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Biomedical subjects

Serge Mordon

Publications and source records attributed to Serge Mordon.

At least 19 recordsLinked to original sources
PubMed2006

Facial rejuvenation and light: our personal experience.

The treatment of ageing skin remains a very hot topic, and many systems have been reported as having varying degrees of success. Nonablative lasers were developed to avoid the problematic and uncomfortable sequelae following laser ablative resurfacing, and while there was no downtime, there was also poor patient satisfaction. The same was true of the intense pulsed light systems. The use of different modalities in various combinations was found to offer much better results, however, such as a 595-nm pulsed dye laser followed by a 1,450-nm diode laser, and so on, all used at subablative thresholds. The recent entry of blue and infrared tunable plasma light and light-emitting diodes into the skin rejuvenation arena has attracted a great deal of attention. The authors suggest that no single modality can accomplish all the complex events required for effective skin rejuvenation, suggest that combination phototherapy is the best approach combined with an adjunctive epidermal care regimen, and demonstrate their development of this methodology.

Aging↗
PubMed2006

Monitoring of bactericidal action of laser by in vivo imaging of bioluminescent E. coli in a cutaneous wound infection.

The worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. This study aimed to evaluate the bactericidal action of an 810-nm diode laser in a cutaneous wound infection. An Escherichia coli strain was transformed with a shuttle vector (pRB474) containing firefly luciferase gene from Photinus pyralis resulting in a bioluminescent phenotype. Because firefly luciferase is an enzyme and as such is prone to inactivation at elevated temperature, the first phase has consisted in evaluating in vitro the effect of temperature elevation (30, 40, 50, and 60 degrees C for 2 min) on bacteria bioluminescence. The second phase was performed in vivo. Two full-thickness circular, 14-mm diameter wounds (control and laser-irradiated) were induced on rats. Wound infection was carried out using a suspension (50 microl PBS) containing 5 x 10(7) cells of bioluminescent E. coli (10(9) cells/ml). Thirty minutes later, light irradiation was performed with an 810-nm diode laser (P = 10 W, psi = 1.4 cm, fluence: 130, 195, and 260 J/cm2). Temperature was measured within each wound with a noncontact infrared thermometer. Light emission of the bioluminescent bacteria was monitored in vivo by a bioluminescence imaging system before and at 4, 8, 24, and 48 h after laser irradiation. In vitro, bacteria bioluminescence is not affected when temperature is maintained at 50 degrees C for 2 min. In vivo, bioluminescence imaging showed that at 4 h, the viability of E. coli was reduced when compared to the control (CTRL) group (p < 0.01). This observation was confirmed at 8 h (p < 0.001), at 24 h (p < 0.001), and finally at 48 h (p < 0.001). Loss of viability of E. coli depends on laser fluence. At 48 h, bioluminescent bacteria were not detected (100% loss of viability) in the wound irradiated at 260 J/cm2. For this fluence, the temperature reached 45 degrees C at the end of the irradiation. This study confirms previous observations on the bactericidal effect of diode lasers. Because a progressive desiccation of the superficial dermis is usually observed when using laser irradiation, the hypothesis that laser irradiation dries out the wound making the wound an inhospitable place for bacteria is much more relevant than a direct effect of infrared light on chromophores inside bacteria. This is confirmed by the fact that in this latter case, one would expect an immediate drop in luminescence followed by an increase as the surviving bacteria started to divide and repopulate the wound. However, the exact mechanism deserves further studies. This study points out the advantage of using bioluminescence imaging to evaluate laser for the treatment of acute infections in vivo, nondestructively, and noninvasively.

Animals↗
PubMed2006

Using white light during photodynamic therapy: visualization only or treatment?

