The definitions of three-dimensional landmarks on the human face: an interdisciplinary view.

The analysis of shape is a key part of anatomical research and in the large majority of cases landmarks provide a standard starting point. However, while the technology of image capture has developed rapidly and in particular three-dimensional imaging is widely available, the definitions of anatomical landmarks remain rooted in their two-dimensional origins. In the important case of the human face, standard definitions often require careful orientation of the subject. This paper considers the definitions of facial landmarks from an interdisciplinary perspective, including biological and clinical motivations, issues associated with imaging and subsequent analysis, and the mathematical definition of surface shape using differential geometry. This last perspective provides a route to definitions of landmarks based on surface curvature, often making use of ridge and valley curves, which is genuinely three-dimensional and is independent of orientation. Specific definitions based on curvature are proposed. These are evaluated, along with traditional definitions, in a study that uses a hierarchical (random effects) model to estimate the error variation that is present at several different levels within the image capture process. The estimates of variation at these different levels are of interest in their own right but, in addition, evidence is provided that variation is reduced at the observer level when the new landmark definitions are used.

Psychological status as a function of residual scarring and facial asymmetry after surgical repair of cleft lip and palate.

Objective : Objective measure of scarring and three-dimensional (3D) facial asymmetry after surgical correction of unilateral cleft lip (UCL) and unilateral cleft lip (UCLP). It was hypothesized that the degree of scarring or asymmetry would be correlated with poorer psychological function. Design : In a cross-sectional design, children underwent 3D imaging of the face and completed standardized assessments of self-esteem, depression, and state and trait anxiety. Parents rated children's adjustment with a standard scale. Setting : Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences. Patients : Fifty-one children aged 10 years with UCLP and 43 with UCL were recruited from the cohort treated with the surgical protocol of the CLEFTSIS managed clinical network in Scotland. Methods : Objective assessment to determine the luminance and redness of the scar and facial asymmetry. Depression, anxiety, and a self-esteem assessment battery were used for the psychological analysis. Results : Cleft cases showed superior psychological adjustment when compared with normative data. Prevalence of depression matched the population norm. The visibility of the scar (luminance ratio) was significantly correlated with lower self-esteem and higher trait anxiety in UCLP children (P  =  .004). Similar but nonsignificant trends were seen in the UCL group. Parental ratings of poorer adjustment also correlated with greater luminance of the scar. Conclusions : The objectively defined degree of postoperative cleft scarring was associated with subclinical symptoms of anxiety, depression, and low self-esteem.

Vaccines with aluminum-containing adjuvants: optimizing vaccine efficacy and thermal stability.

Aluminum-containing adjuvants have been used to enhance the immune response against killed, inactivated, and subunit antigens for more than seven decades. Nevertheless, we are only beginning to gain important insight as to what may be some very fundamental parameters for optimizing their use. For example, there is evidence that the conventional approach of maximizing antigen binding (amount and/or strength) may not result in an optimal immune response. Adsorption of antigen onto the adjuvant has recently been suggested to decrease the thermal stability of some antigens; however, whether adsorption-induced alterations to the structure and/or stability of the antigen have consequences for the elicited immune response is unclear. Finally, the thermal stability of vaccines with aluminum-containing adjuvants is not robust. Optimizing the stability of these vaccines requires an understanding of the freeze sensitivity of the adjuvant, freeze and heat sensitivity of the antigen in the presence of the adjuvant, and perhaps most important, how (or whether) various approaches to formulation can be used to address these instabilities. This review attempts to summarize recent findings regarding issues that may dictate the success of vaccines with aluminum-containing adjuvants.

RNA expression microarrays (REMs), a high-throughput method to measure differences in gene expression in diverse biological samples.

We have developed RNA expression microarrays (REMs), in which each spot on a glass support is composed of a population of cDNAs synthesized from a cell or tissue sample. We used simultaneous hybridization with test and reference (housekeeping) genes to calculate an expression ratio based on normalization with the endogenous reference gene. A test REM containing artificial mixtures of liver cDNA and dilutions of the bacterial LysA gene cDNA demonstrated the feasibility of detecting transcripts at a sensitivity of four copies of LysA mRNA per liver cell equivalent. Furthermore, LysA cDNA detection varied linearly across a standard curve that matched the sensitivity of quantitative real-time PCR. In REMs with real samples, we detected organ-specific expression of albumin, Hnf-4 and Igfbp-1, in a set of mouse organ cDNA populations and c-Myc expression in tumor samples in paired tumor/normal tissue cDNA samples. REMs extend the use of classic microarrays in that a single REM can contain cDNAs from hundreds to thousands of cell or tissue samples each representing a specific physiological or pathophysiological state. REMs will extend the analysis of valuable samples by providing a common broad based platform for their analysis and will promote research aimed at defining gene functions, by broadening our understanding of their expression patterns in health and disease.

Suppression subtractive hybridization.

Suppression subtractive hybridization (SSH) is a widely used method for separating DNA molecules that distinguish two closely related DNA samples. Two of the main SSH applications are cDNA subtraction and genomic DNA subtraction. In fact, SSH is one of the most powerful and popular methods for generating subtracted cDNA or genomic DNA libraries. The SSH method is based on a suppression PCR effect and combines normalization and subtraction in a single procedure. The normalization step equalizes the abundance of DNA fragments within the target population, and the subtraction step excludes sequences that are common to the populations being compared. This dramatically increases the probability of obtaining low-abundance differentially expressed cDNA or genomic DNA fragments, and simplifies analysis of the subtracted library. In our hands, the SSH technique has enriched over 1000-fold for rare sequences in a single round of subtractive hybridization.