Genetic and environmental influences on structural brain measures in twins with autism spectrum disorder.

Atypical growth patterns of the brain have been previously reported in autism spectrum disorder (ASD) but these alterations are heterogeneous across individuals, which may be associated with the variable effects of genetic and environmental influences on brain development. Monozygotic (MZ) and dizygotic (DZ) twin pairs with and without ASD (aged 6-15 years) were recruited to participate in this study. T1-weighted MRIs (n = 164) were processed with FreeSurfer to evaluate structural brain measures. Intra-class correlations were examined within twin pairs and compared across diagnostic groups. ACE modeling was also completed. Structural brain measures, including cerebral and cerebellar gray matter (GM) and white matter (WM) volume, surface area, and cortical thickness, were primarily influenced by genetic factors in TD twins; however, mean curvature appeared to be primarily influenced by environmental factors. Similarly, genetic factors accounted for the majority of variation in brain size in twins with ASD, potentially to a larger extent regarding curvature and subcortical GM; however, there were also more environmental contributions in twins with ASD on some structural brain measures, such that cortical thickness and cerebellar WM volume were primarily influenced by environmental factors. These findings indicate potential neurobiological outcomes of the genetic and environmental risk factors that have been previously associated with ASD and, although preliminary, may help account for some of the previously outlined neurobiological heterogeneity across affected individuals. This is especially relevant regarding the role of genetic and environmental factors in the development of ASD, in which certain brain structures may be more sensitive to specific influences.

Genetic and Environmental Influences on Lobar Brain Structures in Twins With Autism.

This investigation examined whether the variation of cerebral structure is associated with genetic or environmental factors in children with autism spectrum disorder (ASD) compared with typically developing (TD) controls. T1-weighted magnetic resonance imaging scans were obtained from twin pairs (aged 6-15 years) in which at least one twin was diagnosed with ASD or both were TD. Good quality data were available from 30 ASD, 18 discordant, and 34 TD pairs (n = 164). Structural measures (volume, cortical thickness, and surface area) were generated with FreeSurfer, and ACE modeling was completed. Lobar structures were primarily genetically mediated in TD twins (a2 = 0.60-0.89), except thickness of the temporal (a2 = 0.33 [0.04, 0.63]) and occipital lobes (c2 = 0.61 [0.45, 0.77]). Lobar structures were also predominantly genetically mediated in twins with ASD (a2 = 0.70-1.00); however, thickness of the frontal (c2 = 0.81 [0.71, 0.92]), temporal (c2 = 0.77 [0.60, 0.93]), and parietal lobes (c2 = 0.87 [0.77, 0.97]), and frontal gray matter (GM) volume (c2 = 0.79 [0.63, 0.95]), were associated with environmental factors. Conversely, occipital thickness (a2 = 0.93 [0.75, 1.11]) did not exhibit the environmental contributions that were found in controls. Differences in GM volume were associated with social communication impairments for the frontal (r = 0.52 [0.18, 0.75]), temporal (r = 0.61 [0.30, 0.80]), and parietal lobes (r = 0.53 [0.19, 0.76]). To our knowledge, this is the first investigation to suggest that environmental factors influence GM to a larger extent in children with ASD, especially in the frontal lobe.

Differences in Cortical Structure and Functional MRI Connectivity in High Functioning Autism.

Autism spectrum disorders (ASD) represent a complex group of neurodevelopmental conditions characterized by deficits in communication and social behaviors. We examined the functional connectivity (FC) of the default mode network (DMN) and its relation to multimodal morphometry to investigate superregional, system-level alterations in a group of 22 adolescents and young adults with high-functioning autism compared to age-, and intelligence quotient-matched 29 healthy controls. The main findings were that ASD patients had gray matter (GM) reduction, decreased cortical thickness and larger cortical surface areas in several brain regions, including the cingulate, temporal lobes, and amygdala, as well as increased gyrification in regions associated with encoding visual memories and areas of the sensorimotor component of the DMN, more pronounced in the left hemisphere. Moreover, patients with ASD had decreased connectivity between the posterior cingulate cortex, and areas of the executive control component of the DMN and increased FC between the anteromedial prefrontal cortex and areas of the sensorimotor component of the DMN. Reduced cortical thickness in the right inferior frontal lobe correlated with higher social impairment according to the scores of the Autism Diagnostic Interview-Revised (ADI-R). Reduced cortical thickness in left frontal regions, as well as an increased cortical thickness in the right temporal pole and posterior cingulate, were associated with worse scores on the communication domain of the ADI-R. We found no association between scores on the restrictive and repetitive behaviors domain of ADI-R with structural measures or FC. The combination of these structural and connectivity abnormalities may help to explain some of the core behaviors in high-functioning ASD and need to be investigated further.

