Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein

Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp(-/-) mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp(-/-) mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp(-/-) mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp(-/-) mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified in endochondral ossification in the cranial base, and craniofacial morphology was unaffected in Bsp(-/-) mice. These analyses confirm a critical role for BSP in processes of cementogenesis and intramembranous ossification of craniofacial bone, whereas endochondral ossification in the cranial base was minimally affected and dentinogenesis was normal in Bsp(-/-) molar teeth. Dissimilar effects of loss of BSP on mineralization of dental and craniofacial tissues suggest local differences in the role of BSP and/or yet to be defined interactions with site-specific factors.

Epigenotype-phenotype correlations in Silver-Russell syndrome

Background

Silver–Russell syndrome (SRS) is characterised by intrauterine growth restriction, poor postnatal growth, relative macrocephaly, triangular face and asymmetry. Maternal uniparental disomy (mUPD) of chromosome 7 and hypomethylation of the imprinting control region (ICR) 1 on chromosome 11p15 are found in 5–10% and up to 60% of patients with SRS, respectively. As many features are non-specific, diagnosis of SRS remains difficult. Studies of patients in whom the molecular diagnosis is confirmed therefore provide valuable clinical information on the condition.

Methods

A detailed, prospective study of 64 patients with mUPD7 (n=20) or ICR1 hypomethylation (n=44) was undertaken.

Results and conclusions

The considerable overlap in clinical phenotype makes it difficult to distinguish these two molecular subgroups reliably. ICR1 hypomethylation was more likely to be scored as ‘classical’ SRS. Asymmetry, fifth finger clinodactyly and congenital anomalies were more commonly seen with ICR1 hypomethylation, whereas learning difficulties and referral for speech therapy were more likely with mUPD7. Myoclonus-dystonia has been reported previously in one mUPD7 patient. The authors report mild movement disorders in three further cases. No correlation was found between clinical severity and level of ICR1 hypomethylation. Use of assisted reproductive technology in association with ICR1 hypomethylation seems increased compared with the general population. ICR1 hypomethylation was also observed in affected siblings, although recurrence risk remains low in the majority of cases. Overall, a wide range of severity was observed, particularly with ICR1 hypomethylation. A low threshold for investigation of patients with features suggestive, but not typical, of SRS is therefore recommended.

EEC (Ectrodactyly, Ectodermal dysplasia, Clefting) syndrome: heterozygous mutation in the p63 gene (R279H) and DNA-based prenatal diagnosis

BACKGROUND

Germline mis-sense mutations in the DNA-binding domain of the p63 gene have recently been established as the molecular basis for the autosomal dominant EEC (Ectrodactyly, Ectodermal dysplasia, Clefting) syndrome.

OBJECTIVES

To examine genomic DNA from a 36-year-old woman, her 58-year-old father and her 11-year-old son, all with the EEC syndrome, to determine the inherent p63 mutation and, after genetic counselling, to use knowledge of the mutation to undertake a first-trimester DNA-based prenatal diagnosis in a subsequent pregnancy.

METHODS

Fetal DNA was extracted from chorionic villi and used to amplify exon 7 of p63 containing the potential mutation. Direct sequencing and restriction endonuclease digestion (loss of AciI site on mutant allele) were used for DNA-based prenatal diagnosis.

RESULTS

We identified a heterozygous arginine to histidine p63 mutation, R279H, in all three affected individuals. Prenatal diagnosis demonstrated a homozygous wild-type sequence predicting an unaffected child: a healthy boy was subsequently born at full-term.

CONCLUSIONS

These data expand the p63 gene mutation database and provide the first example of a DNA-based prenatal test in this ectodermal dysplasia syndrome.

