[Liminal perception threshold of cutaneous distension]

BACKGROUND

Cutaneous sensorial perception is complex and proves to be difficult to quantify. Skin sensitivity to mechanical distension is largely unexplored. We have developed an original method aimed at quantifiying these physiological parameters.

VOLUNTEERS AND METHODS

The study was performed on 24 adult volunteers aged 20 to 50 years. A Cutometer SEM 474 equipped with 2 and 4 mm diameter probes was used to exert a progressive or a steep suction on the cheeks. The intensities of both the suction and the skin deformation observed at the earliest moment the traction was perceived by the volunteers were recorded.

RESULTS

The liminar sensorial detection under progressive suction force was 1.5 times lower when using the 4 mm probe than the 2 mm probe. Suction necessary for liminar sensation was 7 times lower under steep suction than in response to the progressive mode. The skin deformation corresponding to the liminar sensorial perception was almost constant (C=0.5 p. 100) for each subject. By contrast, a large inter individual heterogeneity unrelated to age was present.

COMMENTS

Sensitivity of facial skin to stretching can be explored using a precise suction method. Perception is more related to the rate of traction than to the surface area submitted to suction. Cutaneous deformation, nearly constant for each individual, appears to be the main parameter. Steep and progressive suctions appear to stimulate distinct types of mechanoreceptors. The presently described method can be applied in cosmetology and in functional investigation of various diseases such as diabetes, acromegaly and atopic dermatitis among others.

[Uterine artery embolization for symptomatic uterine fibromas. Informed consent of the patient]

It would seem necessary that an information sheet and written consent should be exchanged and signed by the physician and the patient, especially when interventional radiology procedures are involved. A comprehensive interview with full explanation is also mandatory if the patient is to be adequately informed. The existence of a specific document provides two benefits: For the patient: an understanding of the procedure and of the associated risks and benefits tends to reduce the natural anxiety which stems from ignorance and better prepares her to make an informed decision on whether to agree (i.e. give consent) to the procedure or decline it. For the physician: the document represents a formal way of demonstrating that he or she has fulfilled his or her duties in the matter of patient information and consent. A written form would seem to be the best solution to meet these requirements. A document of this type is proposed in this case in the form of a series of questions and answers about embolization of the uterine arteries as a modality for the treatment of symptomatic uterine fibroids.

[How I investigate...atypical cutaneous mycobacteriosis]

Atypical mycobacterioses affecting the skin are diverse and their treatments are different as well. These diseases show an increasing prevalence. The contamination occurs from the environment while interhuman transmission does not occur.

The SACD method and the XLRS squamometry tests revisited

The assessment of many aspects of the structure and biological dynamics of the stratum corneum can be conducted using calibrated stripping with adhesive-coated discs (SACD). Squamometry entails staining SACD samples with a toluidine blue-basic fuschsin ethanol-based solution and reading the colorimetric variable Chroma C* representing the squamometry index. Four main variants of squamometry index have been designed so far. Squamometry X refers to the assessment of xerosis and any scaly condition. Squamometry L explores the intercorneocyte cohesiveness impaired by ultraviolet light. Squamometry R evaluates stratum corneum renewal and squamometry S assesses the effect of surfactants on corneocyte integrity. This latter variant is related to, although not similar to, the ex-vivo corneosurfametry bioassay. All squamometry tests are rapid, reliable, sensitive and cheap.

A randomized, placebo-controlled trial of topical retinol in the treatment of cellulite

BACKGROUND

Cellulite occurs to varying degrees on the thighs and buttocks of many otherwise healthy women. Among the many purported treatments for cellulite, only a handful have been tested in clinical trials.

OBJECTIVE

The aim of this study was to critically explore the reputed effect of topical retinol in the treatment of cellulite.

MATERIALS AND METHODS

The study compared the effect of topical retinol to a placebo formulation in a left-right randomized trial in order to eliminate the massage-effect. The study was conducted in 15 women aged from 26 to 44 years who had requested liposuction to improve mild to moderate cellulite.

RESULTS

After 6-months of treatment, skin elasticity was increased by 10.7% while viscosity was decreased by 15.8% at the retinol-treated site. Such an effect on the tensile properties of skin was more prominent where the mattress phenomenon was the only evidence of cellulite. The lumpy-bumpy appearance of the skin showed either little response or was not responsive to the treatment. Although gross microanatomical differences were not disclosed between the comparative sites at completion of the study, evidence for a shift in the phenotype of connective tissue cells was obtained. The main retinol-related change consisted of a 2- to 5-fold increase in the number of factor XIIIa+ dendrocytes both in the dermis and fibrous strands of the hypodermis.

