Keratoconus Prevalence Among High School Students in New Zealand.

PURPOSE: To determine the prevalence of keratoconus among high school students in Wellington, New Zealand. METHOD: The Wellington Keratoconus Study was a population-based prospective cross-sectional study of 2 cohorts in Wellington: cohort 1 (year 9 students, mean age 13.9 years) and cohort 2 (year 11 students, mean age 15.5 years). RESULTS: A total of 1916 students with a mean age of 14.6 years participated from 20 schools in the region. Keratoconus was found in 1:191 (0.52%) participants overall and in 1:45 (2.25%) Maori participants. Pentacam mean Kmax of 48.7 diopters (D) (cohort 1, 45.5 D; cohort 2, 49.9 D), thinnest pachymetry of 494.05 µm (cohort 1, 479.0 µm; cohort 2, 499.5 µm), posterior elevation at the thinnest point of 23.4 (cohort 1, 15.2; cohort 2, 26.6), Belin/Ambrosio enhanced ectasia display overall D value of 4.30 (cohort 1, 3.2; cohort 2, 4.7) were noted in participants with keratoconus. In those with keratoconus, 8 of 10 had visual impairment of 0.2 Logarithm of the Minimum Angle of Resolution (LogMAR) or worse in the better eye; 7 of 10 did not use visual aids; 7 of 10 had atopy; and 6 of 10 were from a low school decile. In those without keratoconus, 43.8% had atopy. CONCLUSIONS: Keratoconus may affect up to 1 in 191 New Zealand adolescents and 1 in 45 Maori adolescents. Keratoconus appeared to be associated with Maori ethnicity, atopy, lower school decile, visual impairment, and the underutilization of visual aids. Nationwide screening programs may have a role in reducing the burden of disease associated with keratoconus.

Lack of prognostic effect of carbonic anhydrase-9, hypoxia inducible factor-1α and bcl-2 in 286 patients with early squamous cell carcinoma of the glottic larynx treated with radiotherapy.

AIMS: To evaluate the prognostic significance of potential tumour markers of hypoxia and apoptosis in early squamous cell carcinoma of the glottic larynx managed with radiotherapy. MATERIALS AND METHODS: In total, 382 patients with T1 and T2 squamous cell carcinoma of the glottic larynx (vocal cords) received radical radiotherapy (50-55 Gy, in 16 fractions in 98% of cases). Pre-treatment haemoglobin was available for 328 patients; biopsy samples were available for 286. Immunohistochemistry was carried out for carbonic anhydrase-9 (CA-9), hypoxia inducible factor-1α (HIF-1α) and Bcl-2. RESULTS: At 5 years, locoregional control was achieved in 88.2%, cancer-specific survival in 95.0% and overall survival in 78.7%. Adverse prognostic factors for locoregional tumour recurrence were pre-treatment haemoglobin <13.0 g/dl (P = 0.035, Log rank test; sensitivity 0.28, specificity 0.84) and stage T2 rather than T1 (P = 0.002). The effect of haemoglobin level on locoregional control was not significant when stratified by the median of 14.2 g/dl (P = 0.43) or as a continuous variable (P = 0.59). High CA-9 (P = 0.11), HIF-1α (P = 0.67) and Bcl-2 (P = 0.77) expression had no prognostic significance. CONCLUSIONS: High CA-9, HIF-1α and Bcl-2 do not add to the prognostic significance of tumour stage and lower haemoglobin in predicting failure of local control in early glottic larynx squamous cell carcinoma managed with radiotherapy. The effect of haemoglobin was not strong enough to be useful as a prognostic biomarker.

Comparison of two clinical Bleb grading systems.

PURPOSE: To evaluate 2 recently described grading systems for clinical grading of filtering surgery blebs: the Moorfields Bleb Grading System (MBGS) and the Indiana Bleb Appearance Grading Scale (IBAGS). DESIGN: Observational comparative study. PARTICIPANTS: Twenty-four glaucoma filtering blebs in 24 eyes of 17 patients. METHODS: Three observers in a prospective agreement study compared MBGS with IBAGS during slit-lamp examination. MAIN OUTCOME MEASURES: Comparison analyses were performed, including agreement, repeatability, and intraclass correlation coefficient (ICC). RESULTS: A wide range of bleb characteristics was represented in the cohort. Acceptable levels of intrasystem agreement were found in both systems: for IBAGS, overall agreement at the 0.5- and 1.0-unit levels were 80.6% and 97.6%, respectively, and for MBGS, these were 78.4% and 97.4% for morphologic and vascularity indices. Repeatability coefficients ranged from 0.5 to 1.4 for MBGS and 0.8 to 1.2 for IBAGS. The ICC values in the MBGS ranged from 0.18 to 0.72 for single measures and 0.39 to 0.88 for average measures. For IBAGS, the single-measure ICC values were between 0.06 and 0.53, and the average-measure ICC values were between 0.16 and 0.77. The MBGS ICC values for bleb size were higher than for IBAGS. CONCLUSIONS: Both methods are reproducible clinically and had generally high levels of interobserver agreement. Both have minor deficiencies that should be amenable to improvement. The MBGS performed similarly to the IBAGS for reproducibility, had higher ICC values for morphologic features, and captured extra vascularity data with probable clinical implications.

