Education about crying in normal infants is associated with a reduction in pediatric emergency room visits for crying complaints.

OBJECTIVE: The primary aim of this study was to determine whether there was any change in visits of 0- to 5-month old infants to the medical emergency room (MER) of a metropolitan pediatric hospital after province-wide implementation of a public health prevention program that teaches new parents about the properties of early crying in normal infants. METHODS: Free-text descriptions of Presenting Complaint and Final Diagnosis on electronic MER clinic visit files were used to classify infants as cases of infant crying not due to disease. Annual crying case visits as a percent of MER visits were analyzed pre- and post-introduction of the prevention program. RESULTS: Before the program, crying case visits represented 724 of 20,394 MER visits (3.5%). The age-specific pattern of MER visits for crying peaked at 6 weeks and was similar to the previously reported age-specific pattern of amounts of crying in the community. After program implementation, crying cases were reduced by 29.5% (p < .001). The most significant reductions were for crying visits in the first to third months of life. CONCLUSION: The findings imply that improved parental knowledge of the characteristics of normal crying secondary to a public health program may reduce MER use for crying complaints in the early months of life.

Perspectives of expectant women and health care providers on birth plans.

OBJECTIVE: A birth plan is a document detailing a woman's preferences and expectations related to labour and delivery. Empirical research exploring the value of birth plans has shown conflicting findings about whether birth plans have a positive or negative effect on labour and delivery, suggesting a need for further study. This study aimed to understand the perspectives of women, health care providers, and support persons regarding the use of birth plans. METHODS: A cross-sectional questionnaire was distributed to a convenience sample of expectant or postpartum women, health care providers, and support persons from January 2012 to March 2012 in British Columbia. RESULTS: In total, 122 women and 110 health care providers and support persons completed the questionnaire. Both women and their attendants viewed the birth plan as being valuable for acting as both a communication and education tool. However, the respondents noted that women may be disappointed or dissatisfied if a birth plan cannot be implemented. The most important elements of a birth plan identified included pain management, comfort measures (e.g., mobility during labour), postpartum preferences (e.g., breastfeeding), atmosphere (e.g., privacy), and birthing beliefs (e.g., cultural views). CONCLUSION: This is the first study to identify advantages and disadvantages of using a birth plan as well as the most important aspects of a birth plan from the perspectives of both women and their attendants in Canada. The findings could be applied to optimize the efficacy of birth plans in Canada and potentially internationally as well.

Objective : Un plan d'accouchement est un document détaillant les préférences et les attentes d'une femme à l'égard du travail et de l'accouchement. Les recherches empiriques explorant la valeur des plans d'accouchement ont obtenu des résultats contradictoires quant à la question de savoir si ces derniers exercent un effet positif ou négatif sur le travail et l'accouchement, ce qui semble souligner la nécessité de procéder à d'autres études sur le sujet. Cette étude avait pour but de comprendre les points de vue des femmes, des fournisseurs de soins et des accompagnateurs à l'égard de l'utilisation de plans d'accouchement. Méthodes : Un questionnaire transversal a été distribué à un échantillon de commodité de femmes enceintes ou ayant accouché, de fournisseurs de soins et d'accompagnateurs entre janvier 2012 et mars 2012 en Colombie-Britannique. Résultats : En tout, 122 femmes et 110 fournisseurs de soins de santé et accompagnateurs ont rempli le questionnaire. Tant les femmes que leurs fournisseurs de soins et de soutien estimaient que le plan d'accouchement était utile à titre d'outil de communication et d'éducation. Toutefois, les répondants ont souligné que les femmes pourraient être déçues ou mécontentes dans les cas où la mise en œuvre du plan d'accouchement s'avère impossible. Parmi les plus importants éléments du plan d'accouchement qui ont été identifiés, on trouvait la maîtrise de la douleur, les mesures visant le confort (p. ex. mobilité pendant le travail), les préférences postpartum (p. ex. allaitement), l'atmosphère (p. ex. intimité) et les croyances quant à l'accouchement (p. ex. aspects culturels). Conclusion : Il s'agit de la première étude à identifier les avantages et les désavantages de l'utilisation d'un plan d'accouchement, ainsi que les aspects les plus importants d'un tel plan, et ce, tant du point de vue des femmes que de celui de leurs fournisseurs de soins et de soutien au Canada. Les résultats pourraient être utilisés aux fins de l'optimisation de l'efficacité des plans d'accouchement au Canada et (potentiellement) à l'étranger.

Expression of Wnt5a in tooth germs and the related signal transduction analysis.

OBJECTIVE: Wnt5a is generally considered a non-canonical Wnt family member and plays an important role in the development of several tissues through regulation of cell fate, proliferation, migration, polarity and death. This study investigates its expression mode in human tooth development and the involved cell signal transduction pathways, as they remain unclear. DESIGN: The expression of Wnt5a was analyzed by immunohistochemistry method. Recombinant adenovirus encoding full-length Wnt5a cDNA was constructed to investigate four cell signal pathways and nine dentinogenesis nuclear transcription factors in response to Wnt5a in human dental papilla cells (HDPCs). RESULTS: Immunostaining revealed that Wnt5a was expressed in enamel epithelium cells from the bud stage, and in odontoblast layers and dental papilla tissues from early bell stage of human tooth development onward. Western blot analysis indicated that p42/44 MAPK, p38 MAPK, JNK and AKT signal pathways could be phosphorylated by WNT5A. RT-PCR analysis showed that Wnt5a increased the expression of DLX1, DLX2, LEF1, MSX2, PAX9 and RUNX2 mRNA, but decreased BARX1 and PITX2 mRNA. CONCLUSIONS: It was concluded that WNT5A is expressed in human tooth development, and that p42/44 MAPK, p38 MAPK, JNK and AKT signal pathways and DLX1, DLX2, LEF1, MSX2, PAX9, RUNX2 could be activated by Wnt5a.

