The use of optical coherence tomography for skin evaluation in healthy rats.

BACKGROUND: Noninvasive diagnostic techniques allow for morphological and morphometric in vivo evaluation of the skin. Optical coherence tomography (OCT) is a method that allows visualization of dermal structures up to several 100 µm with a resolution of 3-7.5 µm. OBJECTIVES: The aim of the study was the morphological and morphometric assessment of rats' skin using SD-OCT. ANIMALS: Fifteen male Wistar rats, aged 3 and 8 months, weighing 350-450 g. MATERIALS AND METHODS: The skin of the plantar metatarsal area of the right pelvic limb was assessed. The measurements were performed using Spectral Domain Optical Coherence Tomography (SD-OCT) scans and histological images. RESULTS: Spectral Domain Optical Coherence Tomography could determine the boundary between the epidermis and the dermis. Apart from the stratum corneum (SC), it did not allow for the differentiation of the individual epidermal layers. In the SD-OCT and in the histological examination, the mean thicknesses of the layers (µm ± SD) were (respectively): SC 33.053 ± µm(SD 5.85, 29.675 ± 5.54; epidermis 88.2 ± 7.97, 65.126 ± 13.23; dermis 259.86 ± 18.29, 166.05 ± 31.88 µm. There was a correlation between the total epidermal SD-OCT and histological measurements (r = 0.43, p = 0.05). Bland-Altman plots revealed a bias of -19.18 (95% confidence interval) -39.21 to 0.84 µm) in the case of live epidermis (stratum granulosum, stratum spinous, stratum basale). CONCLUSIONS AND CLINICAL RELEVANCE: Spectral Domain Optical Coherence Tomography can be used to evaluate rat epidermis and dermis. The method enables the differentiation of the SC, as well as the epidermis and the dermis. SD-OCT and histological thickness dimensions of the epidermis and skin differ.

Contexte - Les techniques de diagnostic non invasives permettent une évaluation morphologique et morphométrique in vivo de la peau. La tomographie par cohérence optique (OCT) est une méthode qui permet de visualiser les structures dermiques jusqu'à plusieurs centaines de micromètres avec une résolution de 3 à 7,5 µm. Objectifs - Le but de l'étude était l'évaluation morphologique et morphométrique de la peau des rats par SD-OCT. Animaux - Quinze rats Wistar mâles, âgés de 3 et 8 mois, pesant 350-450 g. Matériels et méthodes - La peau de la zone métatarsienne plantaire du membre pelvien droit a été évaluée. Les mesures ont été réalisées à l'aide de scaners SD-OCT (Spectral Domain Optical Coherence Tomography) et d'images histologiques Résultats - Le SD-OCT a pu déterminer la frontière entre l'épiderme et le derme. En dehors de la couche cornée (SC), il n'a pas permis la différenciation des couches épidermiques individuelles. Au SD-OCT et à l'examen histologique, les épaisseurs moyennes des couches (µm ± SD) étaient (respectivement) : SC 33,053 ± µm (SD 5,85, 29,675 ± 5,54 ; épiderme 88,2 ± 7,97, 65,126 ± 13,23 ; derme 259,86 ± 18,29, 166,05 ± 31,88 µm). Il y avait une corrélation entre le SD-OCT épidermique total et les mesures histologiques (r = 0,43, P = 0,05) Les tracés de Bland-Altman ont révélé un biais de -19,18 (intervalle de confiance à 95 %) -39,21 à 0,84 µm) dans le cas d'épiderme vivant (stratum granulosum, stratum spinous, stratum basale). Conclusions et pertinence clinique - Le SD-OCT peut être utilisé pour évaluer l'épiderme et le derme de rat. La méthode permet de différencier le SC, ainsi que l'épiderme et le derme. Le SD-OCT et les dimensions d'épaisseur histologiques de l'épiderme et de la peau diffèrent.