The influence of fluoride exposure on dentin mineralization using an in vitro organ culture model.

This study aimed to characterize fluoride-induced alterations in dentin mineralization within a dentin-pulp organ culture system. Tooth sections derived from male Wistar rat incisors were cultured in Trowel-type culture for 14 days, in the presence of 0 mM, 1 mM, 3 mM and 6 mM sodium fluoride. Tooth sections were processed and analyzed for uptake of fluoride, its subsequent effect on dentin mineralization by tetracycline hydrochloride incorporation and mineral composition, expressed as calcium/phosphorous (Ca/P) ratios. Tetracycline hydrochloride incorporation was demonstrated to decrease with increased fluoride exposure, accompanied by significant increases in both Ca/P ratios and fluoride incorporation. These findings provide further evidence that the established alterations in dentin formation during fluorosis are a consequence of disruption to the mineralization process, and provide a model system with which to investigate further the potential role the extracellular matrix plays in inducing the apparent changes in mineral composition.

Molecular interaction of recombinant decorin and biglycan with type I collagen influences crystal growth.

This study has investigated the interaction of recombinant chondroitin sulphate (CS)-substituted decorin and biglycan on collagen fibrillogenesis, their interaction with hydroxyapatite (HAP), and HAP-induced crystal growth. The core proteins of the recombinant decorin and biglycan were obtained following chondroitinase ABC digestion and their influence on the above physical mechanisms were investigated in parallel. CS-decorin promoted collagen fibrillogenesis, with the interaction mediated principally through the core protein. Both decorin and biglycan demonstrated a strong association for HAP, predominately facilitated through the glycosaminoglycan chains. HAP-induced crystal growth was inhibited by decorin and biglycan, although the degree of inhibition was reduced when these proteoglycans were complexed with type I collagen. Thus, this study has highlighted potentially differing roles for decorin and biglycan, as both promoters and inhibitors in the regulation of the mineralization process.

Changing profiles of proteoglycans in the transition of predentine to dentine.

Proteoglycans and their constituent glycosaminoglycans have been proposed to play important roles in matrix mediated formation of mineralised tissues, such as dentine. This study has examined the changing profile of proteoglycan species during the transition of unmineralised predentine to mineralised dentine. Three-week-old calves teeth were collected and proteoglycans purified from the predentine, the predentine/dentine interface and dentine. Decorin and biglycan, together with related degradation products, were identified in the predentine fraction, alongside degradation products of versican, indicating metabolism of the proteoglycan components within this tissue. Decorin and biglycan were also identified as major proteoglycan species within extracts from the predentine/dentine interface and dentine. Analysis of the glycosaminoglycan constituents within each fraction demonstrated significant changes in their composition. Predentine contained a high proportion of dermatan sulfate (DS) (51.5%), with chondroitin sulfate (CS) (17.8%) and hyaluronan (HA) (30.7%) additionally identified. Within the predentine/dentine interface the proportion of CS increased greatly (62.5%), with corresponding decrease in the proportion of DS (21.4%) and HA (16.1%) also evident. CS only was identifiable within the dentine matrix. A four-fold increase in the level of sulfation was identified for glycosaminoglycans extracted from the predentine/dentine interface compared with the predentine and dentine fraction. The ratio of DeltaDi4S:DeltaDi6S was higher for glycosaminoglycans isolated from the predentine fraction. Glycosaminoglycans extracted from the dentine fraction possessed longer chain lengths than those present in the predentine and predentine/dentine fractions. The results indicate that the proteoglycans within each fraction undergo subtle structural modification, particularly at the onset of mineralisation, indicating an active involvement of these macromolecules in the overall mineralisation process.

The influence of fluoride on the cellular morphology and synthetic activity of the rat dentine-pulp complex in vitro.

