[Optimization of the healing process after laser procedure, except photorejuvenation]. / Optimisation et gestion de la cicatrisation après acte laser, en dehors du photo-rajeunissement.

The use of Lasers in dermatology implies a crucial follow-up in order to optimize the final result and avoid any side effects. With the use of ablative laser devices, the initial phase is characterized by the development of crusts. These crusts necessitate the application of sterile ointments (regularly repeated throughout the day) as well as an antibiotic ointment two times a day. In a second step, comes a secondary inflammatory state, in the dermis, which is generally observed at the outset of all other laser treatments. The main purpose is to avoid it from being too sustained over time, but also to prevent the occurrence of post inflammatory hyperpigmentation. Obviously, a solar eviction will be strongly recommended. The risk being maximized with dark phototypes, the choice of the Laser, as well as its specific parameters will be specific and decisive.

[Role of laser in the treatment of rosacea]. / Place du laser dans le traitement de la rosacée.

The role of vascular lasers in the treatment of rosacea is important. Despite the relative low number of studies using an excellent methodology, one can consider that it is un-discussable. Two lasers are mainly used: pulsed dye lasers and KTP lasers. But the main discussion is the choice of the principle of treatment, related to the pulse duration, photocoagulation or selective photothermolysis. Photothermolysis is more effective, mainly on thintelangiectasias and diffuse erythrosis, but it induces purpura, and certain patients do not agree with those side effects. Nd-Yag lasers must be carefully used, because they can induce facial atrophic scars. They are rarely effective, with long lasting results, on flushes, but they improve the quality of life of patients. Their main limit is the logical lack of efficacy on the inflammatory lesions, even if patients often notice an improvement of the disease. Recurrences are common after several years of follow up.

Treatment of port wine stains with pulsed dye laser and topical timolol: a multicenter randomized controlled trial.

BACKGROUND: Neoangiogenesis occurs within days following laser treatment of port wine stains (PWS), and plays a central role in treatment failures. Topical use of timolol can significantly reduce the production of vascular endothelial growth factor in vitro, and in animal models. OBJECTIVES: The aim of this study was to assess the efficacy of topical timolol in combination with pulsed dye laser (PDL) treatment, compared with PDL alone, for treating PWS. METHODS: This was a prospective multicenter controlled trial performed in children with PWS of the face who had not previously received laser treatment. After randomization, one group was treated with PDL alone, and the other with PDL followed by twice daily applications of timolol gel. Three laser sessions were performed at 1-month intervals with fixed parameters. The evaluation was performed on standardized pictures by two independent physicians blinded to the treatment received. The primary endpoint was marked or complete improvement of the PWS [Investigator Global Assessment (IGA) 3 or 4] 1 month after the third session. RESULTS: Twenty-two children were included. Two patients were lost to follow-up. There was no difference in the success rate between the two groups (IGA 3 or 4 observed in one of 10 patients and two of 12 patients, for PDL alone, and for PDL associated with topical timolol, respectively; P = 1·0). No side-effect related to the application of topical timolol was observed. CONCLUSIONS: The addition of timolol gel for preventing neoangiogenesis failed to significantly improve the efficacy of PDL treatment of PWS.

[Finger onychomycosis due to Candida tropicalis: short-pulsed Nd:YAG laser therapy]. / Traitement d'une onychomycose digitale à Candida tropicalis par laser Nd:Yag Short Pulse.

BACKGROUND: Treatment options for onychomycosis are numerous but of limited efficacy, potentially dangerous and/or relatively restrictive. PATIENTS AND METHODS: We describe the first case of Candida tropicalis onychomycosis resistant to standard topical treatments successfully treated with four sessions of Nd:YAG laser in Short Pulse mode. The efficacy of treatment was verified at 3 months via a negative control sample and was maintained for at least 6 months. DISCUSSION: Nd:YAG laser is a versatile type of laser widely used in dermatology. Its mode of action in the treatment of onychomycosis may consist of a thermal effect that is non-specific but differentiates between healthy nail and diseased nail, which respond differently to impact. The main interest of this case is in helping to pave the way for a new type of treatment for onychomycosis.

[Lipolysis lasers]. / Lasers de lipolyse.

