Dental Age Assessment: a comparison of 4- to 24-year-olds in the United Kingdom and an Australian population

Background.  The physiological age of a person is determined by the degree of maturation of the different tissue systems. Children of the same chronological age (CA) can demonstrate different degrees of maturation. Dental age (DA) is based on the maturation of teeth. Tooth formation is a continuous process, where the developmental stages of the tooth can be sequenced and defined depending on the degree of mineralization. These stages can be visualized on a dental panoramic tomograph (DPT).
Aim.  The aim of this study was to use a new method of Dental Age Assessment (DAA) to compare a United Kingdom (UK) and an Australian (AUS) population.
Design.  The DPTs used are from the archives of the Westmead Centre for Oral Health (Westmead, Australia) and the King's College London Dental Institute. From the preliminary sample of 89 DPTs from each population, 77 were suitable for use as matched pairs. The radiographic technique used was developed by Demirjian and describes eight stages of tooth development. This was used in combination with numerical data derived from a meta-analysis of a single UK subject.
Results.  A significant difference was shown between the CA and DA of the AUS patients. The AUS patients were also shown to have a significant 0.82 years delay in their DA compared to the UK patients. The findings indicate a difference in AUS compared to UK patients. These results indicate the need to develop a reference data set for the AUS population for DAA.
Conclusions.  This research is of significance in a number of clinical disciplines and can also be used to assist in age determination of subjects of unknown birth date to assist in forensic dentistry or social deliberations.     

An unusual pattern of metastases from Merkel cell carcinoma

An unusual case of Merkel cell carcinoma is presented in which the time course to development of nodal and haematogenous metastases was protracted and the predominant site of metastatic disease was small bowel.     

Salivary oestriol in normal and abnormal pregnancies

Summary. Profiles of daily salivary oestriol concentrations throughout the third trimester of pregnancy have been constructed for 14 normal and 11 abnormal pregnancies. Day-to-day variations were significantly higher than those reported for unconjugated oestriol in plasma or serum. A sustained decline in salivary oestriol concentrations was observed in one pregnancy in which intrauterine death occurred. Sustained falls were also observed in two pregnancies in which a healthy infant was born at term. In all other patients a normal salivary oestriol profile correlated with a favourable outcome. Salivary oestriol measurements provide similar information to plasma unconjugated oestriol measurements while offering the advantages of a simple, non-invasive sample collection procedure.     

Differential Expression of Photoreceptor-Specific Proteins During Disease and Degeneration in the Progressive Rod-Cone Degeneration (prcd) Retina

Progressive rod-cone degeneration (prcd) is a late-onset hereditary retinal degeneration characterized by normal development of photoreceptors prior to degeneration and death of visual cells. We reported previously that expression of opsin mRNA and protein decreases prior to visual cell degeneration. To examine the specificity of this reduction, we have used immunocytochemistry to correlate photoreceptor-specific protein expression with visual cell disease progression. Eyes from light-adapted age-matched control andprcd-affected dogs were fixed in paraformaldehyde, embedded in diethylene glycol distearate (DGD) wax, and reacted with antibodies specific to interphotoreceptor retinoid-binding protein (IRBP), S-antigen, opsin, phosducin, γ-phosphodiesterase (γ-PDE), and β₁-transducin. While IRBP expression did not change with disease progression, immunoreactivity to other proteins varied. For S-antigen and opsin, immunoreactivity decreased dramatically with the transition from photoreceptor disease to degeneration; γ-PDE immunolabeling in rods also decreased, but the reduction was less abrupt. However, for two other proteins (phosducin and β₁-transducin), immunoreactivity increased initially and was redistributed (particularly to the rod outer segment) in early disease (stage 1). Our results show that there is a differential expression of photoreceptor-specific proteins with disease and degeneration that is not uniform for all the gene products examined; expression can be decreased, altered in distribution or remain unchanged. It is clear that the decrease of opsin expression described previously is not an isolated phenomenon in the progression ofprcd, but is part of a more generalized degenerative process which eventually culminates in cell death.