Exposure to high fluoride concentrations in the immediate environment of the tissue is recognized to result in the post-translational modification of non-collagenous dentine extracellular matrix (ECM) components, potentially altering dentine mineralization. However, less is known about the effects of fluoride exposure on the morphology or metabolism of the cells associated with the dentine-pulp complex. This study examined the effects of fluoride exposure at defined concentrations on the cellular morphology and ECM synthetic activities of odontoblasts and pulpal fibroblasts by the culture of tooth sections from male Wistar rat incisors in Trowel-type cultures for up to 14 days, in the presence and absence of 6mM sodium fluoride. Histomorphometric analysis of the dentine-pulp complex of sodium fluoride-exposed tooth sections demonstrated no obvious gross morphological differences with respect to the odontoblasts and pulpal fibroblasts throughout the 14-day culture period, in comparison with unexposed tooth sections. No significant differences in odontoblast and pulpal fibroblast cell numbers were determined in the absence and presence of fluoride. Image analysis examination of odontoblast cytoplasmic:nuclear (C/N) ratios also showed no significant differences in fluoride-exposed and unexposed tooth sections, although reductions in the C/N ratios of pulpal fibroblasts were evident in fluoride-exposed sections at days 10 and 14. No significant differences in predentine width were observed in fluoride-exposed and unexposed tooth sections over the 14-day culture period. Autoradiography following [3H]proline incorporation into the dentine-pulp complex demonstrated inhibition of collagen synthesis, particularly by the odontoblasts in tooth sections exposed to 6mM sodium fluoride. These findings, in association with those from previous studies, imply that dentine ECM alterations may contribute to the altered mineralization of dentine during fluorosis, rather than secretory-related changes in odontoblast morphology.

Temperospatial expression of matrix metalloproteinases 1, 2, 3, and 9 during early tooth development.

Odontogenesis involves a complex series of processes including epithelial-mesenchymal interactions, morphogenesis, differentiation, fibrillogenesis, and mineralization. Extracellular (ECM) remodeling plays a critical role in the rapid morphological changes that accompany these events. It is proposed that matrix metalloproteinases (MMPs) participate in the remodeling of tooth-specific matrices that accompanies the developmental events. MMPs are zinc-requiring endopeptidases that are centrally involved in the controlled turnover of ECM components and are key to a varied range of developmental processes. Thus, the aim of this study was to examine the expression of MMPs 1, 2, 3, and 9 within the developing tooth germ of Wistar rats, using immunohistochemical localisation. During the bud stage, MMPs 1, 2, 3, and 9 were expressed within both epithelial and mesenchymal cells. Later on, during the cap stage, differential expression was observed; of note was the expression of MMP 3 within the enamel knot. This study reports the temperospatial expression of MMPs 1, 2, 3, and 9 during early tooth development, and points to them having a key role during this important developmental period.

Immunoelectron microscopic visualization of pro- and secreted forms of decorin and biglycan in the predentin and during dentin formation in the rat incisor.

Using antibodies raised against the proform and fully processed (secreted) forms of the proteoglycans decorin and biglycan, combined with gold electron immunohistochemistry, we observed in the incisors of five Sprague-Dawley rats that the proforms were mostly located in the cell bodies of odontoblasts, with a presence reduced to one-third or one-fourth in the processes. Proforms, also present in the extracellular matrix, were uniformly distributed throughout predentin, with higher labeling for probiglycan than pro-decorin. Both were present in lesser amounts in metadentin and dentin. With respect to the secreted form, grain density was at a constant level for biglycan in predentin and dentin, whereas a gradient was detected for decorin, the grain density being increased three times in the distal predentin. Although decorin labeling was diminished in metadentin, staining in circumpulpal dentin was similar to that found in distal predentin. We have previously reported a reverse gradient for chondroitin sulfate/dermatan sulfate distribution. To reconcile these diverging data, our hypothesis is that enzymatic proteolytic cleavage may remove the glycosylated N-terminal-containing region, resulting in a non- proteoglycan form of the molecule. Although substantial differences in distribution were apparent between the two proteoglycans, increasing interactions between proteoglycans and collagen, facilitated by the cleavage and loss of the N-terminal glycosaminoglycan chain region in the distal predentin, may be a prerequisite for dentin mineralization.

Comparison of acute swelling and function in subjects with lateral ankle injury.

