SpectraCam® : A new polarized hyperspectral imaging system for repeatable and reproducible in vivo skin quantification of melanin, total hemoglobin, and oxygen saturation.

BACKGROUND: An accurate way to determine skin pigmentation is to acquire the spectral reflectance of a skin sample and to quantify chromophores by reverse calculation from physical models of light propagation. Therefore, we tested a new hyperspectral imaging device and software suite, the SpectraCam® system, and evaluated its accuracy to quantify skin chromophores. METHODS: Validation of the SpectraCam® system was performed by, firstly, comparing the known and the acquired reflectance spectra of color phantoms. Repeatability and reproducibility were then evaluated by two operators who performed acquisitions at different time points and compared the acquired reflectance spectra. The specificity of the system was tested by quantitative analysis of single chromophore variation models: lentigo and pressure relief. Finally, we tested the ability of the SpectraCam® system to detect variations in chromophore in the eye region due to the daily application of a new anti-dark circle cosmetic product. RESULTS: The SpectraCam® system faithfully acquires the reflectance spectra of color phantoms (r2 >0.90). The skin reflectance spectra acquired by different operators at different times are highly repeatable (r2 >0.94) and reproducible (r2 >0.99). The SpectraCam® system can also produce qualitative maps that reveal local variations in skin chromophore or underlying structures such as blood vessels. The system is precise enough to detect melanin variation in lentigo or total hemoglobin and oxygen saturation variations upon pressure relief. It is also sensitive enough to detect a decrease in melanin in the eye region due to the application of an anti-dark circle cosmetic product. CONCLUSION: The SpectraCam® system proves to be rapid and produces high-resolution data encompassing a large field of view. It is a robust hyperspectral imaging system that quantifies melanin, total hemoglobin, and oxygen saturation and is well adapted to cosmetic research.

Identification of new morphological differences between Chinese and Caucasian faces and influence of BMI on these characteristics.

BACKGROUND: Concepts of beauty are more and more globalised leading to the homogenisation of the physical appearance. It is therefore important to identify morphological characteristics of ethnic groups. We compare faces from Chinese and Caucasian women, identify morphological differences that were not documented yet and study the influence of BMI on these differences. METHODS: The study was carried on groups of 60 women: a Chinese and a Caucasian group. Both included two equal sub-groups: normal BMI and higher BMI. Face widths were measured from individual pictures and from reconstructed average faces obtained using a new reconstruction algorithm. Cheek/chin and neck/chin angles were determined from individual pictures. Topography of the cheekbone and temple face was determined by fringe projection technique. Ultrasound analysis allows measurements of hypodermis thickness. RESULTS: Our innovative average face reconstruction algorithm produced images of a yet unequalled quality with width characteristics similar to those of individual pictures. Analysis shows that faces of Chinese women are larger and rounder. They present other differences that were so far unidentified. Finally, overweight impacts differently Chinese and Caucasian women faces and has greater influence on Chinese women faces.

Fractional anisotropy distributions in 2- to 6-year-old children with autism.

BACKGROUND: Increasing evidence suggests that autism is a disorder of distributed neural networks that may exhibit abnormal developmental trajectories. Characterisation of white matter early in the developmental course of the disorder is critical to understanding these aberrant trajectories. METHODS: A cross-sectional study of 2- to 6-year-old children with autism was conducted using diffusion tensor imaging combined with a novel statistical approach employing fractional anisotropy distributions. Fifty-eight children aged 18-79 months were imaged: 33 were diagnosed with autism, 8 with general developmental delay, and 17 were typically developing. Fractional anisotropy values within global white matter, cortical lobes and the cerebellum were measured and transformed to random F distributions for each subject. Each distribution of values for a region was summarised by estimating δ, the estimated mean and standard deviation of the approximating F for each distribution. RESULTS: The estimated δ parameter, , was significantly decreased in individuals with autism compared to the combined control group. This was true in all cortical lobes, as well as in the cerebellum, but differences were most robust in the temporal lobe. Predicted developmental trajectories of across the age range in the sample showed patterns that partially distinguished the groups. Exploratory analyses suggested that the variability, rather than the central tendency, component of was the driving force behind these results. CONCLUSIONS: While preliminary, our results suggest white matter in young children with autism may be abnormally homogeneous, which may reflect poorly organised or differentiated pathways, particularly in the temporal lobe, which is important for social and emotional cognition.

Mechanisms of action in the liver of crilvastatin, a new hydroxymethylglutaryl-coenzyme A reductase inhibitor.

Crilvastatin is a drug from the pyrrolidone family that had been shown to induce non-competitive inhibition of rat hydroxymethylglutaryl-coenzyme A reductase activity in vitro. The aim of this study was to evaluate the activity of crilvastatin on the hepatic metabolism of cholesterol in rats. Crilvastatin increased low density lipoprotein (LDL)-cholesterol uptake by the liver more than high density lipoprotein (HDL) uptake, thus increasing by up 30% the clearance of excess plasma cholesterol. In normolipidemic rats, crilvastatin significantly enhanced acyl coenzyme A:cholesterol acyl transferase and cholesterol 7 alpha-hydroxylase activity. In rats with a previous high cholesterolemia, crilvastatin also enhanced cholesterol 7 alpha-hydroxylase activity and did not increase liver acyl coenzyme A:cholesterol acyl transferase activity. These findings suggest that a drug such as crilvastatin could have a hypocholesterolemic effect by a mechanism other than the sole inhibition of cholesterol synthesis, possibly by stimulating cholesterol and bile salt secretion via the biliary tract in previously hypercholesterolemic rats.

[Outcome of 404 premature infants born before 32 weeks of gestation in 1978-1980]. / Devenir de 404 prématurés nés avant 32 semaines de gestation en 1978-1980.

The outcome of 404 prematures born before 32 weeks of gestation and admitted on the first day of life to the Institut de Puériculture (IP) in 1978-1980 was studied with respect to post-menstrual age and birth weight: 83 (20,5%) died during the hospitalization. Of the 321 still alive after the neonatal hospitalization, 71% were followed until at least 2 years of age; 3,1% died unexpectedly at home. There was a 8% handicap rate (9 with cerebral palsy and 9 with psychomotor deficiency) in the survivors. The problems of the children without handicap consisted mostly of strabismus and psychosocial disturbances. Thus, on admission to the IP on the first day of life during 1978-1980, according to gestational age (a) less than 28 weeks, (b) between 28 and 29 weeks 6 days (c) between 30 and 31 weeks 6 days, a premature presented the following risks: death during hospitalization: (a) 47%, (b) 20% and (c) 15%; death at home (b) 5%, (c) 1%; handicap (a) 3%, (b) 10%, (c) 5%; normal survival (a) 47%, (b) 63%, (c) 75%. This study shows the value of gestational age in estimating the outcome of prematures and the utility of analysing the results according to the 2 variables of gestational age and birth weight.