The spectrum of orofacial manifestations in systemic sclerosis: a challenging management.

Systemic sclerosis (SSc) is a rare multisystem connective tissue disorder characterized by the triad fibrosis, vasculopathy and immune dysregulation. This chronic disease has a significant impact on the orofacial region that is involved in more than two-thirds of the cases. SSc patients can show a wide array of oral manifestations, which are usually associated with a severe impairment of the quality of life. They often present a decreased the salivary flow and a reduced mouth opening that contribute substantially to the worsening of the oral health status. Therefore, SSc patients require specific and multidisciplinary interventions that should be initiated as early as possible. The identification of specific radiological and clinical signs at the early stage will improve the management of such patients. This study reviews the wide spectrum of orofacial manifestations associated with SSc and suggests clues for the oral management that remains challenging.

Airway Phenotypes and Nocturnal Wearing of Dentures in Elders with Sleep Apnea.

The objective of this study was to examine to what extent the anatomic characteristics of the upper airway can influence the effect of nocturnal wearing of dentures on the sleep of edentulous elders with untreated sleep apnea. This study used the data from a randomized crossover clinical trial and an exploratory approach to address its objectives. Cone beam computed tomography scans of 65 edentulous individuals (female, n = 37; male, n = 28; mean ± SD age, 74.54 ± 6.42 y) with untreated obstructive sleep apnea (OSA) were used to identify anatomic variables. Polysomnography data were collected by means of one portable overnight recording. The respiratory variable values, including apnea-hypopnea index (AHI), with and without denture worn during sleep were used to calculate the change. Statistical analyses included multiple linear regressions, cluster analysis, and binary logistic regressions. A receiver operator characteristic curve was used to illustrate the accuracy of the statistical model. The regression model explained 15.8% (R2) of AHI change. An increase in the lateral dimension of the minimum cross-sectional area was associated with a decrease in AHI, oxygen desaturation index, and respiratory arousal index changes (P ≤ 0.041). Furthermore, an increase in the length of the hypopharynx was associated with an increase in AHI and oxygen desaturation index changes (P ≤ 0.027). An increase in the lateral dimension of the minimum cross-sectional area of the upper airway was associated with a decreased likelihood of being in the group having a worsened AHI (odds ratio = 0.85; 95% CI, 0.76 to 0.95; P = 0.006). An increase in the length of the oropharynx was associated with an increased likelihood of having increased AHI (odds ratio = 1.10; 95% CI, 1.01 to 1.20; P = 0.026). The nocturnal aggravation of respiratory variables in edentulous individuals with OSA who wear dentures at night can be linked to certain anatomic characteristics of the upper airway. Replication of these findings may open novel avenues for personalized advice regarding nocturnal wearing of dentures in edentulous individuals with OSA (ClinicalTrials.gov: NCT01868295).

X-linked and autosomal recessive Hypohidrotic Ectodermal Dysplasia: genotypic-dental phenotypic findings.

Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal development of ectodermal structures and its molecular etiology corresponds to mutations of EDA-EDAR genes. The aim of this study was first to investigate the genotype and dental phenotype associated with HED and second, to explore possible correlations between dental features and molecular defects. A total of 27 patients from 24 unrelated families exhibiting clinical signs of HED (22 XLHED males, 5 autosomal recessive forms) were retrospectively included. In the sample, 25 different mutations on EDA and EDAR genes were detected; 10 were not previously described. EDA and EDAR mutations corresponded respectively to 80.0% and 20.0% of the mutations. The dental phenotype analysis revealed a mean number of primary and permanent missing teeth ranging respectively from 14.5 (4-20) to 22.5 (10-28); the majority of the patients exhibited dysmorphic teeth. Overall, no differential expression in the degree of oligodontia according to either the mutated gene, the mutated functional sub-domains, or the mutation type, could be observed. Nevertheless, the furin group exhibited severe phenotypes unobserved in the TNF group. Significant differences in the number of some primary missing teeth (incisor and canine) related to EDA-EDAR genes defects were detected for the first time between XLHED and autosomal recessive HED, suggesting differential local effects of EDA-EDAR genes during odontogenesis. The present genotypic-phenotypic findings may add to the knowledge of the consequences of the molecular dysfunction of EDA-NF-kB in odontogenesis, and could be helpful in genetic counseling to distinguish autosomal forms from other HED syndromes.