CONCLUSIONS

We hypothesize that the functional and phenotypic changes seen in this study were linked and represent the result of a direct or indirect modulating effect of retinol on cellulite. Such features ultimately improve the resting tensions inside the skin which should in turn smooth the skin surface.

Ageing and rheological properties of facial skin in women

Ageing affects the mechanical properties of skin. Studies using objective measurements on facial skin have been rare and yielded contradictory information. In the present study, the age-related changes occurring in the mechanical properties of facial skin were reviewed using a computerized suction method. A total of 200 healthy women, aged from 17 to 68 years, were enrolled. Data show a significant increase in skin extensibility and a significant decline in elasticity with ageing. These changes become obvious in women approaching 40 years.

Penetration enhancers assessed by corneoxenometry

Chemical enhancers abating the barrier function of the stratum corneum act in a number of ways. Their relative effects in mixtures are notoriously difficult to determine. Corneoxenometry is a bioassay where xenobiotic interactions with corneocytes are assessed using reflectance colorimetry. It was used to evaluate comparatively the effects of ethanol and laurocapram at various dilutions. In addition, a 10% propylene-glycol-based gel supplemented with N-acetyl-L-cysteine, urea and salicylic acid in various concentrations was tested. The relative index or irritancy (RII) was calculated for each formulation. RII is a surrogate marker of lipid removal and disorganization, and of protein denaturation in the stratum corneum. It is likely a good predictor for barrier function alterations and represents a cheap and rapid alternative to animal testing.

Split-face clinical and bio-instrumental comparison of 0.1% adapalene and 0.05% tretinoin in facial acne

BACKGROUND

Adapalene and tretinoin are topical compounds active for treating acne.

OBJECTIVE

To compare the efficacity and safety of adapalene 0.1% gel and tretinoin 0.05% gel in moderately severe facial acne using clinical and objective biometrological assessments. Such information is currently lacking in the literature.

METHODS

The split-face method was used in 25 acne volunteers for a 6-week treatment. In addition to clinical counts of lesions, the amount of comedones was assessed using computer-assisted morphometry of cyanoacrylate follicular biopsies. The erythema index and squamometry values were used to quantitate skin irritation.

RESULTS

The tretinoin formulation brought better comedolysis and clinical improvement than the adapalene formulation. Erythema was transiently more pronounced on the tretinoin-treated side. Squamometry yielded no significant difference between both products.

CONCLUSION

Tretinoin 0.05% gel exhibits a greater anti-acne efficacy than adapalene 0.1% gel, although with temperate tolerability.

[Pharma-clinics. How I treat ... pruritus by an antihistamine]

Pruritus is a symptom originating from multiple etiologies. Its pathogeny involves various mediators including histamine. Antihistamines, particularly the anti-H1 type can improve a few pruritic disorders. However, they do not compare with specific etiology based therapies. Choosing an antihistamine relies on the balance between efficacy and unwanted side effects which are sometimes serious.

An appraisal of 18-fluorodeoxyglucose positron emission tomography for melanoma staging

BACKGROUND

Positron emission tomography (PET scan) using fluorodeoxyglucose (FDG) is increasingly recognized as a reliable diagnostic method to detect metastases of malignant melanoma (MM).

OBJECTIVE

To compare the diagnostic performance of 18-FDG PET scan to that of conventional imaging.

METHODS

A total of 28 assessments were conducted in 24 patients at risk of metastatic MM.

RESULTS

The diagnostic accuracy was over 80% and similar for PET scan and conventional imaging.

CONCLUSION

Both the specificity and sensitivity of PET scan are high although not perfect. Confrontation of data with anatomical location and clinicopathological findings remains mandatory.

[Bites by terrestrial vertebrates]

Bites by terrestrial vertebrates, reptiles or mammals, represent a special risk in tropical regions. Envenomation is possible by a few lizards and many snakes. For mammals, tissular destructions due to the bite can be severe. Whatever is the offending animal, bites can further become infected by transmitted viruses or bacteria.