Effects of the type and thickness of ceramic, substrate, and cement on the optical color of a lithium disilicate ceramic.

STATEMENT OF PROBLEM: Reproducing the characteristics of natural teeth in ceramic crowns remains a complex and difficult process. PURPOSE: The purpose of this in vitro study was to evaluate the effect of the substrate, cement, type, and thickness of the ceramic on the resulting color of a lithium disilicate ceramic. MATERIAL AND METHODS: Forty ceramic disks were prepared from IPS e.max Press LT (low translucency) and HO (high opacity) in 2 different thicknesses (1.5 and 2 mm). The LT groups were composed of monolithic ceramic disks, and the HO groups were composed of disks fabricated with a 0.5-mm thickness combined with a 1- or 1.5-mm veneering ceramic thickness. Disks made of composite resin (R) and alloy (A) were used as substrate structures. The resin cement used was Variolink II. Color was measured with a spectrophotometer and expressed in CIELAB coordinates. Color differences (ΔE) were calculated. The data were analyzed with ANOVA and the Tukey HSD test (α=.05). RESULTS: When the ΔE of ceramic disks with both substrates, with and without cement, were compared, the lowest value (3) was obtained for ceramic HO with a 2-mm thickness/alloy substrate/without cement; the highest value (10) was obtained for ceramic LT with a1.5-mm thickness/alloy substrate/with cement. This difference was statistically significant. When the effect of cement on the ΔE of ceramics in both substrates was compared, the lowest value (1.1) occurred with ceramic HO with a 1.5-mm thickness/resin substrate, and the highest was observed for ceramic LT with a 1.5-mm thickness/alloy substrate (6.4). This difference was statistically significant. CONCLUSIONS: The substrate color, type and thickness of ceramic, and presence of the cement significantly influenced the resulting optical color. The ΔE values of cemented HO ceramics were lower than that of the LT ceramic.

Relation between aerobic fitness and brain structures in amnestic mild cognitive impairment elderly.

Mild cognitive impairment (aMCI) is a clinical condition, with high risk to develop Alzheimer's disease. Physical exercise may have positive effect on cognition and brain structure in older adults. However, it is still under research whether these influences are true on aMCI subjects with low Ab_42 and high total tau in cerebrospinal fluid (CSF), which is considered a biomarker for AD. Therefore, we aimed to investigate a possible relation between aerobic fitness (AF) and gray matter (GM) volume and AF and white matter (WM) integrity in aMCI with a CSF biomarker. Twenty-two participants with aMCI acquired the images on a 3.0-T MRI. AF was assessed by a graded exercise test on a treadmill. Voxel-based morphometry and tract-based spatial statistic methods were used to analyze the GM volume and WM microstructural integrity, respectively. We correlated AF and GM volume and WM integrity in aMCI (p < 0.05, FWE corrected, cluster with at least five voxels). There was a positive relation between AF and GM volume mostly in frontal superior cortex. In WM integrity, AF was positively correlated with fractional anisotropy and negatively correlated with mean diffusivity and radial diffusivity, all in the same tracts that interconnect frontal, temporal, parietal, and occipital areas (longitudinal fasciculus, fronto-occipital fasciculus, and corpus callosum). These results suggest that aerobic fitness may have a positive influence on protection of brain even in aMCI CSF biomarker, a high-risk population to convert to AD.

Ethological approach to autism spectrum disorders.

The purpose of the study was to develop a new ethogram for the assessment of children and adolescents with autism spectrum disorders (ASD) and intellectual developmental disorder (IDD) and to test whether this instrument accurately distinguishes ASD participants (n = 61) from IDD participants (n = 61). An ethogram with 88 behavior elements was generated, including body postures, verbalizations, facial expressions, motor stereotypies, head postures, gaze behavior, gestures, and interpersonal distance. Significant differences were detected between both groups in classic ASD behaviors; in behaviors that are deficient in ASD according to established theoretical models, such as symbolic play, gaze direction, gaze following, and use of mental state language; in atypical behaviors that have also been described previously in ethological studies with ASD; and in the nonspecific behaviors of ASD, such as walk, look own body, explore, and cry. The predictive success of a diagnosis of ASD in the logistic regression model with the ethogram's factors was 98.4%. The results suggest that this ethogram is a powerful and useful tool for both the detailed study of the social behaviors of autistic children and adolescents, and for discriminating ASD and IDD.

