Vascularity and Fractal Dimension of the Dermo-Epidermal Interface in Guttate and Plaque-Type Psoriasis

Immunohistochemical patterns in the interfollicular Caucasian scalps: influences of age, gender, and alopecia

Skin ageing and gender influences on the scalp have been seldom studied. We revisited the changes in the interfollicular scalp. The study was performed on a population of 650 volunteers (300 women and 350 men) for over 7 years. Three age groups were selected in both genders, namely, subjects aged 20–35, 50–60, and 60–70 years. The hair status was further considered according to nonalopecic and alopecic patterns and severity (discrete, moderate, and severe). Biopsies from the parietal area were processed for immunohistochemistry. Stromal cells were distinguished according to the presence of vimentin, Factor XIIIa, CD117, and versican. Blood and lymphatic vessels were highlighted by Ulex europaeus agglutinin-1 and human podoplanin immunoreactivities, respectively. Actinic elastosis was identified by the lysozyme coating of elastic fibres. The epidermis was explored using the CD44 variant 3 and Ki67 immunolabellings. Biplot analyses were performed. Immunohistochemistry revealed a prominent gender effect in young adults. Both Factor XIIIa+ dermal dendrocytes and the microvasculature size decreased with scalp ageing. Alopecia changes mimicked stress-induced premature senescence.

Character of skin on photo-thermal response and its regeneration process using second-harmonic generation microscopy

Quantitative characterization of skin collagen on photo-thermal response and its regeneration process is an important but difficult task. In this study, morphology and spectrum characteristics of collagen during photo-thermal response and its light-induced remodeling process were obtained by second-harmonic generation microscope in vivo. The texture feature of collagen orientation index and fractal dimension was extracted by image processing. The aim of this study is to detect the information hidden in skin texture during the process of photo-thermal response and its regeneration. The quantitative relations between injured collagen and texture feature were established for further analysis of the injured characteristics. Our results show that it is feasible to determine the main impacts of phototherapy on the skin. It is important to understand the process of collagen remodeling after photo-thermal injuries from texture feature.

Ustekinumab biotherapy and real-time psoriasis capacitance mapping: a pilot study

In recent years, the treatment of moderate to severe psoriasis has benefited from the development of targeted biologicals. Assessing this new class of drugs calls for precise modalities of severity/improvement ratings of the disease. Bioengineering-driven dermometrology aims at improving objective and quantitative assessments of disease severity and treatment efficacy. Skin capacitance mapping/imaging is one of those emerging methods. Among its clinical applications, psoriasis capacitance mapping (PCM) was introduced in order to assess both skin scaliness and water trapping inside the stratum corneum (inflammatory serum deposits) on lesional skin. PCM was used for assessing the therapeutic effects of ustekinumab on target lesions of 5 psoriatic patients. The reduction in the inflammatory dampness of the stratum corneum was conveniently seen after a 1-month ustekinumab treatment. The present pilot study suggests that PCM could be used as a fast and convenient method for assessing the anti-inflammatory efficacy of ustekinumab and other biotherapies.

Micro computed tomography for vascular exploration

Vascular exploration of small animals requires imaging hardware with a very high spatial resolution, capable of differentiating large as well as small vessels, in both in vivo and ex vivo studies. Micro Computed Tomography (micro-CT) has emerged in recent years as the preferred modality for this purpose, providing high resolution 3D volumetric data suitable for analysis, quantification, validation, and visualization of results. The usefulness of micro-CT, however, can be adversely affected by a range of factors including physical animal preparation, numerical quantification, visualization of results, and quantification software with limited possibilities. Exacerbating these inherent difficulties is the lack of a unified standard for micro-CT imaging. Most micro-CT today is aimed at particular applications and the software tools needed for quantification, developed mainly by imaging hardware manufacturers, lack the level of detail needed to address more specific aims. This review highlights the capabilities of micro-CT for vascular exploration, describes the current state of imaging protocols, and offers guidelines and suggestions aimed at making micro-CT more accurate, replicable, and robust.