[Cutaneous leishmaniasis]

Cutaneous leishmaniasis in its various forms is a frequent disorder in some parts of the world. It can represent an exotic souvenir for the traveller. Four main types of the disease are recognized. They have different prognoses of evolution. The parasite species, the animal reservoir and the geoclimatic environment influence the nature of human leishmaniasis.

Role of antigen-presenting cells in long-term antitumor response based on tumor-derived apoptotic body vaccination

Cellular therapy prospects for cancer are based on the development of T cell response, resulting in efficient tumor rejection and long-term protection. We have previously shown that treatment combining injection of interleukin-2 and tumor-derived apoptotic bodies, but not tumor cell extracts, permits to reject parental tumor in 40% of rats. We observed the implication of antigen-presenting cells (APCs) and tumor-derived apoptotic bodies in the rejection of established peritoneal carcinomatosis. We demonstrated that apoptotic bodies could be efficiently phagocytosed by monocytes, triggering them to an APC phenotype. When using these phagocytosing APCs, derived from peritoneal or blood monocytes, the remission rate reached 80% of rats. However, due to the lack of specific markers of rat monocyte-derived cells, the precise role of APCs, dendritic cells and/or macrophages responsible for this therapeutic improvement remained to be clarified. In order to elucidate this question, we developed an in vivo preventive cellular therapy based on tumor-derived apoptotic bodies, where macrophages were either depleted or activated. We report here that in a preventive antitumoral apoptotic body vaccination that allows survival for 40% of treated rats, the antitumor response was characterized by a specific long-term memory (cured rats rejected a second parental tumor cell challenge). Depletion of resident macrophages with silica or clodronate liposomes appeared to promote apoptotic body vaccination efficiency, increasing the treatment to 66% of success. In this case, FACS analysis showed that peritoneal cells present are essentially immature APCs and freshly recruited NK cells. In contrast, the onset of peritoneal inflammation by thioglycollate, inducing massive recruitment and activation of macrophages, reduced the overall survival, whatever the treatment was. Also, even though the surviving rate was better in silica-treated rats than control, no long-term protection was elicited. Our data suggest that massive inflammation, recruiting numerous activated macrophages, could inhibit tumor antigen presentation by 'professional' APCs having phagocytosed apoptotic bodies, and defavor a specific antitumoral T cell response. Although effective responses were developed against parental tumor cells with silica/apoptotic body treatment, they seemed only partial, limited to primary cytotoxic efficiency. In conclusion, even if macrophages did not appear necessary for a primary response to tumor cells, these cells seemed to be implicated in the establishment of memory and long-term antitumor response.

[Relativity of the management of skin cancers. A plea for synergy between general practitioners and the dermatologist-oncologist]

The clinical diagnosis and treatment of cutaneous cancers represent a frequent situation in cancerology. About one third of all human cancers take their origin from the skin. The general practitioner and the dermatologist-oncologist play the key role in that field of health care.

[Malacoplakia associated with a myelodysplastic syndrome]

Malakoplakia is a rare chronic disease with pleomorphic presentations. It involves many organs, particularly the urinary and gastro-intestinal tracts. It is less common on the skin. Lesions result from impaired phagocytosis of bacteria by macrophages. Malakoplakia is sometimes related to immunodeficiencies. The diagnosis is usually made by histological examination. We report a case associated with a myelodysplastic syndrome.

[Towards obsolete senescence. Everything wanes ... Old age no longer exists!]

Skin ageing is the global result of the influence of numerous factors. Oxidative stress through the intervention of free radicals is one of the most important biological mechanisms solicited by ageing promotors. Prevention of skin senescence relies on several approaches. The main ones are sun protection, tobacco avoidance and limitation of sustained mechanical stress to the skin. Free radical scavengers in adequate combinations might slow down the ageing process. In cosmetology, retinol fulfills its claims. Vitamins E and C, as well as selenium and some plant extracts also show some interest. In the search for increased efficacy, tretinoin is the single topical drug available. Its biologic activity boosts the epidermal growth and the collagen synthesis while inhibiting some metalloproteinases responsible for dermal degradation. Clinical proofs of its efficacy are beyond doubt.