Cognitive and behavioral heterogeneity in genetic syndromes / Heterogeneidade cognitiva e comportamental em síndromes genéticas

OBJECTIVE: this study aimed to investigate the cognitive and behavioral profiles, as well as the psychiatric symptoms and disorders in children with three different genetic syndromes with similar sociocultural and socioeconomic backgrounds. METHODS: thirty-four children aged 6 to 16 years, with Williams-Beuren syndrome (n = 10), Prader-Willi syndrome (n = 11), and Fragile X syndrome (n = 13) from the outpatient clinics of Child Psychiatry and Medical Genetics Department were cognitively assessed through the Wechsler Intelligence Scale for Children (WISC-III). Afterwards, a full-scale intelligence quotient (IQ), verbal IQ, performance IQ, standard subtest scores, as well as frequency of psychiatric symptoms and disorders were compared among the three syndromes. RESULTS: significant differences were found among the syndromes concerning verbal IQ and verbal and performance subtests. Post-hoc analysis demonstrated that vocabulary and comprehension subtest scores were significantly higher in Williams-Beuren syndrome in comparison with Prader-Willi and Fragile X syndromes, and block design and object assembly scores were significantly higher in Prader-Willi syndrome compared with Williams-Beuren and Fragile X syndromes. Additionally, there were significant differences between the syndromes concerning behavioral features and psychiatric symptoms. The Prader-Willi syndrome group presented a higher frequency of hyperphagia and self-injurious behaviors. The Fragile X syndrome group showed a higher frequency of social interaction deficits; such difference nearly reached statistical significance. CONCLUSION: the three genetic syndromes exhibited distinctive cognitive, behavioral, and psychiatric patterns. .

OBJETIVO: investigar o perfil cognitivo e comportamental, sintomas e transtornos psiquiátricos em crianças com três diferentes síndromes genéticas, com antecedentes socioculturais e socioeconômicos semelhantes. MÉTODOS: trinta e quatro crianças, entre 6 e 16 anos, com as síndromes de Williams-Beuren (n = 10), de Prader-Willi (n = 11) e do X-Frágil (n = 13), dos ambulatórios de Psiquiatria Infantil e Genética Médica, foram avaliadas cognitivamente pela Escala Wechsler de Inteligência para Crianças (WISC-III). Posteriormente, o QI total, o QI Verbal, o QI de Execução, os escores ponderados dos subtestes e a frequência de sintomas e transtornos psiquiátricos foram comparados entre as síndromes. RESULTADOS: diferenças significativas foram encontradas entre as síndromes quanto ao QI Verbal e os subtestes verbais e de execução. A análise Post-hoc demonstrou que os escores dos subtestes vocabulário e compreensão foram significativamente superiores na síndrome de Williams-Beuren em relação às síndromes de Prader-Willi e do X-Frágil, e os escores dos subtestes cubos e armar objetos foram significativamente superiores na síndrome de Prader-Willi em relação às síndromes de Williams-Beuren e do X-Frágil. Além disso, houve diferença significativa entre as síndromes quanto às características comportamentais e os sintomas psiquiátricos. O grupo com síndrome de Prader-Willi apresentou maior frequência de hiperfagia e comportamentos autolesivos. Já o grupo com síndrome do X-Frágil apresentou maior frequência do déficit da interação social. Esta diferença quase alcançou a significância estatística. CONCLUSÃO: as três síndromes genéticas ...

Evaluation of UCLA implant-abutment sealing.

