DNA damage induced by 7,12-dimethylbenz[a]anthracene in the liver and the mammary gland of rats exposed to polycyclic aromatic hydrocarbon enzyme inducers during perinatal life

The long-lasting modulating effect induced by the prenatal or neonatal exposure to phenobarbital (PB) and aroclor on the genotoxic activity of 7,12-dimethylbenz[a]anthracene (DMBA) in female Sprague-Dawley rats was studied. The effect was measured as DNA damage evaluated in the liver and in the mammary gland of 55-day-old animals, 4 and 24 h after an i.g. injection of 80 mg/kg of DMBA. PB was given per os, i.g. or in drinking water to pregnant females and by i.g. only to neonates or in adult progeny. Aroclor was injected i.g. in prenatal and in neonatal life, and a second dose was given in adult life. Under these experimental conditions it was shown that DNA damage kinetics caused by DMBA are modulated by exposure to PB and, to a minor extent, by aroclor. The amount and persistence of DNA damage were highest when PB was administered to neonates. An average 2-fold increase in the elution constants (K) of DNA in the liver and the mammary gland was observed 4 h after DMBA treatment, as compared to uninduced animals. Repeated enzyme induction by PB seems to reduce DMBA genotoxicity, as shown by a decrease in DNA damage and persistence in the liver and mammary gland. The inducibility of the monooxygenase enzyme system in perinatal life favouring metabolic activation or inactivation of polycyclic aromatic hydrocarbons might be critical in determining individual susceptibility of adult progeny to chemical carcinogenesis by DMBA.     

Early dynamic changes in pulse oximetry signals in preterm newborns with histologic chorioamnionitis.

OBJECTIVE: No reliable clinical markers of histologic chorioamnionitis (HCA), a major and often subclinical cause of prematurity leading to high neonatal morbidity and mortality, are available to date. Increasing evidence indicates myocardial dysfunctions in affected fetuses and newborns. We sought to assess the value of nonlinear dynamics from pulse oximetry signals in identifying affected newborns. DESIGN: Prospective case-control study. SETTING: Tertiary level neonatal intensive care unit, Brindisi Hospital. PATIENTS AND INTERVENTION: Pulse oximetry-derived signals (pulse rate, oxygen saturation, and perfusion index), recorded within the first 1.5 hrs of life, were analyzed for 110 very low-birth-weight infants, of whom 54 had histopathological evidence of HCA. MEASUREMENTS AND MAIN RESULTS: Four different time series parameters were determined for nonlinear dynamical (NLD) analysis. Significantly decreased Lempel-Ziv, Lyapunov largest exponent, and correlation dimension, with significantly increased Hurst values for heart rate and perfusion index (p < .00001), were observed in newborns with HCA. Heart rate Lempel-Ziv 相似文献   

Absence of the inferior labial and lingual frenula in Ehlers-Danlos syndrome

The diagnosis of Ehlers-Danlos syndrome is based on distinctive phenotypical characteristics such as hyperelastic skin and hypermobile joints. To date, no congenital physical markers exist for identifying patients with Ehlers-Danlos syndrome. Absence of the inferior labial (100% sensitivity; 99.4% specificity) and lingual frenulum (71.4% sensitivity; 100% specificity) was found to be associated with classical and hypermobility types of Ehlers-Danlos syndrome.     

Clear aligner orthodontic therapy of rotated mandibular round-shaped teeth: A finite element study