Anisotropy and multiple scattering in thick mammalian tissues

A dual-channel Mach-Zehnder interferometer using heterodyne detection allowed us to measure simultaneously parallel and perpendicular polarization components through various mammalian tissues at a wavelength of lambda = 633 nm. By contrast with liver tissue, squeletic muscles of a few millimeters thickness exhibit strong anisotropic properties that change the direction of the linear polarization of the light. This rotation of the initial plane of polarization is to be distinguished from the depolarization that is due to the multiple light scattering that goes along with large temporal fluctuations. Complementary photos under linearly polarized light illustrate the behavior difference between liver (isotropic medium) and muscle (anisotropic medium).

[Winter skin diseases]

Winter climate is prone to induce cutaneous and systemic alterations mediated by cold. Xerosis due to the impairment of the desquamation process is not rare on the limbs. Chilbain results from reversible alterations of the dermal vasculature. Cold panniculitis is the consequence of lipid crystallization within adipocytes. More dramatic issues occur when cold exposure extends beyond skin. They are represented by frostbite and body hypothermia. Intensity and duration of cold exposure combined with wind speed, altitude and environmental hygrometric value govern the potential type of low temperature-dependent pathology. Ultraviolet irradiation can also induce cutaneous lesions during winter time.

Vascular retardation in dormant growth-stunted malignant melanomas

Progression and metastatic spread of primary cutaneous melanoma (PCM) is largely predicted by the thickness of the primary tumor. However, the accretive or proliferative pattern of growth of PCM is another aspect that might affect the prognosis. We retrieved from our histopathological files 11 superficial spreading PCM which had been documented to show an almost stable size for at least 3 years before excision. The area of the PCM at the skin surface had been measured by planimetry on the excision specimens. Histological sections were used to measure the maximum thickness of the neoplasms. A PCM volume estimate was derived by multiplying the surface area by the thickness of the tumors. In addition, the vessel area was determined beneath and outside the PCM lateral margins on Ulex europaeus agglutinin-1-stained sections using computer-assisted image analysis. Peritumoral vascularity was significantly more developed than at distance of the neoplasms. A significant negative exponential correlation was yielded between the peritumoral vascularity and the PCM volume estimate. Such vascular eclipse might be the cause of clinical PCM dormancy. However, other possible independent mechanisms are not ruled out by the present study.

Antigen-presenting cells that phagocytose apoptotic tumor-derived cells are potent tumor vaccines

We have reported recently that treatments combining injections of apoptotic bodies from tumor cells and interleukin 2 led to tumor regression and induced specific protection. In the present study, we show that tumor-bearing rats were cured with an 80% success rate by injection of antigen-presenting cells (APCs) that had phagocytosed apoptotic bodies derived from poorly immunogenic tumor cells, whereas phagocytic cells exposed to nonapoptotic tumor cell extracts were essentially without effect. In addition, curative vaccination using APCs that had phagocytosed apoptotic bodies generated a tumor-specific cytotoxic T-cell response and long-term protection from parental tumor challenge. Thus, systems using the processing and presentation of antigenic molecules by professional APCs after phagocytosis of apoptotic bodies appear to offer new possibilities for anticancer treatment.

Postural skin colour changes during the corticosteroid blanching assay

OBJECTIVE

To assess the effect of the position of a limb (dependency) on the cutaneous vasoconstrictor (blanching) assay (VCA) using topical corticosteroid preparations.

METHOD

Two studies were performed on the forearms of healthy volunteers using tristimulus reflectance colorimetric assessments. The first one conducted in 60 normal adults aimed at quantifying the range of variation in the skin chromaticity a* when the arm was successively positioned horizontally and vertically, either in the upward or downward direction. In the second study, 16 volunteers were selected according to a weak spontaneous postural dependency of the limb in a* (<2 units). The blanching effect of 0.1% mometasone furoate, 0.1% betamethasone valerate and petrolatum were compared to the colour of an untreated site. Chromaticity a* and the colorimetric variable (DeltatL*(2) + Deltata*(2))(0.5) were measured in time following a 2-hour application.

RESULTS

The postural variations in skin colour varied among subjects. The majority of them (80%) presented a difference in a* higher than 2 units between the upright and downward arm positions. The upright position appeared to be the most sensitive to show significant differences in the VCA. Mometasone furoate exhibited the most prominent effect, significantly higher than betamethasone valerate and controls.

CONCLUSION

The corticosteroid VCA is influenced by the position of the limb. The upright position increases the sensitivity of the test. Mometasone furoate is more potent than betamethasone valerate.