Mass spectrometry screening of combinatorial mixtures, correlation of measured and predicted electrospray ionization spectra

Methodology was developed to afford rapid characterization of multicomponent mixtures of small organic molecules prepared by split-and-mix combinatorial synthesis. This methodology involved the use of liquid chromatography mass spectrometry (LC/MS) combined with correlation analysis of measured versus predicted electrospray ionization mass spectra. Low-resolution mass spectra of complex mixtures revealed predictable patterns that confirm library products, assisted in identifying chemical synthesis errors, and assessed overall library integrity. In general, equal signal intensities were observed for most combinatorial mixture components, indicating that differences in electrospray ionization efficiency was not a major limitation to this approach. High-throughput data processing programs and informatics tools were used to speed data analysis and to simplify the presentation of the library characterization results. This approach has been used to characterize combinatorial libraries that were synthesized for a variety of drug-discovery programs. Examples are shown for library formats of 1, 40, 66, 280, and 400 component(s)/well. The applicability of this approach to large combinatorial mixtures should allow direct characterization of massive combinatorial libraries.

Modification of the tear function index and its use in the diagnosis of Sjögren's syndrome

BACKGROUND

The tear function index (TFI) has been shown to be of value in the diagnosis of patients suffering from Sjögren's syndrome. It is dependent, however, on introducing into the conjunctival fornix the correct concentration of fluorescein in at least one and a half times the normal tear volume. The stimulus and effect of this added volume on the tear dynamics is likely to vary between individuals. These factors, together with the method of performing the test, limit its general applicability.

AIM

To devise a method of performing the TFI with less variability and more general applicability. To present a theoretical and in vitro assessment of the dynamics of the TFI.

METHOD

The study was divided into three parts. The first part was to compare the results obtained using a prepared strip containing 1.3 microl of 0.5% fluorescein with the introduction of the same amount of fluorescein as a drop. The second part was to compare the results obtained with prepared strips with the standard method of performing the TFI, both with and without topical anaesthetic. The third part was an in vitro study of the rate of flow of graded volumes on a filter paper strip. 42 subjects with a diagnosis of Sjögren's syndrome according to the European criteria and 126 without Sjögren's syndrome were included.

RESULTS

There was no significant difference between the results obtained with a prepared strip and the introduction of 1.3 microl into the eye before performing the Schirmer's test and TFI (0.1<p<0.93). There was, likewise, no significant difference between using the prepared strips and the standard method of performing the TFI (0.36<p<0.93). There was, however, less interocular difference (p=0.01) and variability (p=0.001) using the prepared strips than using a drop of fluorescein. Patients with Sjögren's syndrome had mean TFIs of 11.7 and 8.61 with upper 95% confidence values of 15 and 12 without and with topical anaesthetic, respectively. The theoretical calculation of the TFI was similar to the observed values. The in vitro results allow the filter paper to be removed from the eye at any interval and to estimate the volume of tears that the filter paper was in contact with.

CONCLUSION

The proposed method of performing the TFI is easy to perform, reliable, and therefore has general applicability for primary care and general practitioners. It allows the rapid identification of subjects who may be suffering from Sjögren's syndrome.

Measuring the self-esteem of adolescents with mental health problems: theory meets practice

Occupational therapists frequently address the self-esteem of young clients despite little empirical evidence that the clients have low self-esteem to begin with, and that occupational therapy intervention is effective in addressing self-esteem. This article examines the self-esteem of 39 adolescents with mental health problems referred to a pre-vocational programme in an effort to compare clinical practice with empirical findings. The Self-Perception Profile for Adolescents and the Importance Rating Scale for Adolescents are employed to compare the self-esteem of the adolescents with mental health problems with the normative sample, prior to (n = 39) and upon completion of the pre-vocational programme (n = 14). Results indicate no difference between the two groups' self-esteem and no change in self-esteem scores following participation in the pre-vocational programme. Global self-esteem is significantly correlated with physical appearance and behavioural conduct (n = 39). Competence-importance discrepancy scores are significantly related to global self-esteem (n = 14). This finding supports the theory that it is the domain of self-concept which is low and important to the adolescent which will influence his/her self-esteem. These results are consistent with previous studies. Possible explanations for the discrepancy between clinical perceptions and objective findings are discussed. Implications for practice are presented.

Pitfalls in the management of a child with mild haemophilia A and a traumatic hyphaema

A 12-year-old boy presented with a traumatic hyphaema that failed to settle with the standard treatment. Subsequent investigation showed that despite a normal APTT, he had a low factor VIII:C. Treatment with DDAVP precipitated further bleeding despite correction of the fVIII:C to normal, possibly caused by the vasodilation induced by the therapy. Bleeding was effectively treated with recombinant fVIII concentrate. DDAVP may be contraindicated in mild Haemophilia and von Willebrand patients for treatment of traumatic hyphaema.

