Fracture-dislocation of the lunotriquetral coalition.

Bony fusions involving the carpus have a much higher prevalence in blacks relative to whites. This article describes a case of lunotriquetral coalition fracture-dislocation in an African American. This lesion is best treated through open reduction and pin fixation.     

Palatogram Assessment of Maxillary Complete Dentures

Phonetics, esthetics, function, and comfort form the foundation of a successful dental prosthesis. A review of the mechanics of speech as well as common speech problems encountered with a removable maxillary prosthesis are presented. The use of a palatogram to aid the clinician in the assessment and resolution of speech problems associated with a maxillary denture is demonstrated.     

A low cost modification of an old Leksell stereotactic frame to allow CT-guided stereotaxy

The high cost of commercial CT-compatible stereotactic frames has restricted the availability of CT-guided stereotaxy for many neurosurgical centres. However, many of these centres do possess the standard stereotactic frames for projection radiography, of which the old type Leksell frame is probably the most common. We have devised a simple and low-cost modification to an old Leksell frame to allow CT-guided stereotaxy. The nature of the modifications allow complete freedom of positioning of the frame relative to the CT scanner and coordinate transformations can be performed simply and effectively. The modified frame has been used successfully for some 18 months and the modification has now been performed at two centres in the North West Regional Health Authority. We hope this modification will allow many other centres to embark on CT-guided stereotaxy.     

Cross-reactivity of selected compounds in the Abbott TDx cannabinoid assay

Immunoassay procedures, both enzyme immunoassay and radioimmunoassay, continue to be widely used to screen samples for recent marijuana use by analyzing the urine samples for 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (11-nor-delta 9-THC-9-COOH) (the major urinary metabolite of delta 9-tetrahydrocannabinol [delta 9-THC]). Using commercially available immunoassay reagents, the cross-reactivity of the antiserum utilized in Abbott's TDx cannabinoid assay (a fluorescence polarization immunoassay) was evaluated. This cross-reactivity was evaluated against a group of cannabinoids and noncannabinoid phenolic constituents of Cannabis, some cannabinoid metabolites, and other agents that appear in normal urine samples. In general, the antiserum was equally reactive toward 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid, its glucuronide, and the corresponding delta 8-isomer, which was the acid moiety utilized in standards and controls of the assay prior to January, 1990. Reduced binding to the antiserum was observed with hydroxylated derivatives of delta 9- and delta 8-THC, and the other cannabinoids, in general, exhibited limited binding potentials toward the antibody. For the noncannabinoid constituents, no binding was observed at the highest concentrations evaluated (40 mg/L).     

Sucrose-dependent accumulation of oral streptococci and their adhesion-defective mutants on saliva-coated hydroxyapatite

The adhesion and accumulation of oral streptococci on saliva-coated hydroxyapatite was examined in strains representing species that appear in initial plaque ( Streptococcus sanguise FC1 and Streptococcus oralis C5) and in more mature plaque ( Streptococcus gordonii G9B). Washed cells of strains FC1 and C5 did not attach better to saliva-coated hydroxyapatite than did strain G9B, suggesting that the degree of initial adhesiveness does not alone account for the temporal appearance of these bacteria in dental plaque. Growing cells of each strain were also examined for their ability to accumulate on saliva-coated hydroxyapatite. The addition of sucrose to the medium promoted the accumulation of strain G9B more than it promoted the accumulation of strains FC1 and C5. Sucrose also enhanced the accumulation of adhesion-defective mutants of each strain to levels similar to those of the respective parent strains. These results suggest that sucrose-dependent accumulation may facilitate the colonization of the tooth surface by these species of oral streptococci when adhesion is limited by reduced bacterial adhesiveness or limited pellicle-binding sites.     

Do aluminium and/or glutamate induce Alzheimer PHF-like formation? An electron microscopic study

Paired helical filaments (PHFs) constitute the majority of filaments in neurofibrillary tangles (NFTs), an Alzheimer's disease (AD) characteristic. PHFs consists of two filaments helically twisted around one another in a regular pattern. The effects of possible PHF-inducing candidates, namely aluminium and glutamate, were observed at the ultrastructural level in this investigation. Rat cerebral explants were exposed to aluminium, citric acid and glutamate singly or combined from 7–12 days in vitro (DIV), while control explants remained in basal medium. On 12 DIV, explants were processed for EM. Three–four EM explants were serially sectioned per condition. Ten 60 nm sections from five systematically sampled areas per explant were collected. One section was randomly chosen per sampled area and all neurons within it observed at 81 200– to record the presence of accumulations of curved filaments (CFs), straight filaments (SFs) or PHFs. Using stereological methods, absolute numbers and the percentage incidence of CFs and SFs were calculated. A significant increase in the frequency of neurons containing CF aggregations in aluminium explants compared to glutamate explants was found. There were no significant differences between conditions for neurons containing SF accumulations. Possible PHFs were observed in one aluminium/glutamate-treated explant. These results suggest that aluminium alone can cause significant formation of accumulations of C- or S-shaped CFs, some of which are double-stranded and twisted around one another regularly. However, structures that were possibly PHF-like were only observed in one aluminium-treated explant, thus making it premature to draw an association between aluminium and the induction of AD-like pathology.     

The Future Detection and Prevention of Institutional Abuse: Giving Children a Chance to Participate in Research

The involvement of children in research studies is historically fraught with difficulties. Experiments on children without their consent or knowledge have been carried out in the past and thus the need for stringent ethical control is undoubtedly necessary. However this paper argues that the need to protect children from unethical research has somehow become entwined in the web of secrecy that surrounds the very nature of child abuse. In the name of 'protection' are children in danger of not having their voice heard?

In the foreword to 'Listening to Children' (Alderson, 1995) Roger Singleton writes, 'much research is carried out on and about children, but seldom with children. Children themselves are often strangely silent'. This paper draws on recent literature on the institutional abuse of young people in residential care and the lack of voice that those abused in residential care have traditionally had, suggesting that their silence is not 'strange' but perhaps contrived.

This paper does not repeat the work of Alderson (1995) and make suggestions as to how research with children may best be carried out, but seeks to address the issues in relation to research with children who are in institutions.     

Further characterization of morphologically defined typical and atypical CLL: a clinical, immunophenotypic, cytogenetic and prognostic study on 390 cases

We analysed a group of 390 patients, diagnosed with chronic lymphocytic leukaemia (CLL). Cases were subclassified as morphologically typical and atypical CLL according to the criteria of the FAB proposal. Typical CLL cases were mostly diagnosed at a low-risk stage (Binet A/Rai 0), required no immediate treatment and expected a long survival; atypical CLL cases mostly presented at a more advanced risk stage (Binet B/Rai I–II), usually required immediate treatment and their survival was shorter. Moreover, clinical staging was of prognostic significance in typical but not in atypical cases.   In typical CLL, del(11q) was the most common chromosomal abnormality (21%) whereas in atypical CLL trisomy 12 was found in about 65% of the cases documented with an abnormal karyotype. Although chromosomal abnormalities were associated with a poor survival in typical CLL, they are of no prognostic significance in atypical CLL.   Based on these data, we conclude that subtyping CLL by morphology enables the identification of two groups of cases, each characterized by a specific clinical presentation, different cytogenetic abnormalities and prognostic parameters. We speculate that these two groups may represent two related, but different, diseases with different prognostic parameters and a different survival.