularly near the end.

Characteristics and predictors of high-range speeding offenders

This paper examines an aspect of the data taken from a larger study evaluating the effect of speeding penalty changes on speeding recidivism in Queensland. Traffic offence data from May 1996 to August 2007 were provided to the research team for two cohorts of offenders: individuals who committed a speeding offence in May 2001; and individuals who committed a speeding offence in May 2003. Data included details of the offenders’ index offence, previous and subsequent traffic offences (speeding and other) and their demographic characteristics. Using this data the aim of this component of the research was to use demographic data and the previous traffic offences of these individuals to explore the characteristics and predictors of high-range speeding offenders. High-range offenders were identified as those individuals who committed two or more speeding offences with a recorded speed of 30 km/hr or more above the speed limit. For the purposes of comparison, low-range offenders (committed one speeding offence in the time-frame and that offence was less than 15 km/hr over the speed limit) and mid-range offenders (all other offenders) were identified. Using Chi-square and logistic regression analyses, characteristics and predictors of high-range speeding offenders were identified. The implications and limitations of this study are also discussed.

The relationship of loneliness and social anxiety with children's and adolescents' online communication

Children and adolescents are now using online communication to form and/or maintain relationships with strangers and/or friends. Relationships in real life are important for children and adolescents in identity formation and general development. However, social relationships can be difficult for those who experience feelings of loneliness and social anxiety. The current study aimed to replicate and extend research conducted by Valkenburg and Peter (2007b), by investigating differences in online communication patterns between children and adolescents with and without selfreported loneliness and social anxiety. Six hundred and twenty-six students aged 10-16 years completed a questionnaire survey about the amount of time they engaged in online communication, the topics they discussed, who they communicated with, and their purposes of online communication. Following Valkenburg and Peter (2007b), loneliness was measured with a shortened version of the UCLA Loneliness Scale (Version 3) developed by Russell (1996), whereas social anxiety was assessed with a sub-scale of the Social Anxiety Scale for Adolescents (La Greca & Lopez, 1998). The sample was divided into four groups of children and adolescents: 220 were “non-socially anxious and non-lonely”, 139 were “socially anxious but not lonely”, 107 were “lonely but not socially anxious”, and 159 were “lonely and socially anxious”. A one-way ANOVA and chi-square tests were conducted to evaluate the aforementioned differences between these groups. The results indicated that children and adolescents who reported being lonely used online communication differently from those who did not report being lonely. Essentially, the former communicated online more frequently about personal things and intimate topics, but also to compensate for their weak social skills and to meet new people. Further analyses on gender differences within lonely children and adolescents revealed that boys and girls communicated online more frequently with different partners. It was concluded that for these vulnerable individuals online communication may fulfil needs of self-disclosure, identity exploration, and social interactions. However, future longitudinal studies combining a quantitative with a qualitative approach would better address the relationship between Internet use and psychosocial well-being. The findings also suggested the need for further exploration of how such troubled children and adolescents can use the Internet beneficially.

Patterns of reporting to child protection services in Canada by healthcare and nonhealthcare professionals

Background: All Canadian jurisdictions require certain professionals to report suspected or observed child maltreatment. This study examined the types of maltreatment, level of harm and child functioning issues, controlling for family socioeconomic status, age and gender of the child reported by healthcare and non-healthcare professionals. Methods: We conducted chi-square analyses and logistic regression on a national child welfare sample from the 2003 Canadian Incidence Study of Reported Child Abuse and Neglect (CIS-2003) and compared the differences in professional reporting with its previous cycle (CIS-1998) using Bonferroni-corrected confidence intervals. Results: Our analysis of CIS-2003 data revealed that the majority of substantiated child maltreatment is reported to service agencies by non-healthcare professionals (57%), followed by non-professionals (33%) and healthcare professionals (10%). The number of professional reports increased 2.5 times between CIS-1998 and CIS-2003, while non-professionals’ increased 1.7 times. Of the total investigations, professional reports represented 59% in CIS-1998 and 67% in CIS-2003 (p<0.001). Compared to non-healthcare professionals, healthcare professionals more often reported younger children, children who experienced neglect and emotional maltreatment and those assessed as suffering harm and child functioning issues, but less often exposure to domestic violence. Conclusion: The results indicate that healthcare professionals played an important role in identifying children in need of protection considering harm and other child functioning issues. The authors discuss the reasons why underreporting is likely to remain an issue.

Trends in demographic, health behaviour factors, and self-perceived weight status : influences on obesity in Australia from 1995 to 2005