Objective:To evaluate, using the finite element method, the orthodontic rotational movement of a lower second premolar obtained with clear aligners, analyzing different staging and attachment configurations.Materials and Methods:A CAD model including a complete lower dental arch (with element 4.5 mesially rotated 30°) and the corresponding periodontal ligaments, attachments, and aligner was designed and imported to finite element software. Starting from the CAD model, six projects were created to simulate the following therapeutic combinations for correcting element 4.5 position: (1) without attachments, (2) single attachment placed on the buccal surface of element 4.5, (3) three attachments placed on the buccal surfaces of teeth 4.4 to 4.6. For each project, both 1.2° and 3° of aligner activation were considered.Results:All the analyzed configurations revealed a clockwise rotation movement of element 4.5 on the horizontal plane. Models with attachments showed a greater tooth displacement pattern than models without attachments. Simulations with attachments and 3° of aligner activation exhibited the best performance concerning tooth movement but registered high stresses in the periodontal ligaments, far from the ideal stress levels able to produce tooth rotational movement.Conclusions:The model with a single attachment and 1.2° of aligner activation was the most efficient, followed by the three attachment model with the same degree of activation. Aligner activation should not exceed 1.2° to achieve better control of movement and reasonable stress in periodontal structures.     

Morphometric analysis of dental arch form changes in class II patients treated with clear aligners

Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie - The purpose of this study was to evaluate the arch form changes in class&nbsp;II Caucasian patients treated with...     

异常的口腔血管网模式：唐氏综合征的一种新的临床征象

唐氏综合征主要是遗传原因所导致的精神发育迟滞。在这里,作者对该病患儿(n=14)及其表型正常的父母的口腔血管网的高分维、Lem pel-Ziv复杂性和更低的最小道分维(P≤0.0006)进行描述。这种被公认的新征象可以为识别父母生育唐氏综合征患儿潜在的风险提供一种有用的表型标记物。     

Nonsyndromic mental retardation and cryptogenic epilepsy in women with doublecortin gene mutations

DCX mutations cause mental retardation in male subjects with lissencephalypachygyria and in female subjects with subcortical band heterotopia (SBH). We observed four families in which carrier women had normal brain magnetic resonance imaging (MRI) and mild mental retardation, with or without epilepsy. Affected male subjects had SBH or pachygyria-SBH. In two families, the phenotype was mild in both genders. In the first family, we found a tyr138his mutation that is predicted to result in abnormal folding in the small hinge region. In the second family, we found an arg178cys mutation at the initial portion of R2, in the putative beta-sheet structure. Carrier female subjects with normal MRI showed no somatic mosaicism or altered X-inactivation in lymphocytes, suggesting a correlation between mild mutations and phenotypes. In the two other families, with severely affected boys, we found arg76ser and arg56gly mutations within the R1 region that are predicted to affect DCX folding, severely modifying its activity. Both carrier mothers showed skewed X-inactivation, possibly explaining their mild phenotypes. Missense DCX mutations may manifest as non-syndromic mental retardation with cryptogenic epilepsy in female subjects and SBH in boys. Mutation analysis in mothers of affected children is mandatory, even when brain MRI is normal.     

Behavioural disorders in adolescents with early-treated congenital hypothyroidism

This study analyses the possible risk factors for the on-set of behavioural disorders and psychiatric disturbances in a group of 30 early-treated congenital hypothyroidism (CH) subjects (12 children and 18 adolescents) compared with a control group of 116 age-matched normal subjects (58 children and 58 adolescents). The study also allowed us to evaluate the possible age at onset of behavioural disorders. Both the sample's and the controls' behaviours were assessed using a specific diagnostic instrument: Achenbach's and Edelbrock's Child Behaviour Checklist (CBCL). A clinical structured interview, the Diagnostic Interview for Children and Adolescents--Revised (DICA-R) was also administered to 18 adolescents with early-treated CH, in order to determine the presence of psychopathological disturbances. In accordance with literature data, the children and adolescents with early-treated CH showed more behavioural problems than age-matched, normal controls. In the children, a statistically significant difference versus the controls emerged only in their higher delinquent behaviour score, while the adolescents gave, on the CBCL, significantly higher scores compared with controls in the withdrawal, anxiety/depression, thought problems, attention problems and aggressive behaviour scales. In the DICA-R, 44% of adolescents with early-treated CH showed symptoms of anxiety disorder, in particular, separation anxiety disorder with phobic components; 16% showed mood disorder and depression and 11% showed behavioural disorders with attention deficit.