Quantification of taurodontism: interests in the early diagnosis of hypohidrotic ectodermal dysplasia.

OBJECTIVE: The aim of this study was to provide a quantification of taurodontism in Hypohidrotic Ectodermal Dysplasia (HED) and to report its occurrence in a cohort of HED patients to assess phenotypic-genotypic correlations. PATIENTS AND METHODS: Of 68 HED patients retrospectively reviewed, 16 patients aged 7-51 years were selected and compared with a control sample (n = 351). The pulp surface index of the first lower permanent molar was calculated from the panoramic radiograph of each individual, and statistical comparisons between the HED patients and the control sample were performed. RESULTS: Whatever the genetic disorder, 81.25% of the HED patients exhibited a relative enlargement (>or=1 s.d.) of the pulp. Major deviations (>5 s.d.) were respectively related to men affected by large deletion of the EDA gene or missense mutation. The autosomal recessive form was linked to a relative moderate pulp enlargement (3.44 s.d.). In NEMO forms, the increase of pulp size in men appeared to be less marked than in EDA mutations. CONCLUSION: This study provides for the first time an objective assessment of pulp enlargement in HED patients, and the various degrees of taurodontism depicted could be interesting dental phenotypic markers of HED forms.

Cell context reveals a dual role for Maf in oncogenesis.

Maf b-Zip transcription factors are involved in both terminal differentiation and oncogenesis. To investigate this apparent contradiction, we used two different primary cell types and performed an extensive analysis of transformation parameters induced by Maf proteins. We show that MafA and c-Maf are potent oncogenes in chicken embryo fibroblasts, while MafB appears weaker. We also provide the first evidence that MafA can confer growth factor independence and promote cell division at low density. Moreover, using MafA as a model, we identified several parameters that are critical for Maf transforming activities. Indeed, MafA ability to induce anchorage-independent cell growth was sensitive to culture conditions. In addition, the transforming activity of MafA was dependent on its phosphorylation state, since mutation on Ser65 impaired its ability to induce growth at low density and anchorage-independent growth. We next examined transforming activity of large Maf proteins in embryonic neuroretina cells, where they are known to induce differentiation. Unlike v-Jun, MafA, MafB and c-Maf did not show oncogenic activity in these cells. Moreover, they counteracted transformation induced by constitutive activation of the Ras/Raf/MEK pathway. Taken together, our results show that Maf proteins could display antagonistic functions in oncogenesis depending on the cellular context, and support a dual role for Maf as both oncogenes and tumor suppressor-like proteins.

Induction of postmitotic neuroretina cell proliferation by distinct Ras downstream signaling pathways.

Ras-induced cell transformation is mediated through distinct downstream signaling pathways, including Raf, Ral-GEFs-, and phosphatidylinositol 3-kinase (PI 3-kinase)-dependent pathways. In some cell types, strong activation of the Ras-Raf-MEK-extracellular signal-regulated kinase (ERK) cascade leads to cell cycle arrest rather than cell division. We previously reported that constitutive activation of this pathway induces sustained proliferation of primary cultures of postmitotic chicken neuroretina (NR) cells. We used this model system to investigate the respective contributions of Ras downstream signaling pathways in Ras-induced cell proliferation. Three RasV12 mutants (S35, G37, and C40) which differ by their ability to bind to Ras effectors (Raf, Ral-GEFs, and the p110 subunit of PI 3-kinase, respectively) were able to induce sustained NR cell proliferation, although none of these mutants was reported to transform NIH 3T3 cells. Furthermore, they all repressed the promoter of QR1, a neuroretina growth arrest-specific gene. Overexpression of B-Raf or activated versions of Ras effectors Rlf-CAAX and p110-CAAX also induced NR cell division. The mitogenic effect of the RasC40-PI 3-kinase pathway appears to involve Rac and RhoA GTPases but not the antiapoptotic Akt (protein kinase B) signaling. Division induced by RasG37-Rlf appears to be independent of Ral GTPase activation and presumably requires an unidentified mechanism. Activation of either Ras downstream pathway resulted in ERK activation, and coexpression of a dominant negative MEK mutant or mKsr-1 kinase domain strongly inhibited proliferation induced by the three Ras mutants or by their effectors. Similar effects were observed with dominant negative mutants of Rac and Rho. Thus, both the Raf-MEK-ERK and Rac-Rho pathways are absolutely required for Ras-induced NR cell division. Activation of these two pathways by the three distinct Ras downstream effectors possibly relies on an autocrine or paracrine loop, implicating endogenous Ras, since the mitogenic effect of each Ras effector mutant was inhibited by RasN17.