PURPOSE: To evaluate the effect of the presence of a prefabricated cobalt-chromium (CoCr) margin in a universal castable long abutment (UCLA) on the sealing capability and fit of the implant-abutment interface. MATERIALS AND METHODS: One-hundred twenty external hexagon implants (SIN) were divided into two groups (n=60 each) to receive UCLA abutments from six manufacturers (n=10 each) either with or without a CoCr margin (n=60 each). Abutments were cast and 12 groups were formed: M (Microplant), I (Impladen), S (SIN), Sv (Signo Vinces), T (TitaniumFix), and B (Bionnovation). Sealing was determined by placing 0.7 µL of 0.1% toluidine blue in the implant wells before abutment torquing. Implant-abutment samples were placed into 2.0-mL vials containing 0.7 mL of distilled water to maintain the implant-abutment interface, and aliquots of 100 µL of water were retrieved at 1, 3, 6, 24, 48, 72, 96, and 144 hour incubation times for measurement of absorbance in a spectrophotometer, and returned for repeated measurements. Two-way ANOVA (P<.05) and Tukey's test were used. Scanning electron microscopy (SEM) was used for observation of the implant-abutment fit. RESULTS: Groups M, Sv, and T without the CoCr margin resulted in complete release of toluidine blue at 1 hour, whereas I, S, and B did so at 3, 24, and 96 hours, respectively. Complete leakage in abutments with the prefabricated margin occurred at 6 hours for S; 24 hours for Sv, T, and B; and 72 hours for M and I. Implant-abutment gaps were observed in all groups. A poorer fit was depicted for groups M and T without the CoCr margin. CONCLUSION: Complete leakage was observed for all UCLA abutments regardless of the presence of the CoCr margin. Implant-abutment gaps were observed in all groups.

Resolution of complex esthetic problems in abnormal anterior teeth: a clinical report.

A conservative treatment is presented for a patient with complex severe esthetic problems related to the presence of anomalous teeth. The patient showed a rare occurrence of macrodontia of the maxillary right lateral incisor and microdontia of the maxillary left lateral incisor. The treatment plan was conservative to avoid tooth extraction, periodontal tissue trauma, and the risk of an unpredictable esthetic outcome. A multidisciplinary treatment involving orthodontic extrusion, endodontic therapy, periodontal therapy, and minimally invasive restorations was performed. A successful outcome was observed after a 2-year follow-up.

Cognitive and behavioral heterogeneity in genetic syndromes.

OBJECTIVE: this study aimed to investigate the cognitive and behavioral profiles, as well as the psychiatric symptoms and disorders in children with three different genetic syndromes with similar sociocultural and socioeconomic backgrounds. METHODS: thirty-four children aged 6 to 16 years, with Williams-Beuren syndrome (n=10), Prader-Willi syndrome (n=11), and Fragile X syndrome (n=13) from the outpatient clinics of Child Psychiatry and Medical Genetics Department were cognitively assessed through the Wechsler Intelligence Scale for Children (WISC-III). Afterwards, a full-scale intelligence quotient (IQ), verbal IQ, performance IQ, standard subtest scores, as well as frequency of psychiatric symptoms and disorders were compared among the three syndromes. RESULTS: significant differences were found among the syndromes concerning verbal IQ and verbal and performance subtests. Post-hoc analysis demonstrated that vocabulary and comprehension subtest scores were significantly higher in Williams-Beuren syndrome in comparison with Prader-Willi and Fragile X syndromes, and block design and object assembly scores were significantly higher in Prader-Willi syndrome compared with Williams-Beuren and Fragile X syndromes. Additionally, there were significant differences between the syndromes concerning behavioral features and psychiatric symptoms. The Prader-Willi syndrome group presented a higher frequency of hyperphagia and self-injurious behaviors. The Fragile X syndrome group showed a higher frequency of social interaction deficits; such difference nearly reached statistical significance. CONCLUSION: the three genetic syndromes exhibited distinctive cognitive, behavioral, and psychiatric patterns.

Correlation between insight dimensions and cognitive functions in patients with deficit and nondeficit schizophrenia.

Previous studies have shown correlations between poor insight and neurocognitive impairment in schizophrenia. Deficit schizophrenia has been associated with worse cognitive functioning and poorer insight. This study aimed at investigating the relationship between insight dimensions (measured by Schedule for the Assessment of Insight-Expanded Version and its factors) and specific neurocognitive functions (assessed through a battery of neuropsychological tests) considering separately patients with deficit (n=29) and nondeficit schizophrenia (n=44), categorized according to the Schedule for the Deficit Syndrome. We found that working memory correlated positively and significantly with awareness of mental illness in both groups. In nondeficit group, awareness of mental illness correlated additionally with verbal fluency and attention. If confirmed by further studies, these results may have important consequences, such as the need of tailoring differently cognitive rehabilitation for each group.

A comparison of the dental health of Brazilian and Canadian independently living elderly.

