Classification of burn injuries using near-infrared spectroscopy

Early surgical management of those burn injuries that will not heal spontaneously is critical. The decision to excise and graft is based on a visual assessment that is often inaccurate but yet continues to be the primary means of grading the injury. Superficial and intermediate partial-thickness injuries generally heal with appropriate wound care while deep partial- and full-thickness injuries generally require surgery. This study explores the possibility of using near-infrared spectroscopy to provide an objective and accurate means of distinguishing shallow injuries from deeper burns that require surgery. Twenty burn injuries are studied in five animals, with burns covering <1% of the total body surface area. Carefully controlled superficial, intermediate, and deep partial-thickness injuries as well as full-thickness injuries could be studied with this model. Near-infrared reflectance spectroscopy was used to evaluate these injuries 1 to 3 hours after the insult. A probabilistic model employing partial least-squares logistic regression was used to determine the degree of injury, shallow (superficial or intermediate partial) from deep (deep partial and full thickness), based on the reflectance spectrum of the wound. A leave-animal-out cross-validation strategy was used to test the predictive ability of a 2-latent variable, partial least-squares logistic regression model to distinguish deep burn injuries from shallow injuries. The model displayed reasonable ranking quality as summarized by the area under the receiver operator characteristics curve, AUC = 0.879. Fixing the threshold for the class boundaries at 0.5 probability, the model sensitivity (true positive fraction) to separate deep from shallow burns was 0.90, while model specificity (true negative fraction) was 0.83. Using an acute porcine model of thermal burn injuries, the potential of near-infrared spectroscopy to distinguish between shallow healing burns and deeper burn injuries was demonstrated. While these results should be considered as preliminary and require clinical validation, a probabilistic model capable of differentiating these classes of burns would be a significant aid to the burn specialist.     

Age-related decrease in high-density lipoproteins antioxidant activity is due to an alteration in the PON1's free sulfhydryl groups

The aim of this study was to evaluate the antioxidant activity of HDL with aging and to investigate the implication of PON1 in this process. The study involved 54 healthy subjects distributed in two age groups, young (20-25 years) and elderly (65-85 years). Lipid peroxidation was induced by *OH and O2*- oxygen free radicals produced by gamma-radiolysis of water. LDL oxidation was followed by the measurement of conjugated diene (CD), lipid peroxide (LP) and malondialdehyde (MDA) formation. PON1 was purified separately from young (Y-PON1) and elderly subjects (E-PON1). PON1 activity and structure was followed by measurement of PON1 paraoxonase (p.ase) activity, titration of the SH groups, and electrophoretic mobility by SDS-PAGE. Our results show a significant decrease in the HDL antioxidant activity: percentage of protection against CD formation=27.70% (p<0.01) for E-HDL versus 73.08% (p<0.001) for Y-HDL. Moreover, E-PON1 showed a lower antioxidant activity when compared to Y-PON1 47.08% versus 78.14%, respectively (p<0.0001). Exposition of PON1 to *OH and O2*- oxygen free radicals induced a significant decrease in PON1 p.ase activity as well as a reduction in the number of PON1's free sulfhydryl groups. Moreover, our results show a close association between PON1's free sulfhydryl groups and its capacity to protect LDL against lipid peroxidation. There was a significant decrease in the number of free sulfhydryls between Y-PON1 and E-PON1 with respect to cysteine-284 amino acid residues (p<0.0092).     

Rubella Virus-associated Anterior Uveitis in a Vaccinated Patient: A Case Report

Rubella virus is involved in the pathogenesis of Fuchs heterochromic uveitis and almost all cases in Europe show an active antibody production in the aqueous humor against rubella virus. Herein we report a case of a fully vaccinated patient with common variable immunodeficiency who developed unilateral Fuchs heterochromic uveitis secondary to rubella virus which was proven by intraocular fluid examination. Awareness of rubella associated anterior uveitis should remain also in vaccinated patients, especially those without a fully competent immune system.     

