Biomedical subjects
Publications and source records attributed to G Barneon.
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BACKGROUND: Nonablative remodeling has been recently proposed as an alternative to CO2 and Er:YAG resurfacing. OBJECTIVE: To evaluate the efficacy and safety of a 1540 nm Er:glass laser with contact cooling in nonablative skin remodeling, focused on perioral and periorbital rhytides. METHODS: Sixty patients (mean age 47 years), Fitzpatrick skin types I-IV were treated four times over 6-week intervals. Patients were evaluated using digital photographs, histology, ultrasound imaging, and profilometry with silicone imprints in order to quantitate the degree of clinical improvement. RESULTS: All subjects reported subjective improvement in the quality and visual aspect of their skin. This was confirmed by a 40.2% reduction of anisotropy (P <.001) 6 weeks after the fourth treatment. Ultrasound imaging demonstrated a 17% increase of dermis thickness (P <.005). Biopsy specimens showed evidence of new collagen formation. CONCLUSION: This study has clearly demonstrated that irradiation with 1540 nm Er:glass laser can lead to new collagen formation, dermis thickening, reduction of anisotropy of the skin, and clinical improvements. The lack of adverse effects confirmed that this 1540 nm laser emitting in a pulsed mode coupled with an efficient cooling system is safe.
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INTRODUCTION/OBJECTIVE: This study aimed to evaluate the safety and efficacy of a 3.5 ms Nd:YAG laser for the removal of hair in subjects with Fitzpatrick skin types I-IV. Thanks to a pulse shorter than the hair Thermal Relaxation time (TRT), photothermolysis was thus achieved. METHODS: This study assessed the percentage of hair reduction at 1 month and at 3 months after a single Nd:YAG laser treatment (Athos; Quantel Médical, France); 3.5 ms pulse, single shot to 3 Hz, a maximum fluence of 80 J/cm2, 4 mm spot, no cooling system, no anaesthesia. The treatment sites consisted of three adjacent squares (optimum fluence, no treatment, -20% optimum fluence). Computerized hair counting was realized on digital pictures. The phototype, pain, side effects and patient's satisfaction were noted. Biopsies were performed 15 min after treatment. The enrolment consisted of 17 women, 22-60 years old, phototypes I-IV, with a follow-up at 1 month and 3 months of 25 sites. RESULTS: Counting at 1 month and at 3 months revealed a significant hair reduction compared with the control sites: 60% at 1 month (P < 0.001) and 24% at 3 months (P < 0.05) for optimal fluence (25-80 J/cm2), compared with 31% and 0% on the control sites; values similar to those published for Nd:YAG or diode lasers. There were no adverse effects at all. Biopsies showed lesions from necrosis coagulation of the root sheaths and hair disruption to isolated apoptotic cells in the outer root sheath, depending on the fluence applied. CONCLUSION: Results from this study show that the Athos Nd:YAG is efficient and safe for removing pigmented hair in phototypes I-IV.
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Necrotizing livedo reticularis is an infrequent, life-threatening complication of chronic renal failure. Since Selye's studies in 1962, calciphylaxis, i.e. acute calcium deposition in tissue, is considered the main pathomechanism, especially because hyperparathyroidism are very frequently present. However, other etiological and/or triggering factors, such as coagulation disorders, direct cellular toxicity of parathormone or calcium on endothelium, might be involved, acting perhaps in a cumulative way. We report a case with a circulating anticoagulant which supports this hypothesis.
Acquired progressive lymphangioma (APL) is a rare, benign proliferation of lymphatic capillary origin, which is characterized histologically by dermal vascular channels and a 'dissection of collagen' appearance. We describe a 30-year-old patient with an extensive, refractory APL on the right breast, which slowly developed over a period of 23 years. Pathologists and dermatologists should be aware of this entity, as early surgical treatment may be totally curative when the lesion is limited in size.