Introducción - las técnicas de diagnóstico no invasivas permiten la evaluación morfológica y morfométrica in vivo de la piel. La tomografía de coherencia óptica (OCT) es un método que permite la visualización de estructuras dérmicas de hasta varios cientos de micrómetros con una resolución de 3 a 7,5 µm. Objetivos - El objetivo del estudio fue la evaluación morfológica y morfométrica de la piel de ratas mediante SD-OCT. Animales - Quince ratas Wistar macho, de 3 y 8 meses de edad, con un peso de 350 a 450 g. Materiales y métodos - Se evaluó la piel de la zona metatarsiana plantar del miembro pélvico derecho. Las mediciones se realizaron utilizando escaneos SD-OCT (Tomografía de Coherencia Óptica de Dominio Espectral) e imágenes histológicas. Resultados - SD-OCT pudo determinar el límite entre la epidermis y la dermis. Aparte del estrato córneo (SC), no permitía la diferenciación de las capas epidérmicas individuales. En la SD-OCT y en el examen histológico, los espesores medios de las capas (µm ± SD) fueron (respectivamente): SC 33.053 ± µm (SD 5.85, 29.675 ± 5.54; epidermis 88.2 ± 7.97, 65.126 ± 13.23; dermis 259.86 ± 18,29, 166,05 ± 31,88 µm. Hubo una correlación entre el SD-OCT epidérmico total y las mediciones histológicas (r = 0,43, P = 0,05). Las gráficas de Bland-Altman revelaron un sesgo de -19,18 (intervalo de confianza del 95 %) -39,21 a 0,84 µm) en el caso de epidermis viva (estrato granuloso, estrato espinoso, estrato basal). Conclusiones y relevancia clínica- SD-OCT se puede utilizar para evaluar la epidermis y la dermis de rata. El método permite diferenciar el SC, así como la epidermis y la dermis. Las dimensiones de grosor de la epidermis y la piel difieren entre SD-OCT y la histología.

Contexto - Técnicas diagnósticas não invasivas permitem a avaliação morfológica e morfométrica in vivo da pele. A tomografia de coerência óptica (OCT) é um método que possibilita a visualização de estruturas dérmicas de até centenas de micrômetros com uma resolução de 3-7,5 µm. Objetivos - O objetivo do estudo foi a avaliação morfométrica e morfológica da pele de ratos utilizando SD-OCT. Animais - Quinze ratos Wistar machos, de três a oito meses de idade, pesando de 350 a 450 g. Materiais e métodos - A pele da região metatársica plantar do membro pélvico direito foi avaliada. As mensurações foram realizadas utilizando o SD-OCT (Spectral Domain Optical Coherence Tomography) e imagens histológicas. Resultados - A SD-OCT foi capaz de determinar o limite entre derme e epiderme. A exceção do estrato córneo (SC), não foi possível a diferenciação das camadas da epiderme individualmente. Na SD-OCT e na avaliação histológica, as espessuras médias das camadas fora, (µm ± DP), respectivamente: SC 33,053 ± 5,85; 29,675 ± 5,54; epiderme 88,2 ± 7,97; 65,126 ± 13,23; derme 259,86 ± 18,29; 166,05 ± 31,88 µm. Houve correlação entre SD-OCT e avaliação histológica nas mensurações da epiderme total (r = 0,43, P = 0,05). Os gráficos de Bland-Altman revelaram um viés de -19,8% (95% de intervalo de confiança) - 39,21 a 0,84 µm) no caso da epiderme viva (estrato espinhoso, estrato granuloso e estrato basal). Conclusões e relevância clínica - SD-OCT pode ser utilizada para avaliar a derme e a epiderme de ratos. Este método permite a diferenciação do SC, bem como da derme e epiderme. Pode haver discrepância na espessura da epiderme e da pele na SD-OCT e análise histológica.

The Inhibitory Effect of Selected D2 Dopaminergic Receptor Agonists on VEGF-Dependent Neovascularization in Zebrafish Larvae: Potential New Therapy in Ophthalmic Diseases.