BACKGROUND: Photodynamic therapy (PDT) involves selective uptake and retention of a photosensitizer in a tumor, followed by irradiation with light (usually a 630 nm diode laser), initiating tumor necrosis through formation of oxidized products or singlet oxygen. Successful PDT of early cancers of the esophagus and of Barrett's esophagus with severe dysplasia has been reported. However, side effects (edema, stricture, etc.) and treatment failure have been observed. This study aims to evaluate the possible photodynamic effect induced by illumination from the endoscope on the PDT effect, since a photon emitted to see the lesion can potentially be a photon to treat it! MATERIALS AND METHODS: Two fiber endoscopes (Olympus GIFPQ20 and Pentax FG34X) and one videoendoscope (Olympus GIFQ140) were evaluated. Output power, irradiance and emission spectrum were measured. Using the molar extinction coefficient of Photofrin and optical coefficients of the esophagus, the relative photodynamic reaction yield, determined as a function of depth, was compared with that obtained with a 630 nm diode laser. RESULTS: The irradiance at 1 and 2 cm was, respectively, 18.4 and 4.6 mW/cm (Pentax FG34X), 10.6 and 2.65 mW/cm (Olympus GIFPQ20), and 2.7 and 3.2 mW/cm (Olympus GIFQ140). The highest irradiance could lead to a relative photodynamic reaction yield at the surface of the esophagus similar to (Olympus GIFPQ20) or greater than (Pentax FG34X) that obtained using a diode laser alone. CONCLUSIONS: Our results could explain side effects sometimes observed when performing PDT. 'Endoscopic' illumination, however, could also represent an interesting alternative to the 630 nm diode laser. When using white light, superficial efficacy of PDT could be reinforced and transmural necrosis leading to perforation or stenoses reduced, since there is less red light in depth compared with a diode laser.

Absorption↗
PubMed2006

Use of nonthermal blue (405- to 420-nm) and near-infrared light (850- to 900-nm) dual-wavelength system in combination with glycolic acid peels and topical vitamin C for skin photorejuvenation.

BACKGROUND AND OBJECTIVES: A major cause of skin aging is a chronic microinflammation created by environmental conditions and ultraviolet exposures. The hand-free application on the skin of a new intense light combining a narrowband blue-light (405- to 420-nm) antiinflammatory emission and a near-infrared (850- to 890-nm) emission inducing self-defense mechanisms provides a new component to photorejuvenation and antiaging treatment protocols. STUDY DESIGN: An innovative skin rejuvenation schedule is presented in this study. It includes skin exposure to the light, with concomitant glycolic peels and daily vitamin C cream regimen for group A and only topical vitamin C cream and glycolic peels for control group B. RESULTS: Results show a significant improvement on pore size, rhytids, and radiance in group A. Conversely no improvement is noticed in group B except for a brief increase of skin radiance. Mechanisms of action of that specific light source are discussed. CONCLUSION: The exposure to this device can clinically enhance conventional antiaging protocols in skin rejuvenation.

Administration, Topical↗
PubMed2005

Dynamics of temperature dependent modifications of blood in the near-infrared.

BACKGROUND AND OBJECTIVES: Laser irradiation induces blood coagulation by heating of blood components. It is a complex phenomenon which encompasses a variety of processes, such as cell shape modification, cell membrane rupture, protein denaturation, aggregation, and finally blood gelation. An in vitro study was performed to investigate heating temperatures leading to transformation of blood and to have a better understanding of the dynamics of temperature dependent modifications of blood in the near-infrared. STUDY DESIGN/MATERIALS AND METHODS: Slow heating of whole blood and hemolized blood was performed using a specific optical chamber. Eight hundred and five and 940 nm light transmission of blood was measured as a function of time during heating at various temperatures (60-75 degrees C). RESULTS: During heating of whole blood, three phases were clearly identified. For hemolized blood, only phase 3 was present. For whole blood, the duration of each phase was correlated to blood temperature. A temporary increase of transmission was observed during heating with a maximum at 65 degrees C. The analysis of the dynamics of temperature dependent modifications of blood are consistent with cell shape modification, denaturation, and aggregation of blood, resulting in the formation of an aqueous gel-matrix. CONCLUSIONS: "Slow" vessel heating which is now proposed as the optimal mechanism for permanent vessel closure should be reconsidered in terms of our results. In that particular case, the optical coefficients of blood could be different from those expected. In case of a large blood vessel, this could be an advantage since a "temporary" higher transmission of light could lead to a more homogeneous heating of the blood vessel. In case of a small blood vessel, this phenomenon could lead to a collateral damage of the skin.

Blood↗
PubMed2005

Nonablative remodeling with a 1,540 nm erbium:glass laser.