Transcultural,transdiagnostic, and concurrent validity of a revised metacognitions about symptoms control scale

Anxiety and depression add to the burden of chronic fatigue syndrome (CFS), fibromyalgia (FM), and type 1 diabetes mellitus (T1DM). Metacognitions play a role in this distress. The metacognitions about symptoms control scale (MaSCS) measure metacognitive beliefs regarding symptoms but have weaknesses. The current study created a revised MaSCS (MaSCS‐R) in English, German, and Arabic versions using CFS, FM, and T1DM samples and examined the transcultural, transdiagnostic, and concurrent validity of metacognitions about symptom control. This study used data from 563 participants clinically diagnosed with CFS (n = 124; English), FM (n = 348; German), or T1DM (n = 91; Lebanese). CFS and FM data had been used in earlier published studies but were subjected to new analyses. CFS data were used to create the English version of the MaSCS‐R and FM and T1DM data for German and Arabic versions. Metacognitions about worry, anxiety, depression, and symptom severity were measured. The three MaSCS‐R versions, consisting of two factors (each with four items), had adequate psychometric properties, possessing configural and metric invariance. Metacognitive factors were associated with distress and symptom severity in all three samples. Metacognitions about symptom control have transcultural, transdiagnostic, and concurrent validity.     

Community periodontal index of treatment needs and prevalence of periodontal conditions

BACKGROUND/AIMS: In 1977, the World Health Organization (WHO) proposed a new index, the community periodontal index of treatment needs (CPITN) to evaluate the periodontal treatment needs of populations. The aim of this study is to compare different approaches of recording and presenting the CPITN. METHODS: A sample of 2110 subjects aged 35-44 years were examined between September 1994 and July 1995, throughout the province of Quebec, Canada. For each tooth (3rd molars excluded), the presence of bleeding and calculus, the level of epithelial attachment, and the depth of periodontal pockets were measured. Periodontal pocket depths were measured from the edge of the free gingiva, at 2 sites (mesiovestibular and vestibular), as well as all around the tooth. RESULTS: Only 8.5% of adults had at least one tooth with a 6 mm or deeper periodontal pocket when probing on 2 sites, whereas if probing is done all around the tooth, this percentage is 2.5x higher (21.4%). The partial recording of pocket depths (10 index teeth recommended by WHO, or 2 quadrants chosen at random) resulted in an underestimation of the prevalence of subjects with at least one tooth with a periodontal pocket (CPITN score 3 and 4). Among subjects with at least one tooth with a 6 mm or deeper periodontal pocket, 12% were not detected with the 10 index teeth recording, and 25% go undetected with the measure on 2 quadrants. Finally, using the % of subjects with periodontal pockets overestimates the prevalence of deep pockets compared with using sextants. Indeed, close to 30.0% of sextants have no treatment needs, whereas only 5.2% of subjects are in this category. Similarly, 7.7% of sextants have at least one tooth with a 6 mm or deeper periodontal pocket, yet there are 3x more subjects in this category (21.4%).     

Comparison of the pupil card and pupillometer in measuring pupil size

PURPOSE: To determine the difference in pupil size measured with the Colvard pupillometer in mesopic and scotopic luminance and with the Rosenbaum pupil card in mesopic luminance between 2 examiners. SETTING: Michel Pop Clinics, Montreal, Quebec, Canada. METHODS: Two examiners used the Colvard pupillometer and the Rosenbaum card to measure pupil size in 58 eyes. The Colvard pupillometer was used in mesopic and scotopic light conditions. The Rosenbaum card was used in mesopic luminance only. Pupil size was evaluated with a 1.0 mm interval scale at the nearest half millimeter. RESULTS: For the 3 sets of data, the limits of agreement and coefficient of interrater repeatability were calculated and a 2 x 2 factorial analysis of variance was performed. Because of interexaminer bias, measurements done in mesopic luminance with the Rosenbaum card were not statistically different from those with the Colvard pupillometer in scotopic luminance, although interrater repeatability of the Colvard pupillometer (0.8 mm) was superior to that of the Rosenbaum card (1.3 mm). CONCLUSIONS: Examiner bias was the greatest statistical bias in all sets of measures. Surgeons may want to opt for a "safe" limit of pupil size (ie, 0.5 to 0.8 mm greater than the measured size) when calculating optical zones in refractive surgery. Future devices for pupil measurement should be based on automatic adjustment sizing.