A framework for integrated quality improvement

The importance of maintaining and improving quality is well understood in most health care organizations. This work becomes more challenging as internal and external conditions rapidly change. A quality improvement framework was developed to help clinicians and administrators organize intergrated, multifaceted quality programs that have the flexibility necessary for success in today's fast-paced health care environment.

A therapist's guide to children's self-esteem

The term self-esteem is frequently used by occupational therapists and other health care professionals who work with children. There are differing interpretations as to what this term actually means. In this article, we use Susan Harter's model of self-esteem to define the nature of self-esteem and apply it to clinical practice. We outline the developmental characteristics important to consider when addressing the self-esteem of young children, such as the findings that young children's self-esteem is often more related to their perceptions of parental acceptance than perceptions of competence and that children are generally unable to accurately verbalize their level of self-esteem until 8 years of age. Specific implications for occupational therapy evaluation include whether the use of self-report or observer-report measures is preferable and whether self-esteem or self-concept should be measured. We discuss when to address self-esteem and which dimensions of self-esteem should be treated. The dimensions of self-esteem that are identified as low during the evaluation and that the child perceives to be important are addressed. The reevaluation issue of what specifically should be measured after intervention is also discussed. For example, it is recommended that the reevaluation instrument be sensitive to the domains of self-concept targeted for intervention.

Motor problems in children with developmental coordination disorder: review of the literature

Occupational therapists frequently work with children with developmental coordination disorder (DCD) in hopes of enhancing their occupational performance. There is debate among researchers and health care professionals about whether the motor coordination problems experienced by children with DCD have a physiological basis or whether they are the result of a developmental delay. Even among researchers who agree that these difficulties are of physiological origin, there is a lack of consensus as to whether these motor problems are multisensory or unisensory. This article focuses on the physiological explanation, presents a review of the literature on the possible physiological origins of motor coordination problems in children with DCD, and shows that the current literature on the physiological basis of DCD requires more empirical evidence to substantiate either multisensory or unisensory theories of motor dysfunction in children with DCD. The debate over the nature of motor problems in children with DCD has two implications for occupational therapists: that there is no one way to treat these children and that the cause of the difficulty varies from child to child.

Intraspecific variation and sexual dimorphism in cranial and dental variables among higher primates and their bearing on the hominid fossil record

The extent and nature of dental and cranial sexual dimorphisms in extant hominoids have been investigated using reliably sexed samples of Homo sapiens (n = 75), Pan troglodytes (n = 51), Gorilla gorilla (n = 64) and Pongo pygmaeus (n = 43). Seventy nine measurements (35 dental, 16 mandibular and 28 cranial) formed the basis of the study. The patterns of mean differences and dispersions between the taxa were compared across the anatomical regions and the group structures of the separate sex samples were analysed using multivariate (PCA and CVA) analysis. Within and between group variations were compared across the taxa to investigate whether any variables were consistently effective sex or taxonomic discriminators. The study confirmed that there were differences in degree and pattern of sexual dimorphism between the extant higher primates, but the results did not substantiate the distribution of patterns as suggested by Oxnard et al. (1985); in particular there was no evidence of the dispersion differences noted by those authors. There were sufficient consistencies in the behaviour of variables across the four taxa to suggest that all canine dimensions, postcanine crown buccolingual dimensions and mandibular and cranial breadths are generally good sex discriminators, whereas some incisor dimensions, postcanine crown mesiodistal dimensions and facial heights are more effective at discriminating between the four extant taxa included in this study.

Lichen nitidus. A study of forty-three cases

Among forty-three cases of lichen nitidus studied, twenty-one patients were Caucasian, twenty-one were Negro, and one was Spanish-American, ranging in age from five to fifty-eight years. The arm, forearm, trunk, and genitalia were sites most commonly involved. Clinically, the eruption usually appeared as tiny papules. Histologically, the papules showed a parakeratotoic "cap," epidermal atrophy, liquefaction degeneration of the basal layer, and a dermal infiltrate of lymphocytes, epithelioid cells, and sometimes giant cells.