BACKGROUND: Nonablative remodeling has recently been proposed as a new antiaging treatment with no downtime. This technique could greatly benefit the increasing numbers of patients who are looking for new and efficient techniques, with a minimum of discomfort. MATERIALS: AND METHODS. The 1.54 microm wavelength has been proposed for this application because this wavelength is well absorbed by water yet virtually not at all by melanin, allowing deep penetration into the skin. To protect the epidermis during laser irradiation, a cooling system (+5 degrees C) uses a sapphire window (purified tetrafluoroethane circulates in a pipe around the sapphire) directly applied to the skin through which the laser pulse may be fired. RESULTS: Several clinical trials have been published and have demonstrated that clinical improvement was correlated with data from ultrasound imaging, histology, and profilometry. A recent trial on the forehead and neck yielded additional data on elasticity measured by echorheometry. CONCLUSIONS: The 1.54 microm laser is safe and effective for remodeling in all of these published studies. Remodeling requires months to achieve its goal, and the kind of improvement that can be expected should be explained to the patient. Long-term follow-up showed that the improvement increased after each treatment and lasted for months after the final session.

Erbium↗
PubMed2004

Peroxynitrite decomposition catalysts prevent myocardial dysfunction and inflammation in endotoxemic rats.

OBJECTIVES: The aim of this study was to test whether peroxynitrite neutralizers would reduce peroxynitrite accumulation and improve myocardial contractile dysfunction and inflammation in endotoxin-treated rats. BACKGROUND: Release of endogenous proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha in response to endotoxin is responsible for the production of large amounts of nitric oxide (NO), which may exert detrimental effects on the myocardium in animal models, isolated hearts, and isolated cardiac myocytes. Recent studies have indicated that many of the deleterious effects of NO are mediated by peroxynitrite, a powerful oxidant generated from a fast diffusion-limited reaction of NO and superoxide anion. METHODS: We studied the effects of peroxynitrite neutralizers, such as mercaptoethylguanidine (MEG) sodium succinate (10 mg/kg) and 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrinato iron (III) (FeTPPS) (30 mg/kg) on peroxynitrite accumulation, in vivo endothelial cell-leukocyte activation on the mesenteric venule, and myocardial contractile dysfunction and inflammation in a model of sepsis induced by injection of endotoxin (10 mg/kg) in rats. RESULTS: Mercaptoethylguanidine sodium succinate and FeTPPS largely prevented the accumulation of peroxynitrite as measured by plasma rhodamine fluorescence and heart nitrotyrosine staining. Interestingly, MEG sodium succinate and FeTPPS improved endotoxin-induced myocardial contractile dysfunction, which was associated with reduced degradation of nuclear factor kappa B inhibitory protein I-kappa-B, plasma TNF-alpha levels, and microvascular endothelial cell-leukocyte activation. CONCLUSIONS: These observations suggest that the beneficial effects of MEG and FeTPPS on endotoxin-induced myocardial contractile dysfunction could be related to the unique effects of these compounds on cardiovascular inflammation processes.

Animals↗
PubMed2004

Comparison and sequential study of long pulsed Nd:YAG 1,064 nm laser and sclerotherapy in leg telangiectasias treatment.

BACKGROUND AND OBJECTIVES: Millisecond pulsed 1,064 nm Nd:YAG lasers have been developed for the treatment of leg telangiectasias. To date there have been very few side by side comparison studies of laser versus the gold standard sclerotherapy in treating small leg veins. This study aims to compare a long pulsed Nd:YAG laser with contact cooling to sclerotherapy for treating small diameter leg telangiectasias by evaluating objective and subjective clinical effects. STUDY DESIGN/PATIENTS AND METHODS: Fourteen patients were selected with leg telangiectasias ranging from 0.5 to 2 mm at four comparable sites. One site was treated with long pulsed Nd:YAG alone, the second received sclerotherapy alone, the third laser then sclerotherapy, and the last one sclerotherapy then laser. The patients were followed up at 3 months after the last treatment. Photographs were taken pre-operatively and at 3 months after the last session. They were used for objective and comparative analysis. Statistical analysis was performed using Friedman's test controlling for subject. RESULTS: Improvement was tabulated from the photographic assessment on an improvement scale from 0 (no change) to 4 (greater than 75% clearing). There were clinical improvements in the laser group than sclerotherapy without statistical significance. Side effects were minimal and included hyperpigmentation. CONCLUSIONS: This pilot study demonstrates that the Smartepil LS long pulse Nd:YAG 1,064 nm laser can yield results similar to sclerotherapy in the treatment of small leg telangiectasias. Combination of both methods could increase response to treatment.