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The authors report the case of a tetralogy of Fallot associated with a neuroblastoma secreting large quantities of noradrenaline. Anoxic decompensation of the tetralogy of Fallot occurred early at the age of 4 months with cyanotic crises associated with an impression of abdominal pain. A systemic-pulmonary anastomosis was performed and the cyanosis regressed but the crises persisted and investigations showed the presence of a neuroblastoma. The tumour was treated by surgery and chemotherapy and has not recurred after 2 years' follow-up. Complete repair of the tetralogy of Fallot was performed secondarily at the age of 2. In this case, the high concentration of circulating catecholamines was probably a factor of early decompensation of the tetralogy of Fallot by infundibular spasm. A review of the literature revealed 26 cases of cardiac disease with a peripheral neurogenic tumour. Two pathogenic mechanisms are suggested: an embryological abnormality of cardiac cell migration from the neural crest and chronic stimulation of neuroblastic cells by chronic hypoxia.
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Mast cells and histamine-mediated reactions may be altered in patients with cancer. In an attempt to characterize the possible skin defects in patients with cancer, we tested 22 patients suffering from lung cancers, 30 from breast cancers, and 30 age-matched normal individuals, using several compounds, in investigating the pathophysiology of the skin response. Histamine hydrochloride (10 and 100 mg/ml) and codeine phosphate (9%) were tested by prick test. Substance P (50 and 500 ng per injection site), phentolamine (20 micrograms per injection site), and carbachol (1 microgram per injection site) were tested by intradermal skin tests. Skin mast cells were also microscopically examined in 10 patients with lung cancer, five with breast cancer, and 10 normal subjects. The mean wheal sizes induced by all the tested substances were similar in patients with cancer and chronic bronchitis and in normal individuals. The flare to histamine, codeine phosphate, and substance P was completely abolished in 7/22 patients with lung cancer, but the lack of flare was not related to the age of the patients, nor to the staging of cancer, nor to metastasis. The mean numbers of alcian blue-stained or toluidine blue-stained positive mast cells were similar in normal subjects and in subjects with cancer. This study does not confirm the skin hyporeactivity of patients with cancer.
Alveolar macrophages (AM) are among the cells involved in the bronchial inflammation of asthma. It has been shown that AM are a heterogeneous cell population in normal subjects. The heterogeneity of AM from 36 asthmatic patients and 23 normal subjects was studied using Percoll density fractionation. AM recovered from asthmatic patients are mainly in the lower density fractions (1.03 and 1.04 g/ml), whereas AM from normal subjects are in the higher density fractions (1.05 and 1.07 g/ml). Electron microscopic studies showed that low density AM of both asthmatic and normal subjects appear to have morphologic characteristics of activated cells by comparison with high density AM that present characteristics of quiescent cells in both asthmatic and normal subjects. The functional activity of AM fractions of asthmatic and control subjects was assessed using the release of the oxygen free radicals induced by opsonized zymosan and TxB2 generation by A23187. There was no difference between the five fractions of asthmatic or control subjects with regard to oxygen species release. The TxB2 generation was increased in the low density AM from asthmatics when compared with the same fractions of normal subjects. The hypodense cells produced less TxB2 than did cells of higher density in both asthmatic and normal subjects. The density of AM was correlated with the recent instability of the asthma but not with the severity of it. This study shows that AM from asthmatic subjects, when compared with those from control subjects, are heterogeneous, hypodense cells and that they predominate. Hypodense AM did not appear to be hyperresponsive in vitro and may have been already committed into the airways.
We report the effects of induced ultrasonic lesions on the sciatic nerve of the rat. Using different level of intensity (5 to 35%) and time exposure (5 to 60 seconds) for each application, we study the effects by action potential recording, microphotography and histological study. The nerve remains unaltered for low intensity (5 to 10%) until a time exposure of 20 seconds. Beyond that level, a progressive severity of the lesion is documented from oedema to contusion. A safe use of the surgical ultrasonic aspiration in the vicinity of nerves and roots must have a low intensity level, reducing the risks of direct contact between nerve and sonoprobe.