[Spectral analysis of the microvasculature of primary cutaneous melanoma]

Cutaneous malignant melanoma represents one of the most dramatic skin cancers because its incidence is steadily growing in White populations. Of note, its metastatic risk and mortality dramatically increase when the primary neoplasm reaches about one millimeter thick. It is believed that angiogenesis and lymphangiogenesis associated with cutaneous melanoma potentially influence the neoplastic progression of the primary tumor and its metastases. In some instances, both the intratumoral and peritumoral microvasculature are correlated to booming of the tumoral growth fraction. In addition, the vascular network serves as a migration path for the intravascular and perivascular neoplastic spread. Hence, the quantification of the microvasculature might help establishing a prognostic factor of evolution. Among the available methods, spectral analysis of immunohistochemical sections highlighting vessels helps defining the microvasculature distribution. The benefit of using spectral analysis is discussed and the modalities of application of this analytical method are scrutinized.

Immunohistochemical clues at aging of the skin microvascular unit

BACKGROUND

Skin aging is a multifaceted process influenced by various factors affecting at variable degree at different body sites. This study focused on the aging process affecting dermal dendrocytes and the microvasculature. We also explored the effect of substance P released by capsaicin because this neuropeptide is known to affect the microvasculature environment.

METHODS

The first part of the present study was undertaken in two groups of 35 men who were younger than 30 years and older than 65 years, respectively. A skin biopsy was taken from the intact skin of a thigh during orthopedic surgical intervention after road accident. The second part of the study was performed on 30 men aged 65-68 years. They applied once daily a 0.05% capsaicin gel and the vehicle in a randomized design on the volar forearms. A skin biopsy was taken at inclusion and after a 5-month treatment phase. Immunohistochemistry was performed using a panel of antibodies. Dermal cells were distinguished according to the presence of factor XIIIa, CD34 or thrombomodulin. Blood and lymphatic vessels were studied by Ulex europaeus agglutinin-1, human podoplanin, human vascular endothelial growth factor-C (H-VEGF-C) and alpha-actin immunoreactivities.

RESULTS

In the study phase 1, a significant decrease in thrombomodulin-positive cells and vascularity were evidenced in the aged group. In the study phase 2, capsaicin appeared to boost the factor XIIIa-positive dendrocytes, the thrombomodulin-positive cells and the blood vessel network as well.

CONCLUSIONS

Specific subsets of the dermal dendrocyte populations and the blood microvasculature appear affected by aging. Capsaicin may limit these aging effects.

Skin capacitance mapping of psoriasis

BACKGROUND

The pathobiological dynamics of psoriatic lesions are complex and difficult to perceive by clinical inspection alone. Non-invasive bioengineering methods may prove to be useful in this field.

OBJECTIVE

To identify some subtle capacitance variations in the stratum corneum of chronic psoriasis lesions.

METHOD

The newly developed method of skin capacitance imaging was used to provide non-optical images of the hydration of the superficial layers of the stratum corneum.

RESULTS

Compared to the uninvolved skin, psoriatic lesions usually showed an overall lowered capacitance, admixed with foci of moderately higher capacitance. Still other sharply circumscribed blotches with higher capacitance were present. The latter aspect corresponded to inflammatory areas. Sweating appeared markedly impaired inside the lesions. The fingerprint of some patients was altered, thus potentially interfering with the current biometric security procedures using the same method.

CONCLUSION

Skin capacitance imaging is a non-invasive, non-optical method that distinguishes three contrasting levels of stratum corneum hydration in psoriatic lesions. The lowest capacitance level probably corresponded to xerotic orthokeratosis. The medium capacitance level presumably identified foci of parakeratosis and clumps of neutrophils. The highest capacitance level suggested exsudation at the site of prominent vessel dilation and dermal inflammation. Impaired sweating in the psoriatic lesions may potentially interfere with body thermoregulation.

Blood vessel changes during pregnancy: a review

The profound endocrine upheaval of pregnancy is frequently associated with changes in the function and structure of the blood and lymph microvasculature of the skin and mucosae. Palmar erythema is frequent but rarely severe and is associated with burning sensations. Spider telangiectasias develop in the majority of pregnant White women but are less often identified in women with darker skin. Hemangiomas and glomus tumors occur in one-third of women. A firm edema may develop on the face and extremities in the final months of pregnancy. Venous hypertension and varicosities of the lower limbs are common. Gingivitis, gum hypertrophy, and pyogenic granuloma are common in the oral cavity. The vaginal mucosa is also affected, showing a violaceous aspect, at times accompanied by varicosities of the vulva. Many gestational vascular changes regress spontaneously in the postpartum phase. Some vascular tumors may need to be treated with a vascular laser or intense pulsed light.