We use lipolysis lasers for around five years. The principle of those lasers is that, for some wavelengths, the fat, located in the adipocytes reacts as a chromophor. In order to allow the direct exposure of the adipocytes to the optical fiber (around 1mm diameter), this has to be inserted in the hypodermis, then move back and forth inside the treated areas. The theorical benefits, compared to the liposuction procedures are related to the fact that the thermal effect of the laser emission allows to avoid laxity, sometimes observed after a liposuction. If we consider the first publications related to this emerging procedure, the profile of tolerance seems good, and even possibly better than the liposuctions. Nevertheless, this procedure with lasers is still a surgical procedure, exposing theorically to the side effects related in and after each surgery: infections, ecchymosis... Recently, some cases of severe side effects (infection of the skin, and necrosis) have been reported. They seem to be related to a homogeneous distribution of the energy inducing an excessive thermal injury. Some new improvements, with the last generation lasers, could allow us to avoid, or at least to dramatically reduce those side effects. The efficacy of those lasers is visibly satisfying; the key question is to precise the optimal modalities of use : in a surgery room, after an optimal training, with the last generation lasers?

[Fractional photo-thermolysis by laser Fraxel as an adjuvant for facial surgical rejuvenation]. / Le relissage fractionné par laser Fraxel: un traitement complémentaire possible pour la chirurgie du rajeunissement facial.

The fractional resurfacing (Fraxel laser) is a new procedure for facial and extrafacial rejuvenation. His claim is obtain a great efficacy on wrinkles, close to those of the CO(2) and erbium lasers, but without their risks and long lasting down time. We use a scanner, able to create multiple (around 2000 to 3000/cm(2)) 70-150 microns diameter microthermal zones surrounded by islands of viable tissue. The reepithelialization is complete in a day, but there is a collagen denaturization in the dermis, between 300-750 microns like after a traditional resurfacing. At each session, around 25% of the dermis are treated. 4 treatments are performed with a 1 to 2 weeks interval. We report our comprehensive results since we began in December 2004. At the time of the abstract, 600 sessions were performed (150 Patients). A visible reduction of wrinkles is observed anytime, with improvement of the texture of the skin, and in the same time, a dramatic improvement of the pigmented lesions. About tolerance, no severe side effects or dyschromia were noticed. We observed two case of limited erosion, (one of the first patients) due to a practical problem (bulk heating). The average erythema duration is 2 days. On the face, a 2-4 days edema occurs in many of the patients. Fraxel laser treatment is not designed as a substitute for surgical skin tightening such as facelift. Therefore, the fractional resurfacing is safe and effective for a visible reduction of wrinkles and appears as a very interesting treatment in association with face lift to rejuvenate the face.

[Indications for medical lasers in dermatology]. / Indications des lasers médicaux en dermatologie.

FOUR CATEGORIES OF LASERS ARE USED IN DERMATOLOGY: These are vascular, depigmentation, depilatory or resurfacing or vaporization lasers. Today, there are more potential or suggested indications than good methodological studies that confirm these indications. Nevertheless, there are indisputable indications for these lasers. VASCULAR LASERS: They are indicated in the treatment of capillary nevus in adults and children and, with pulsed dye lasers, infants can be treated within the first weeks of life. Another indication for vascular lasers is treatment of Stage II rosacea, i.e., at the stage of telangiectasic erythrosis or couperose. Other indications include radiodermatitis, ulcerated hemangioma and erythrosis of the neck. DEPILATORY LASERS: Treatment of patients with pale phototype and dark hairs appears possible. However, around 4 to 6 sessions are required to obtain significant lasting hair removal. DEPIGMENTATION LASERS: The best indications are the removal of tattoos, Ota's nevus and, to a lesser degree, liver spots and Becker's nevus. Melasma and chloasma are not indications or exeresis of nevo-cellular nevi using this technique, since no histological control is possible. PULSED VAPORIZATION LASERS (CO2 OR ERBIUM LASER): They permit dermabrasion in the treatment of verrucous harmatoma, extensive benign superficial dermo-epidermal lesions and the esthetic treatment of non-muscular wrinkles, i.e., excepting wrinkles of the forehead and nasal sulcus. Continuous CO2 lasers destroy small dermo-epidermal lesions. They are particularly indicated for profuse lesions, in which there is a risk of hemorrhage or when direct contact should be avoided because of potential HIV infection. CONCLUSION: There are many potential indications, but a consensus has only been reached on those mentioned. The others remain to be confirmed.

Treatment of gunpowder traumatic tattoo by Q-switched Nd:YAG laser: an unusual adverse effect.