STUDY DESIGN: Prospective correlational study involving a convenience sample. OBJECTIVES: To investigate the relationships among figure-of-eight girth measurements and functional level in patients with acute lateral ankle sprains to determine the appropriate use of these clinical measures. BACKGROUND: Research has shown that subjective scales of perceived athletic ability and measurements of swelling are useful in assessing clinical improvement following an acute ankle sprain; however, the relationship between ankle swelling and level of function is not known. METHODS AND MEASURES: Twenty-nine subjects (20 men, 9 women) varying in age from 18-59 years of age (mean age, 30.8 +/- 11.37) with acute lateral ankle sprains were included in this study. Each subject was evaluated by 1 of 3 raters for ankle girth, weight-bearing status, and functional level as determined by a modified Ankle Osteoarthritis Scale (AOS) and the Foot and Ankle Ability Index (FAAI). This study also investigated the relationship between these measures and the sport subscale of the FAAI (FAAI sport). This is an 8-item subscale which includes questions on running, jumping, landing, quick starts and stops, cutting or lateral movements, low impact activities, ability to perform an activity with normal technique, and ability to participate in desired sports. RESULTS: No significant correlations were found between figure-of-eight girth measurements and functional level. However, we did find moderate to good correlations between the FAAI vs. weight-bearing (rho = 0.73), FAAI vs. AOS (rho = -0.79), FAAI sport vs. weight-bearing (rho = 0.68), FAAI vs. FAAI Sport (rho = 0.73), weight-bearing vs. AOS (rho = -0.57), and FAAI Sport vs. AOS (rho = -0.50). CONCLUSIONS: The figure-of-eight method is highly reliable and is appropriate for measuring ankle swelling; however, it does not correlate with functional level as determined by the modified AOS, FAAI, or observed weight-bearing status during gait. Therefore, clinicians should refrain from making assumptions about function based on ankle swelling.

The isolation and detection of non-collagenous proteins from the compact bone of the dinosaur Iguanodon.

This report describes the isolation of guanidinium chloride extractable protein from demineralised bone extracts obtained from the 125-130 mya dinosaur Iguanodon. Protein products were isolated in the Mr. range 5,000-66,000 using SDS-PAGE and represent the first electrophoretically defined proteins isolated from dinosaur tissues. The levels of glycine, aspartate and serine tentatively suggest the presence of phosphoproteins. Hydroxylysine and hydroxyproline were not detected, confirming the presence of non-collagenous material. In addition the absence of ornithine confirmed lack of bacterial contamination. The relatively high level of leucine in the 2MNaCl NaCl fractions together with the abolition of alcian blue reactivity following protease-free chondroitinase digestion suggests the presence of proteoglycans. The study is of interest in describing the early proteins laid down in mineralised tissues for epitactic crystal growth and may provide evidence on evolutionary aspects of bone proteins.

A quantitative study of aromatic amine permeation through protective gloves using amine adsorptive pads.

A quantitative study of aromatic amine permeation through a glove material using Permea-Tec aromatic amine pads, used for the detection of chemical breakthrough of protective clothing, was performed for aniline following the microwave extraction process and gas chromatographic analysis. Aniline exhibited >99% adsorption on the pads at a spiking level of 1.94 mg (1.9 microL). Aniline showed recoveries from 65 to 89% (RSD < or =5.6%) over the range 1.1-1.9 microL (1.12-1.94 mg) of aniline applied to pads. The modified ASTM F739 and direct permeability testing procedures were used to determine breakthrough times for five protective glove materials using aniline as a challenge chemical. Breakthrough times for six protective gloves were determined, ranging from 182 sec to 82 min. The quantitative concentration of aniline on the pads following permeation through the gloves also was determined, ranging from 0.53 to 0.55 mg/cm2 (1.79-1.88 mg/pad).

Long-term psychological and neurological complications of lindane poisoning.

A thin, healthy, partial-vegetarian, white female, who was exposed to three doses of lindane (through the application of Kwell), developed a severe case of long-term lindane poisoning. Review of the literature suggests that her toxicity was so severe because of the repetitive nature of her exposure and the fact that she was partly protein restricted when first exposed. She developed profound central nervous system toxicity, as well as skin and gastrointestinal changes, that persisted for 20 months. She was treated with high doses of Valium. It was noted that every time her Valium was diminished below a critical level, her symptoms tended to recur until she had adequately cleared the lindane from her system. We believe this is the longest term of poisoning reported following exposure to an organochloride insecticide. Her symptoms are well explained by the physiology of these compounds as described in the literature. The case is important, for it represents the longest persistence of symptoms clearly associated with poisoning by the potent gamma isomer of BHC-lindane.

Anxiety and endocrine disease.

It is our goal in this article to review the literature and define those endocrinological diseases that often include anxiety states as part of their initial presentation or as a characteristic symptom seen during their course. Understanding the mechanism by which anxiety develops as a routine part of these neuroendocrinological disorders may help us understand the organic basis of anxiety disorders. Research using new neurochemical, neuroanatomical, and brain imaging techniques may further define the structural and physiological underpinnings of the anxiety disorders.