Phosphorylation of MafA is essential for its transcriptional and biological properties.

We previously described the identification of quail MafA, a novel transcription factor of the Maf bZIP (basic region leucine zipper) family, expressed in the differentiating neuroretina (NR). In the present study, we provide the first evidence that MafA is phosphorylated and that its biological properties strongly rely upon phosphorylation of serines 14 and 65, two residues located in the transcriptional activating domain within a consensus for phosphorylation by mitogen-activated protein kinases and which are conserved among Maf proteins. These residues are phosphorylated by ERK2 but not by p38, JNK, and ERK5 in vitro. However, the contribution of the MEK/ERK pathway to MafA phosphorylation in vivo appears to be moderate, implicating another kinase. The integrity of serine 14 and serine 65 residues is required for transcriptional activity, since their mutation into alanine severely impairs MafA capacity to activate transcription. Furthermore, we show that the MafA S14A/S65A mutant displays reduced capacity to induce expression of QR1, an NR-specific target of Maf proteins. Likewise, the integrity of serines 14 and 65 is essential for the MafA ability to stimulate expression of crystallin genes in NR cells and to induce NR-to-lens transdifferentiation. Thus, the MafA capacity to induce differentiation programs is dependent on its phosphorylation.

The hormone melatonin: Animal studies.

The Melatonin (MLT), secreted rhythmically by the pineal, is an efferent hormonal signal of the circadian clock. MLT presents overall pleitropic effects but it is the role of MLT as a hormonal circadian signal which is the best documented. MLT-receptors are present in numerous structures/organs and the MLT is now considered as an endogenous synchronizer within the circadian system. The presence of MLT-receptors within the circadian clock, explains that exogenous MLT is a chronobiotic drug. Trials in humans, have confirmed the efficacy of MLT in circadian rhythm disorders. Subtypes of MLT-receptors have been characterized (MT1 and MT2). Striking differences are observed in the distribution pattern of these 2 subtypes. Up to now, MTL-analogues commercialized as drugs, are all non-specific MT1/MT2 agonists acting on the SCN. The development of new specific agonists/antagonists for both subtypes, the identification of the link between MLT target sites within different parts of the brain or the body and the association of specific MLT receptor subtypes and particular physiological effects open great therapeutic potential.

Quantitative characterization of morphological polymorphism of handwritten characters loops.

A methodology based on Fourier descriptors that was previously validated has been applied to 13 writers in order to quantify the polymorphism degree of the shape of the loops of the handwritten characters a, d, o and q. In a first step, the discriminating power of the parameters extracted from these letters was investigated. The loop of the letter d appeared to be the most discriminant with a correct classification rate of 82.4%, whereas the least discriminant one was the loop of the letter o (69.7%). The second aim of the study was to extract grouping characteristics which make it possible to discriminate between writer sets, whatever the letter. Trends in the writing of loops could effectively be shown: the 13 writers of the study were separated into five main groups according to the shape and surface of their loops. The most discriminating features between the writer groups were the importance of the loops elongation and the surface of the loops. Finally, the differences between writers belonging to distinct groups could be characterized more precisely, and differences between writers belonging to the same group were revealed; the individual writings were distinguished by the variability of the parameters of shape and surface of their loops and the morphological distances between its different letters. The correct classification rates reached in this study suggest that carrying out an expertise of fragmentary samples of handwriting comprising only some loops is completely possible.

Characterization of a novel quiescence responsive element downregulated by v-Src in the promoter of the neuroretina specific QR1 gene.