OBJECTIVE: To compare the dental status of Brazilian and Canadian elderly populations with respect to socioeconomic and quality of life factors. MATERIALS AND METHODS: A total of 496 adults aged 60-75 years, having four or more teeth, and physically and cognitively suitable for a clinical oral examination were included. Subjects answered questions concerning their lifestyle and completed the Geriatric Oral Health Assessment Index (GOHAI) questionnaire. RESULTS: In all populations, the majority were females, aged between 60 and 65 years and married. Although the Canadian New Immigrant population had lower mean income, they had more remaining teeth (23.04 ± 6.1), more functional teeth (sound and restored teeth) (14.92 ± 5.7), more sound teeth (15.40 ± 7.6), but more carious teeth (2.97 ± 3.0). The Brazilian population had higher numbers of restored teeth (12.26 ± 6.8) and fewer remaining teeth (17.80 ± 7.6). In all populations, females, married and younger (60-65 years old) adults were more likely to retain 20 or more teeth. The mean GOHAI scores were similar for Canadians (40.55 ± 5.7) and Canadian New Immigrants (39.28 ± 6.5), but were higher than that among Brazilians (31.97 ± 8.9). CONCLUSIONS: The numbers of remaining teeth were related to greater education and higher income status for Brazilian and Canadian populations. However, Canadian New Immigrants with lower income and education retained more teeth than the other populations.

SEM observation of the bond integrity of fiber-reinforced composite posts cemented into root canals.

OBJECTIVES: To test the null hypothesis that continuity of resin cement/dentin interfaces is not affected by location along the root canal walls or water storage for 3 months when bonding fiber posts into root canals. METHODS: Fiber posts were luted to bovine incisors using four resinous luting systems: Multilink, Variolink II, Enforce Dual and Enforce PV. After cementation, roots were longitudinally sectioned and epoxy resin replicas were prepared for SEM analysis (baseline). The original halves were immersed in solvent, replicated and evaluated. After 3 months water storage and a second solvent immersion, a new set of replicas were made and analyzed. The ratio (%) between the length (mm) of available bonding interface and the actual extension of bonded cement/dentin interface was calculated. RESULTS: Significant lower percent values of bond integrity were found for Multilink (8.25%) and Variolink II (10.08%) when compared to Enforce Dual (25.11%) and Enforce PV (27.0%) at baseline analysis. The same trend was observed after immersion in solvent, with no significant changes. However, bond integrity was significantly reduced after 3 months water storage and a second solvent immersion to values below 5% (Multilink=3.31%, Variolink=1.87%, Enforce Dual=1.20%, and Enforce PV=0.75%). The majority of gaps were depicted at the apical and middle thirds at baseline and after immersion in solvent. After 3 months, gaps were also detected at the cervical third. SIGNIFICANCE: Bond integrity at the cement/dentin interface was surprisingly low after cementation of fiber posts to root canals with all resin cements. That was not significantly altered after immersion in solvent, but was further compromised after 3 months water storage. Gaps were mainly seen at middle and apical thirds throughout the experiment and extended to the cervical third after water storage for 3 months. Bond integrity of fiber posts luted to root canals was affected both by location and water storage.

Bond angle effects on microtensile bonds: laboratory and FEA comparison.

OBJECTIVE: To test the hypothesis that there is a reduction in bond strength when a microtensile load is applied to adhesive junctions prepared at 10, 20 and 30 degrees to the usual perpendicular interface. To evaluate the effect of bond angle and adhesive layer thickness on stress levels within the adhesive joint utilizing FEA. METHODS: Twenty-four non-carious third molars were selected, occlusal enamel removed and polished perpendicular to the long axis of the tooth. The Clearfil SE Bond and Single Bond were applied on the dentin. A 4 mm resin restoration, Z 100, was built up. The teeth were sectioned at 10 degrees, 20 degrees and 30 degrees to the bonding interface (n = 3). The control (n = 3) group had all cuts parallel to the tooth longitudinal axis (0 degrees bond angle). The bond values were calculated in MPa and Two-Way ANOVA and Tukey test applied. FEA was performed (1 mm/side square specimens) to obtain the maximum principal stress (MPS) in the microtensile-model for each bond angle and for varying adhesive thickness from 20 microm to 200 microm for each group. RESULTS: The bond strength results diminish as the angle on the interface increased (P<0.05) for Clearfil SE Bond between 0 (control) and 30 degrees, and for Single Bond between 0 (control) and 10, 20, and 30 degrees. The hypothesis can be fully accepted for Single Bond and partially accepted for Clearfil SE Bond. For the FEA, there was a trend toward decreasing MPS as the bond angle increased, while the MPS for each angled group increased with adhesive layer thickness. SIGNIFICANCE: The MPS results for angled interfaces, exhibited the same trend as the lab values. FEA results indicated an MPS increase with increased adhesive thickness.