Relationship between ankle invertor H-reflexes and acute swelling induced by inversion ankle sprain.

STUDY DESIGN: Single group, post-test design using the uninvolved lower extremity as the experimental control. OBJECTIVES: To determine relationships between ankle swelling and flexor digitorum longus and peroneus longus H-reflex amplitude and latency. BACKGROUND: Primary capsuloligamentous injury, neural injury, and joint effusion and swelling may contribute to H-reflex changes following inversion ankle sprain. The relationship between ankle swelling and invertor or evertor H-reflexes has not been reported. METHODS AND MEASURES: Fifteen subjects with acute grade I or II inversion ankle sprains (mean +/- SD) 6.5 +/- 3 days after onset participated in this study. Swelling was estimated using a tape measure and the figure-of-eight girth assessment method. H-reflexes were determined using standard techniques. Paired t-tests were used to compare mean differences in ankle girth (swelling) and ankle invertor or evertor H-reflex amplitude and latency between the involved and uninvolved limbs. Pearson product moment correlations were used to assess relationships between swelling and H-reflex variables. RESULTS: Involved limb ankle girth was increased with respect to the uninvolved limb (1.5 +/- 0.9 cm) and the involved ankle flexor digitorum longus latency was delayed (0.72 +/- 0.7 ms). There was a moderate positive association (r = 0.73) between the latency delay in the involved ankle flexor digitorum longus and swelling. There were no significant differences in H-reflex amplitude and peroneus longus latency between ankles. CONCLUSIONS: Grade I or II inversion sprains and the related swelling appear to delay involved ankle flexor digitorum longus latency to a greater extent than peroneus longus latency. Clinicians need to direct greater attention to the ankle invertors when designing and implementing ankle rehabilitation programs, particularly during the swelling management phase of treatment.

The proteoglycans of human cementum: immunohistochemical localization in healthy, periodontally involved and ageing teeth.

Cementum is believed to play a regulatory role in periodontal regeneration through a variety of macromolecules present in its extracellular matrix (ECM), among which are the proteoglycans (PG). The PG of human cementum have not been fully characterized. This study has used a standard indirect immunoperoxidase technique to investigate the presence and distribution of PG species within the ECM of human cementum. Freshly extracted human permanent teeth were separated into 8 age groups; each group was subdivided to include healthy and periodontally involved teeth, which were then fixed, demineralized and wax-embedded. Sections were incubated with polyclonal antibodies recognizing protein core epitopes in the large chondroitin sulphate PG versican and the small interstitial PG decorin, biglycan, fibromodulin and lumican. Immunoreactivity to versican, decorin, biglycan and lumican was evident at the borders and lumina of a proportion of lacunae and canaliculi surrounding cementocytes in cellular cementum, as well as on inserted periodontal ligament (PDL) fibres. Biglycan was also present along incremental lines in cellular cementum, whereas staining for fibromodulin was negative. In acellular cementum, no immunoreactivity was evident with any of the antibodies used except on inserted PDL fibres. These results indicate that versican, decorin, biglycan and lumican are components of the ECM of cellular, but not of acellular cementum. Neither age nor periodontal diseases appear to qualitatively influence the PG population of cementum. The distribution of PG epitopes around a proportion of cementocytes suggests the existence of different cementocyte subpopulations, or a differential response of these cells to yet undefined stimuli.

Adsorption of glycosaminoglycans onto hydroxyapatite using chromatography.

Proteoglycans are known to play an important role in the mineralization process, acting either as promoters or inhibitors. In this study the binding affinity of a variety of constituent glycosaminoglycan to hydroxyapatite was studied. Glycosaminoglycans (10-1000 microg ml(-1) in 0.02 M sodium acetate (pH 6.8) were constantly circulated through a hydroxyapatite column for 1 h. The total amount of glycosaminoglycan bound was determined by dimethylmethylene blue assay. The relative affinities of the different glycosaminoglycans remaining bound to hydroxyapatite was investigated by examining their release in a 0-1 M sodium phosphate gradient. Differences were noted between the desorption profiles of dermatan sulfate with two elution peaks and chondroitin 4-sulfate and chondroitin 6-sulfate each with a single peak. Dermatan sulfate and chondroitin 6-sulfate had a higher affinity for hydroxyapatite than chondroitin 4-sulfate possibly due to the presence of differing di-sulfated disaccharide ratios in the glycosaminoglycan chains. These findings suggest the presence of a variety of binding forms of each glycosaminoglycan or the differing orientation of these forms to yield different complexes with hydroxyapatite. The Ca2+ co-ordinates of the glycosaminoglycans are known to vary and may in part explain these findings.