The neuroretina is a functional unit of the central nervous system which arises through successive steps of division, growth arrest and differentiation of neuroectodermal precursors. Postmitotic quail neuroretina (QNR) cells are conditionally induced to divide upon infection with temperature sensitive mutants of Rous sarcoma virus (RSV), since QNR cell division can be arrested by either inactivating p60v-Src at the nonpermissive temperature (41 degrees C) or by serum deprivation at 37 degrees C. We are studying the transcriptional control of QR1, a neuroretina specific gene, whose expression is down-regulated in proliferating cells at 37 degrees C and is fully restored when these cells are made quiescent. We previously showed that this quiescence specific upregulation implicates a promoter region named A box, which binds Maf transcription factors. We report the identification of the C box, a second promoter sequence that activates QR1 transcription in non dividing cells. This sequence is able to form two DNA-protein complexes, one of which (C4) is predominantly detected in growth arrested NR cells. We identified the DNA binding site for C4 and described mutations that abolish both C4 binding and promoter activity in quiescent cells. Moreover, we show that a multimerized C box is able to stimulate a heterologous promoter in non dividing cells and constitutes, therefore, a novel quiescence responsive enhancer. Finally, we report that QR1 transcriptional response to cell quiescence requires cooperation between the C box and A box.

mafA, a novel member of the maf proto-oncogene family, displays developmental regulation and mitogenic capacity in avian neuroretina cells.

Transcription factors of the Maf proto-oncogene family have been shown to participate in the regulation of several differentiation specific genes. We previously reported that a member(s) of this family is involved in the regulation of the neuroretina specific gene, QR1, through a promoter region, designated the A box, that is closely related to the Maf recognition element (MARE). We undertook an identification of Maf family genes expressed in the quail neuroretina (QNR) and we report the isolation of mafA, a gene encoding a novel member of the large Maf proteins subgroup. Expression of this gene is developmentally regulated in the neuroretina. MafA is able to bind to MARE sequence and to heterodimerize with v-Maf, MafB, Jun and Fos, but not with the small MafF and MafK proteins. Accordingly, it is able to transactivate the QR1 promoter A box. We also show that increased expression of mafA induces sustained proliferation of postmitotic QNR cells.

Quantification of the shape of handwritten characters: a step to objective discrimination between writers based on the study of the capital character O.

In view of contributing to the scientific validation of the individuality of handwriting, the testing of the two so called fundamental laws of handwriting--1: no two people write exactly alike; 2: no one person writes the same word exactly the same way twice--was approached by analysing the shape of 445 handwritten capital characters O produced by three individuals. A methodology based on classical Fourier descriptors was applied to the characters contours, which were extracted through an automated procedure of image analysis. Precise individual characterization of the shape was possible through Fourier analysis. Within-writer variability of the shape of character O for the writers selected could be shown in an objective and quantitative way through the statistical analysis of the Fourier descriptors. It was demonstrated that this polymorphism differed between the three writers. Differentiation between writers was quantitatively demonstrated by discriminant analysis of the Fourier descriptors, and by the existence of marked morphological distances between the set of characters O of each writer. The degree of dissimilitude of the character O writings could, thus, be assessed. Because of relatively reduced within-writer variability and a pronounced differentiation between the writers, a morphological profile could be established and discrimination between writers could be obtained through the quantification of the shape of one handwritten character.

Shape of the orbital opening: individual characterization and analysis of variability in modern humans, Gorilla gorilla, and Pan troglodytes.

The description of the human orbital shape is principally qualitative in the classical literature, and characterised by adjectives such as circular, rectangular or quadrangular. In order to provide a precise quantification and interpretation of this shape, a study based on automatic image analysis and Fourier analysis was carried out on 45 human skulls (30 males, 15 females), and for comparison on 61 skulls of Gorilla gorilla (40 males, 21 females), and 34 skulls of Pan troglodytes (20 males, 14 females). Sexual dimorphism in the shape of the orbital opening was not demonstrated. Its dominant morphological features could be characterized by Fourier analysis; elliptical elongation and quadrangularity were dominant morphological features of the shape of the orbital opening in the three species. Elliptical elongation was more marked in humans and Pan, whereas quadrangularity was particularly emphasized in Gorilla. An intraspecific variability of the shape of the orbital opening existed in humans, Gorilla and Pan, and seemed close in the three species. Interspecific partition between humans, Gorilla and Pan was demonstrated despite the variability observed in the three species studied. Interspecific differences between Gorilla and the Pan-humans group were principally explained by the differences in quadrangularity, and by differences in orientation of triangularity and pentagonality. Differences in the shape of the orbital opening between humans and Pan were principally explained by differences in hexagonality, and by differences in orientation of quadrangularity. A closeness of shape between some humans and some individuals in Pan and, to a lesser degree, with some individuals in Gorilla was observed, demonstrating the existence of a morphological continuum of the shape of the orbital opening in hominoids.