Pathological angiogenesis is correlated with many ophthalmic diseases. The most common are exudative age-related macular degeneration and proliferative diabetic retinopathy. The current treatment for these diseases is based on regularly administered anti-VEGF antibodies injections. In the study, we investigated selected D2 dopaminergic receptor agonists, namely bromocriptine, cabergoline and pergolide, on hypoxia-induced neovascularization. We used the zebrafish laboratory model, specifically three-day post fertilization (dpf) Tg(fli-1: EGFP) zebrafish larvae. To induce abnormal angiogenesis of hyaloid-retinal vessels (HRVs) and intersegmental vessels (ISVs), the larvae were treated with cobalt chloride (II) (CoCl2) (a hypoxia-inducing agent) from 24 h post fertilization. The inhibitory role of D2 dopaminergic receptor agonists was investigated using confocal microscopy and qPCR. Additionally, the results were compared to those obtained in the group treated with CoCl2 followed by bevacizumab, the well-known antiangiogenic agent. Confocal microscopy analyses revealed severe deformation of vessels in the CoCl2 treated group, while co-incubation with bromocriptine, cabergoline, pergolide and bevacizumab, respectively, significantly inhibited abnormalities of angiogenesis. The qPCR analyses supported the protective role of the chosen dopaminergic agonists by demonstrating their influence on CoCl2-derived upregulation of vegfaa expression. The present results suggest that the D2 receptor agonists can be considered as a new direction in research for antiangiogenic therapy.

The impact of age, sex, blepharitis, rosacea and rheumatoid arthritis on Demodex mite infection.

INTRODUCTION: Two human-specific Demodex species have been described: Demodex folliculorum and Demodex brevis. A medical condition caused by the presence of Demodex is called demodicosis. MATERIAL AND METHODS: The study material comprised eyelashes collected from 1499 patients. RESULTS: Demodex sp. infection was revealed in 47% of patients (487 women and 216 men). We determined the following rates of infection by age groups: 1-25 (8% of infected subjects), 26-40 (36%), 41-55 (50%), 56-70 (67%), over 70 (77%). The sex of the subjects was not identified as a factor conducive to infection (p = 0.108), while their age was positively correlated with the risk of infection (p < 0.005). The 1499 study subjects included patients with blepharitis, rosacea, and rheumatoid arthritis. The study investigated the extent to which the above-mentioned conditions affect the risk of Demodex infection. Applying the method of logistic regression, the infection probability was estimated, depending on the age, sex, and comorbidities such as blepharitis, rosacea, and rheumatoid arthritis. Patients suffering from blepharitis were found to have a nearly 2.5-fold higher risk of Demodex infection than those without blepharitis, and the risk for rosacea patients was determined as three-fold higher than that of the general population. CONCLUSIONS: Blepharitis and rosacea are risk factors for Demodex infection.

Ocular symptoms reported by patients infested with Demodex mites.

The purpose of this study was to determine subjective ocular symptoms occurring in patients infested with Demodex. The number of Demodex mites in the obtained material that correlated with the appearance of ocular symptoms was estimated. The study material were eyelashes collected from 1499 patients. The material were observed under a light microscope. T-test, the logistic regression method, and Pearson correlation coefficient were used for the analysis. Demodex mites were detected in 47% patients. The mean ages of infected women and men were 64 and 59 years, respectively. 64% infected patients complained of one or more ophthalmological symptoms. The most commonly reported symptoms included itching (28%), redness of eyelids (21%), and watery eyes (15%). Positive correlation was found between itching, redness, pain, purulence or eyelash loss and the presence of Demodex. The mentioned symptoms increase the probability of Demodex infestation in a statistically significant manner (p<0.005). A correlation between the age and gender and the number of Demodex was revealed by the study. The threshold average number of seven Demodex mites per eight collected eyelashes with which the risk of the occurrence of an ocular symptom increases significantly was defined. In patients with a low number of Demodex mites, symptoms may be absent. The risk of the occurrence of ocular symptom in patients with demodicosis increases with the increase in the average number of Demodex mites.