Uncommon dentigerous cyst related to a maxillary lateral incisor in a 03-year-old boy

Background

The dentigerous cyst is usually defined as a cystic cavity that surrounds the crown of an unerupted tooth on the cementoenamel junction. The present article reports a case of an uncommon dentigerous cyst, highlighting its clinical, radiographic and surgical characteristics and discussing the aspects related to its development in infancy.

Case report

A 03-year-old boy patient presented with an extensive radiolucid area involving the crown of the right maxillary lateral incisor. A surgical excision was performed. Anatomopathological examination revealed a cystic tissue with a fibrous wall surrounded by nonkeratinized stratified squamous oral epithelium, without atypia.

Conclusion

It is possible that the dentigerous cyst grows in the dental germ in any stage of development and not only in the follicle of a tooth with calcified crown attached to the cementoenamel junction.     

Suggestive evidence for association between L‐type voltage‐gated calcium channel (CACNA1C) gene haplotypes and bipolar disorder in Latinos: a family‐based association study

Objectives: Through recent genome‐wide association studies (GWASs), several groups have reported significant association between variants in the calcium channel, voltage‐dependent, L‐type, alpha 1C subunit (CACNA1C) and bipolar disorder (BP) in European and European‐American cohorts. We performed a family‐based association study to determine whether CACNA1C is associated with BP in the Latino population. Methods: This study included 913 individuals from 215 Latino pedigrees recruited from the USA, Mexico, Guatemala, and Costa Rica. The Illumina GoldenGate Genotyping Assay was used to genotype 58 single‐nucleotide polymorphisms (SNPs) that spanned a 602.9‐kb region encompassing the CACNA1C gene including two SNPs (rs7297582 and rs1006737) previously shown to associate with BP. Individual SNP and haplotype association analyses were performed using Family‐Based Association Test (version 2.0.3) and Haploview (version 4.2) software. Results: An eight‐locus haplotype block that included these two markers showed significant association with BP (global marker permuted p = 0.0018) in the Latino population. For individual SNPs, this sample had insufficient power (10%) to detect associations with SNPs with minor effect (odds ratio = 1.15). Conclusions: Although we were not able to replicate findings of association between individual CACNA1C SNPs rs7297582 and rs1006737 and BP, we were able to replicate the GWAS signal reported for CACNA1C through a haplotype analysis that encompassed these previously reported significant SNPs. These results provide additional evidence that CACNA1C is associated with BP and provides the first evidence that variations in this gene might play a role in the pathogenesis of this disorder in the Latino population.     

Using Data Linkage to Investigate Inconsistent Reporting of Self-Harm and Questionnaire Non-Response

The objective of this study was to identify factors that may account for the disproportionately high prevalence of suicidal behaviors among Hispanic/Latina youth by examining whether associations of health risk behaviors with suicidal ideation and suicide attempts vary by race/ethnicity among female students. Data from the school-based 2007 national Youth Risk Behavior Survey were analyzed. Analyses were conducted among female students in grades 9 through 12 and included 21 risk behaviors related to unintentional injuries and violence; tobacco use; alcohol and other drug use; sexual behaviors that contribute to unintended pregnancy and sexually transmitted infections, including human immunodeficiency virus; physical activity; obesity and weight control; and perceived health status. With the exception of physical activity behaviors and obesity, all risk behaviors examined were associated with suicidal ideation and suicide attempts. Associations of risk behaviors with suicidal ideation varied by race/ethnicity for 5 of 21 behaviors, and for 0 of 21 behaviors for suicide attempts. Stratified analyses provided little insight into factors that may account for the higher prevalence of suicidal behaviors among Hispanic/Latina female students. These results suggest that the increased risk of suicidal behaviors among Hispanic/Latina female students cannot be accounted for by differential associations with these selected risk behaviors. Other factors, such as family characteristics, acculturation, and the socio-cultural environment, should be examined in future research.     

Radicular dens invaginatus in a mandibular premolar: cone-beam computed tomography findings of a rare anomaly

Dens invaginatus is a rare developmental anomaly and its etiology remains controversial. Radicular dens invaginatus is an unusual dental anomaly. The aims of this paper are to report the radiographic and tomographic findings of a case of radicular dens invaginatus and to discuss the relevant features associated with this dental anomaly. A 16-year-old female was referred to a private oral radiology clinic for orthodontic evaluation. Radiographically, a morphological alteration to the root portion of the right mandibular first premolar and the presence of a discrete radiolucent periapical lesion were observed. The diagnosis was only elucidated after cone-beam computed tomography (CBCT). The CBCT images revealed enlargement of the root, and a dilated invagination with limited enamel that had its open site along the lateral portion of the root without evidence of buccal and lingual expansion. The diagnosis of radicular dens invaginatus was then established.     

Effects of training multiple form classes on acquisition,generalization and maintenance of word retrieval in a single subject

Abstract

A study by McNeil et al. reported no generalization effects in two individuals with aphasia following application of a word finding treatment in which subjects were trained sequentially on lexical items arranged by form class. The present investigation examined, in one of the two subjects from the original study, whether training on lexical items from a variety of form classes concurrently would result in greater response generalization than was observed previously in this subject. Results replicated earlier findings with positive acquisition and maintenance effects and little evidence of generalization to untrained items within or across form classes.     

Excitatory actions of GABA in developing chick vestibular afferents: Effects on resting electrical activity

The aim of this study was to characterize the effect of γ-aminobutyric acid (GABA) in the resting multiunit activity of the vestibular afferents during development using the isolated inner ear of embryonic and postnatal chickens (E15-E21 and P5). GABA (10⁻³ to 10⁻⁵ M; n = 133) and muscimol (10⁻³M) elicited an increase in the frequency of the basal discharge of the vestibular afferents. We found that GABA action was dose-dependent and inversely related to animal age. Thus, the largest effect was observed in embryonic ages such as E15 and E17 and decreases in E21 and P5. The GABA_A receptor antagonists, bicuculline (10⁻⁵M; n = 10) and picrotoxin (10⁻⁴M; n = 10), significantly decreased the excitatory action of GABA and muscimol (10⁻³M). Additionally, CNQX 10⁻⁶M, MCPG 10⁻⁵M and 7ClKyn 10⁻⁵M (n = 5) were co-applied by bath substitution (n = 5). Both the basal discharge and the GABA action significantly decreased in these experimental conditions. The chloride channel blocker 9-AC 0.5 mM produced an important reduction in the effect of GABA 10⁻³ (n = 5) and 10⁻⁴M (n = 5). Thus, our results suggest an excitatory role of GABA in the resting activity of the vestibular afferents that can be explained by changes in the gradient of concentration of Cl⁻ during development. We show for the first time that the magnitude of this GABA effect decreases at later stages of embryonic and early postnatal development. Taking into account the results with glutamatergic antagonists, we conclude that GABA has a presynaptic action but is not the neurotransmitter in the vestibular afferent synapses, although it could act as a facilitator of the spontaneous activity and may regulate glutamate release. Synapse 67:374–381, 2013. © 2013 Wiley Periodicals, Inc.