BACKGROUND: The Q-switched Nd:YAG laser can completely eliminate traumatic tattoos. OBJECTIVE: We report the results of the unsuccessful removal of traumatic tattoos among three patients with dermal inclusions of gunpowder who were shot at close range. METHODS: Treatment was tried in each patient with a Q-switched Nd:YAG laser at a medium fluence (4-6 J/cm2). RESULTS: During treatment of our patients, each pulse provoked sparks and the immediate formation of bleeding trans- epidermal pits. After the healing process was completed, we observed poxlike scars and the spreading of pigments in the skin around the initial points of the tattoo. CONCLUSION: We hypothesize that the rapid transfer of high-energy pulses to powder particles creates microexplosions of these fragments resulting in cavitation and provoking transepidermal holes and subsequent scars. This adverse effect was only produced if the tattoo resulted from gun powder being shot at a short distance from the skin.

A human extrastriate area functionally homologous to macaque V4.

Extrastriate area V4 is crucial for intermediate form vision and visual attention in nonhuman primates. Human neuroimaging suggests that an area in the lingual sulcus/fusiform gyrus may correspond to ventral V4 (V4v). We studied a human neurological patient, AR, with a putative V4v lesion. The lesion does not affect early visual processing (luminance, orientation, and motion perception). However, it does impair hue perception, intermediate form vision, and visual attention in the upper contralateral visual field. Form deficits occur during discrimination of illusory borders, Glass patterns, curvature, and non-Cartesian patterns. Attention deficits occur during discrimination of the relative positions of object parts, detection of low-salience targets, and orientation discrimination in the presence of distractors. This pattern of deficits is consistent with the known properties of area V4 in nonhuman primates, indicating that AR's lesion affects a cortical region functionally homologous to macaque V4.

Object recognition: seeing us seeing shapes.

Our understanding of the neural basis of object recognition is based primarily on work with non-human primates. The problem has recently been addressed in humans using functional magnetic resonance imaging; new results indicate that the lateral occipital complex plays an important role in human object recognition.

How the owl resolves auditory coding ambiguity.

The barn owl (Tyto alba) uses interaural time difference (ITD) cues to localize sounds in the horizontal plane. Low-order binaural auditory neurons with sharp frequency tuning act as narrow-band coincidence detectors; such neurons respond equally well to sounds with a particular ITD and its phase equivalents and are said to be phase ambiguous. Higher-order neurons with broad frequency tuning are unambiguously selective for single ITDs in response to broad-band sounds and show little or no response to phase equivalents. Selectivity for single ITDs is thought to arise from the convergence of parallel, narrow-band frequency channels that originate in the cochlea. ITD tuning to variable bandwidth stimuli was measured in higher-order neurons of the owl's inferior colliculus to examine the rules that govern the relationship between frequency channel convergence and the resolution of phase ambiguity. Ambiguity decreased as stimulus bandwidth increased, reaching a minimum at 2-3 kHz. Two independent mechanisms appear to contribute to the elimination of ambiguity: one suppressive and one facilitative. The integration of information carried by parallel, distributed processing channels is a common theme of sensory processing that spans both modality and species boundaries. The principles underlying the resolution of phase ambiguity and frequency channel convergence in the owl may have implications for other sensory systems, such as electrolocation in electric fish and the computation of binocular disparity in the avian and mammalian visual systems.

[Cyclosporine and psoriasis]. / Ciclosporine et psoriasis.

Cyclosporin has proved efficacious in severe and resistant psoriasis. When moderate doses are administered (below 5 mg/kg/day) satisfactory clinical results are obtained at the cost of side-effects that can be controlled, since they are dose-dependent and regress when dosage is reduced. The most important of these side-effects are arterial hypertension and nephrotoxicity due to vasoconstriction of glomerular arteries. It is therefore essential to use low doses (3 mg/kg/day initially) and to measure blood pressure and creatinine levels regularly. This being known, there is no doubt that cyclosporin constitutes a step forward in the treatment of severe psoriasis.

Mammographic localization and biopsy: the experience of a gynecologic oncology group.

From 1976 through 1986, two hundred eighty or 9% of all breast biopsies performed by a private gynecologic oncology group were for mammographically suspicious but occult breast lesions. Sixteen percent were found to be malignant. There has been improvement in mammographic techniques, and localization procedures have evolved to the current use of hooked-wire needles, which allow for the excision of smaller amounts of tissue and use of outpatient surgery facilities. Recently, the cancers encountered have been more often carcinoma in situ rather than invasive lesions. With the current increase in mammographic screening, there needs to be a continuing evolution in diagnostic modalities.