A large X-chromosomal deletion is associated with microphthalmia with linear skin defects (MLS) and amelogenesis imperfecta (XAI).

A female patient is described with clinical symptoms of both microphthalmia with linear skin defects (MLS or MIDAS) and dental enamel defects, having an appearance compatible with X-linked amelogenesis imperfecta (XAI). Genomic DNA was purified from the patient's blood and semiquantitative multiplex PCR revealed a deletion encompassing the amelogenin gene (AMELX). Because MLS is also localized to Xp22, genomic DNA was subjected to array comparative genomic hybridization, and a large heterozygous deletion was identified. Histopathology of one primary and one permanent molar tooth showed abnormalities in the dental enamel layer, and a third tooth had unusually high microhardness measurements, possibly due to its ultrastructural anomalies as seen by scanning electron microscopy. This is the first report of a patient with both of these rare conditions, and the first description of the phenotype resulting from a deletion encompassing the entire AMELX gene. More than 50 additional genes were monosomic in this patient.

The leucine-rich amelogenin peptide alters the amelogenin null enamel phenotype.

INTRODUCTION: The amelogenin proteins secreted by ameloblasts during dental enamel development are required for normal enamel structure. Amelx null (KO) mice have hypoplastic, disorganized enamel similar to that of human patients with mutations in the AMELX gene, and provide a model system for studies of the enamel defect amelogenesis imperfecta. Because many amelogenin proteins are present in developing enamel due to RNA alternative splicing and proteolytic processing, understanding the function of individual amelogenins has been challenging. PURPOSE: Our objective was to better understand the role of LRAP, a 59 amino acid leucine-rich amelogenin peptide, in the development of enamel. APPROACH: Teeth from transgenic mice that express LRAP under control of the Amelx regulatory regions were analyzed for mechanical properties, and transgenic males were mated with female KO mice. Male offspring with a null background that were transgene positive or transgene negative were compared to determine phenotypic differences using microcomputed tomography (microCT) and scanning electron microscopy (SEM). RESULTS: Nanoindentation revealed no differences between LRAP transgenic and wild-type murine enamel. Using microCT, LRAPKO enamel volume and density measurements were similar to those from KO mice. However, in etched samples examined by SEM, the organization of the enamel rod pattern was altered by the presence of the LRAP transgene. CONCLUSIONS: The presence of LRAP leads to changes in enamel appearance compared to enamel from KO mice. Expression of a combination of amelogenin transgenes in KO mice may lead to rescue of the individual characteristics of normal enamel.

Partial rescue of the amelogenin null dental enamel phenotype.

The amelogenins are the most abundant secreted proteins in developing dental enamel. Enamel from amelogenin (Amelx) null mice is hypoplastic and disorganized, similar to that observed in X-linked forms of the human enamel defect amelogenesis imperfecta resulting from amelogenin gene mutations. Both transgenic strains that express the most abundant amelogenin (TgM180) have relatively normal enamel, but strains of mice that express a mutated amelogenin (TgP70T), which leads to amelogenesis imperfecta in humans, have heterogeneous enamel structures. When Amelx null (KO) mice were mated with transgenic mice that produce M180 (TgM180), the resultant TgM180KO offspring showed evidence of rescue in enamel thickness, mineral density, and volume in molar teeth. Rescue was not observed in the molars from the TgP70TKO mice. It was concluded that a single amelogenin protein was able to significantly rescue the KO phenotype and that one amino acid change abrogated this function during development.

Comparison of body weight and gene expression in amelogenin null and wild-type mice.

Amelogenin (AmelX) null mice develop hypomineralized enamel lacking normal prism structure, but are healthy and fertile. Because these mice are smaller than wild-type mice prior to weaning, we undertook a detailed analysis of the weight of mice and analyzed AmelX expression in non-dental tissues. Wild-type mice had a greater average weight each day within the 3-wk period. Using reverse transcription-polymerase chain reaction (RT-PCR), products of approximately 200 bp in size were generated from wild-type teeth, brain, eye, and calvariae. DNA sequence analysis of RT-PCR products from calvariae indicated that the small amelogenin leucine-rich amelogenin peptide (LRAP), both with and without exon 4, was expressed. No products were obtained from any of the samples from the AmelX null mice. We also isolated mRNAs that included AmelX exons 8 and 9, and identified a duplication within the murine AmelX gene with 91% homology. Our results add additional support to the hypothesis that amelogenins are multifunctional proteins, with potential roles in non-ameloblasts and in non-mineralizing tissues during development. The smaller size of AmelX null mice could potentially be explained by the lack of LRAP expression in some of these tissues, leading to a delay in development.

Effects of sodium fluoride on the actin cytoskeleton of murine ameloblasts.

Fluoride is associated with a decrease in the incidence of dental caries, but excess fluoride can lead to enamel fluorosis, a defect that occurs during tooth enamel formation. In fibroblasts, the Arhgap gene encodes a RhoGAP, which regulates the small G protein designated RhoA. Fluoride treatment of fibroblasts inactivates RhoGAP, thereby activating RhoA, which leads to elevation of filamentous actin (F-actin). Since RhoA is a molecular switch, our hypothesis is that in ameloblasts, fluoride may alter the cytoskeleton through interference with the Rho signaling pathway. Our objective was to measure the effects of sodium fluoride on F-actin using tooth organ culture and confocal microscopy. The results indicated that cellular responses to fluoride include elevation of F-actin in ameloblasts. It was concluded from immunohistochemistry, RT-PCR and confocal approaches that the components of the Rho pathway are present in ameloblasts, and that the response to fluoride involves the Rho/ROCK pathway.