Bayes factor for investigative assessment of selected handwriting features.

This paper extends previous research on the use of multivariate continuous data in comparative handwriting examinations, notably for gender classification. A database has been constructed by analyzing the contour shape of loop characters of type a and d by means of Fourier analysis, which allows characters to be described in a global way by a set of variables (e.g., Fourier descriptors). Sample handwritings were collected from right- and left-handed female and male writers. The results reported in this paper provide further arguments in support of the view that investigative settings in forensic science represent an area of application for which the Bayesian approach offers a logical framework. In particular, the Bayes factor is computed for settings that focus on inference of gender and handedness of the author of an incriminated handwritten text. An emphasis is placed on comparing the efficiency for investigative purposes of characters a and d.

The use of the likelihood ratio for evaluative and investigative purposes in comparative forensic handwriting examination.

This paper extends previous research and discussion on the use of multivariate continuous data, which are about to become more prevalent in forensic science. As an illustrative example, attention is drawn here on the area of comparative handwriting examinations. Multivariate continuous data can be obtained in this field by analysing the contour shape of loop characters through Fourier analysis. This methodology, based on existing research in this area, allows one describe in detail the morphology of character contours throughout a set of variables. This paper uses data collected from female and male writers to conduct a comparative analysis of likelihood ratio based evidence assessment procedures in both, evaluative and investigative proceedings. While the use of likelihood ratios in the former situation is now rather well established (typically, in order to discriminate between propositions of authorship of a given individual versus another, unknown individual), focus on the investigative setting still remains rather beyond considerations in practice. This paper seeks to highlight that investigative settings, too, can represent an area of application for which the likelihood ratio can offer a logical support. As an example, the inference of gender of the writer of an incriminated handwritten text is forwarded, analysed and discussed in this paper. The more general viewpoint according to which likelihood ratio analyses can be helpful for investigative proceedings is supported here through various simulations. These offer a characterisation of the robustness of the proposed likelihood ratio methodology.

Consequences of X-linked hypohidrotic ectodermal dysplasia for the human jaw bone.

Mutations of the Eda gene, which encodes for ectodysplasin-A1, result in X-linked hypohydrotic ectodermal dysplasia (XLHED). This pathology may lead to severe oligodontia, subsequently requiring implant therapy. Since Eda is suspected to participate in bone development, the jaw bone status was investigated in XLHED patients in order to adjust the surgical protocol. Using computed tomography, densitometric profiles and 3D reconstructions, the bone structure was analyzed and compared to that of control individuals; our results showed that the morphological changes comprised mandibular bone flattening. Craniofacial CT scans showed medullary bone hyperdensity, including in the mandibular symphysis area, where implants must be placed. These alterations in bone structure were also observed in locations where the presence/absence of teeth cannot interfere. If the changes in jaw bone morphology can be a consequence of oligodontia, the changes in bone structure seem to be tooth-independent and suggest a direct effect of the mutation on bone formation and/or remodeling.

Dento-craniofacial phenotypes and underlying molecular mechanisms in hypohidrotic ectodermal dysplasia (HED): a review.