Overweight and obesity are two of the most important emerging public health issues in our time and regarded by the World Health Organisation [WHO] (1998) as a worldwide epidemic. The prevalence of obesity in the USA is the highest in the world, and Australian obesity rates fall into second place. Currently, about 60% of Australian adults are overweight (BMI „d 25kg/m2). The socio-demographic factors associated with overweight and/or obesity have been well demonstrated, but many of the existing studies only examined these relationships at one point of time, and did not examine whether significant relationships changed over time. Furthermore, only limited previous research has examined the issue of the relationship between perception of weight status and actual weight status, as well as factors that may impact on people¡¦s perception of their body weight status. Aims: The aims of the proposed research are to analyse the discrepancy between perceptions of weight status and actual weight status in Australian adults; to examine if there are trends in perceptions of weight status in adults between 1995 to 2004/5; and to propose a range of health promotion strategies and furth er research that may be useful in managing physical activity, healthy diet, and weight reduction. Hypotheses: Four alternate hypotheses are examined by the research: (1) there are associations between independent variables (e.g. socio -demographic factors, physical activity and dietary habits) and overweight and/or obesity; (2) there are associations between the same independent variables and the perception of overweight; (3) there are associations between the same independent variables and the discrepancy between weight status and perception of weight status; and (4) there are trends in overweight and/or obesity, perception of overweight, and the discrepancy in Australian adults from 1995 to 2004/5. Conceptual Framework and Methods: A conceptual framework is developed that shows the associations identified among socio -demographic factors, physical activity and dietary habits with actual weight status, as well as examining perception of weight status. The three latest National Health Survey data bases (1995 , 2001 and 2004/5) were used as the primary data sources. A total of 74,114 Australian adults aged 20 years and over were recruited from these databases. Descriptive statistics, bivariate analyses (One -Way ANOVA tests, unpaired t-tests and Pearson chi-square tests), and multinomial logistic regression modelling were used to analyse the data. Findings: This research reveals that gender, main language spoken at home, occupation status, household structure, private health insurance status, and exercise are related to the discrepancy between actual weight status and perception of weight status, but only gender and exercise are related to the discrepancy across the three time point s. The current research provides more knowledge about perception of weight status independently. Factors which affect perception of overweight are gender, age, language spoken at home, private health insurance status, and diet ary habits. The study also finds that many factors that impact overweight and/or obesity also have an effect on perception of overweight, such as age, language spoken at home, household structure, and exercise. However, some factors (i.e. private health insurance status and milk consumption) only impact on perception of overweight. Furthermore, factors that are rel ated to people’s overweight are not totally related to people’s underestimation of their body weight status in the study results. Thus, there are unknown factors which can affect people’s underestimation of their body weight status. Conclusions: Health promotion and education activities should provide education about population health education and promotion and education for particular at risk sub -groups. Further research should take the form of a longitudinal study design ed to examine the causal relationship between overweight and/or obesity and underestimation of body weight status, it should also place more attention on the relationships between overweight and/or obesity and dietary habits, with a more comprehensive representation of SES. Moreover, further research that deals with identification of characteristics about perception of weight status, in particular the underestimation of body weight status should be undertaken.

Wandering and the physical environment

Background/Rationale Guided by the need-driven dementia-compromised behavior (NDB) model, this study examined influences of the physical environment on wandering behavior. Methods Using a descriptive, cross-sectional design, 122 wanderers from 28 long-term care (LTC) facilities were videotaped 10 to 12 times; data on wandering, light, sound, temperature and humidity levels, location, ambiance, and crowding were obtained. Associations between environmental variables and wandering were evaluated with chi-square and t tests; the model was evaluated using logistic regression. Results In all, 80% of wandering occurred in the resident’s own room, dayrooms, hallways, or dining rooms. When observed in other residents’ rooms, hallways, shower/baths, or off-unit locations, wanderers were likely (60%-92% of observations) to wander. The data were a good fit to the model overall (LR [logistic regression] χ2 (5) = 50.38, P < .0001) and by wandering type. Conclusions Location, light, sound, proximity of others, and ambiance are associated with wandering and may serve to inform environmental designs and care practices.

On the nature of over-dispersion in motor vehicle crash prediction models

Statistical modeling of traffic crashes has been of interest to researchers for decades. Over the most recent decade many crash models have accounted for extra-variation in crash counts—variation over and above that accounted for by the Poisson density. The extra-variation – or dispersion – is theorized to capture unaccounted for variation in crashes across sites. The majority of studies have assumed fixed dispersion parameters in over-dispersed crash models—tantamount to assuming that unaccounted for variation is proportional to the expected crash count. Miaou and Lord [Miaou, S.P., Lord, D., 2003. Modeling traffic crash-flow relationships for intersections: dispersion parameter, functional form, and Bayes versus empirical Bayes methods. Transport. Res. Rec. 1840, 31–40] challenged the fixed dispersion parameter assumption, and examined various dispersion parameter relationships when modeling urban signalized intersection accidents in Toronto. They suggested that further work is needed to determine the appropriateness of the findings for rural as well as other intersection types, to corroborate their findings, and to explore alternative dispersion functions. This study builds upon the work of Miaou and Lord, with exploration of additional dispersion functions, the use of an independent data set, and presents an opportunity to corroborate their findings. Data from Georgia are used in this study. A Bayesian modeling approach with non-informative priors is adopted, using sampling-based estimation via Markov Chain Monte Carlo (MCMC) and the Gibbs sampler. A total of eight model specifications were developed; four of them employed traffic flows as explanatory factors in mean structure while the remainder of them included geometric factors in addition to major and minor road traffic flows. The models were compared and contrasted using the significance of coefficients, standard deviance, chi-square goodness-of-fit, and deviance information criteria (DIC) statistics. The findings indicate that the modeling of the dispersion parameter, which essentially explains the extra-variance structure, depends greatly on how the mean structure is modeled. In the presence of a well-defined mean function, the extra-variance structure generally becomes insignificant, i.e. the variance structure is a simple function of the mean. It appears that extra-variation is a function of covariates when the mean structure (expected crash count) is poorly specified and suffers from omitted variables. In contrast, when sufficient explanatory variables are used to model the mean (expected crash count), extra-Poisson variation is not significantly related to these variables. If these results are generalizable, they suggest that model specification may be improved by testing extra-variation functions for significance. They also suggest that known influences of expected crash counts are likely to be different than factors that might help to explain unaccounted for variation in crashes across sites