The hypohidrotic ectodermal dysplasias (HED) belong to a large and heterogeneous nosological group of polymalfomative syndromes characterized by dystrophy or agenesis of ectodermal derivatives. Molecular etiologies of HED consist of mutations of the genes involved in the Ectodysplasin (EDA)-NF-kappaB pathway. Besides the classic ectodermal signs, craniofacial and bone manifestations are associated with the phenotypic spectrum of HED. The dental phenotype of HED consists of various degrees of oligodontia with other dental abnormalities, and these are important in the early diagnosis and identification of persons with HED. Phenotypic dental markers of heterozygous females for EDA gene mutation-moderate oligodontia, conical incisors, and delayed dental eruption-are important for individuals giving reliable genetic counseling. Some dental ageneses observed in HED are also encountered in non-syndromic oligodontia. These clinical similarities may reflect possible interactions between homeobox genes implicated in early steps of odontogenesis and the Ectodysplasin (EDA)-NF-kappaB pathway. Craniofacial dysmorphologies and bone structural anomalies are also associated with the phenotypic spectrum of persons with HED patients. The corresponding molecular mechanisms involve altered interactions between the EDA-NF-kappaB pathway and signaling molecules essential in skeletogenic neural crest cell differentiation, migration, and osteoclastic differentiation. Regarding oral treatment of persons with HED, implant-supported prostheses are used with a relatively high implant survival rate. Recently, groundbreaking experimental approaches with recombinant EDA or transgenesis of EDA-A1 were developed from the perspective of systemic treatment and appear very promising. All these clinical observations and molecular data allow for the specification of the craniofacial phenotypic spectrum in HED and provide a better understanding of the mechanisms involved in the pathogenesis of this syndrome.

Size influence on shape of handwritten characters loops.

In the practice of forensic handwriting experts, the size of the writing on a questioned document may be different from that of known samples. In this study, the hypothesis of shape invariance of handwritten closed loops across size increasing was tested. A Fourier methodology was applied to 2325 small letters (591 a loops, 547 d loops, 596 o loops and 591 q loops) and 692 enlarged letters (162 a loops, 173 d loops, 173 o loops and 184 q loops), in a population of 13 writers who were asked to write letters in their usual size and about three times larger. Most of the writers presented similar modifications when increasing the size of the loops; they produced enlarged loops significantly more round and less slanted towards the right or the left. Furthermore, a discrimination was demonstrated between the writers on the basis of the enlarged loops, with a correct classification rate superior to 90%, whatever the letter (a, d, o or q). A classification of the enlarged loops in their corresponding writer was then possible. On the contrary, when comparing the enlarged loops to the small ones, almost one half of the enlarged loops were allocated to a wrong writer. Shape invariance was thus not supported for this particular application. Consequently, when comparing documents with a different writing size, differences in loops shape should be interpreted cautiously because they may be due to a different writer, but they may also be due to an enlargement of the loops. Therefore, reference material of similar writing size to that of the questioned writing should be requested for the comparison of handwritten loops.

Phylogenomic analysis and expression patterns of large Maf genes in Xenopus tropicalis provide new insights into the functional evolution of the gene family in osteichthyans.

We have performed an exhaustive characterization of the large Maf family of basic leucine zipper transcription factors in vertebrates using the genome data available, and studied the embryonic expression patterns of the four paralogous genes thus identified in Xenopus tropicalis. Our phylogenetic analysis shows that, in osteichthyans, the large Maf family contains four orthology classes, MafA, MafB, c-Maf and Nrl, which have emerged in vertebrates prior to the split between actinopterygians and sarcopterygians. It leads to the unambiguous assignment of the Xenopus laevis XLmaf gene, previously considered a MafA orthologue, to the Nrl class, the identification of the amphibian MafA and c-Maf orthologues and the identification of the zebrafish Nrl gene. The four X. tropicalis paralogues display partially redundant but nevertheless distinct expression patterns in the somites, developing hindbrain, pronephros, ventral blood island and lens. Comparisons with the data available in the mouse, chick and zebrafish show that these large Maf expression territories are highly conserved among osteichthyans but also highlight a number of differences in the timing of large Maf gene expression, the precise extent of some labelled territories and the combinations of paralogues transcribed in some organs. In particular, the availability of robust phylogenies leads to a reinterpretation of previous expression pattern comparisons, suggesting an important part for function shuffling within the gene family in the developing lens. These data highlight the importance of exhaustive characterizations of gene families for comparative analyses of the genetic mechanisms, which control developmental processes in vertebrates.