Case-Control Studies↗
PubMed2004

Laser cartilage reshaping in an in vivo rabbit model using a 1.54 microm Er:Glass laser.

BACKGROUND AND OBJECTIVES: The potential applications for facial laser cartilage reshaping (LCR) have generated increasing clinical interest. This study aimed to evaluate in vivo LCR of the rabbit ear using a 1.54 micro m Er:Glass laser in combination with contact cooling. STUDY DESIGN/MATERIALS AND METHODS: LCR was performed in vivo on 12 rabbit ears using a 1.54 micro m Er:Glass laser (Aramis, Quantel Medical, Clermont Ferrand, France) connected to a 4 mm chilled (+5 degrees C) handpiece placed in contact to the skin. Ear curvature was predetermined using a perforated cylindrical guide also used to standardize laser beam delivery. The treatment consisted of 15 spots (3 millisecond, 7 pulses, 12 J/cm(2), 2 Hz, 84/cm(2) cumulative fluence) applied on 10 contiguous parallel rows along the ear. After irradiation, the aluminum jig was replaced by a holder (10 mm diameter plastic tube) maintaining the curvature. This holder was secured with sutures and covered by an adhesive gauze bandage dressing to keep new form during 7 days. In order to assess thermal damage, biopsies were taken on irradiated areas and 1 week, 3 weeks and 6 weeks and studied using haematoxylin-erythrosin-safran (HES) and orcein staining and PCNA to detect cells in cycle. RESULTS: Using the laser with the parameters given above, no immediate visible effects were observed on the skin (no swelling, no bleaching). There were also no late visible side effects like crusting, or blistering. The laser treatment produced changes in the shape of every ear after the dressing was removed. A slight tendency to recover its initial shape was observed for each ear. However, the curvature was stabilized after 10 days and the average shape retention was 64+/-4% at 6 weeks, with a curvature radius of 7.25+/-0.75 mm, instead of 5 mm initially. Histological examination of the laser irradiated side at 1 week showed an intact epidermis. A reduced inflammation process was seen in the dermis. A modification of half of the layer of cartilage was observed at the opposite side where the laser irradiation was applied and proliferative cells were detected inside. At 3 weeks, an important chondroblastic proliferation was observed around the area of contracted cartilage. At 6 weeks, significant thickening of the cartilage layer was observed (from 300 to 490 micro m) and new chondrocytes were clearly seen. CONCLUSIONS: Rabbit ear cartilage can be reshaped with an Er:Glass laser. This technique could offer exciting possibilities that may help patients whose cartilage-lined joints have been affected by disease or trauma. This technique could be certainly utilized to correct alar cartilage deformities and septum deviation of cleft lips.

Animals↗
PubMed2004

Ultrasound imaging demonstration of the improvement of non-ablative laser remodeling by concomitant daily topical application of 0.05% retinaldehyde.

BACKGROUND: Retinaldehyde has been proven to be effective in the reduction of facial wrinkles. It has also demonstrated its usefulness when used before and after laser skin resurfacing. OBJECTIVE: A monocentric, comparative, randomized, double-blind study was performed to evaluate the efficacy of retinaldehyde versus excipient in combination with non-ablative laser remodeling treatment. METHODS: A total of 16 female patients (mean age 45 years) were enrolled for neck line and forehead rhytid treatment. They were randomly assigned into two groups. The RAL group (eight patients) was treated with a non-ablative laser (1540 nm Er:glass, 10 J/cm2 per pulse, three pulses, 2 Hz repetition rate, 4 mm spot, +5 degrees C cooling) and daily topical application of 0.05% retinaldehyde immediately after the first laser treatment and up to 3 months after the fifth treatment. The CTRL group (eight patients) was treated under similar conditions, except with a daily application of excipient. The thickness of the skin (forehead and neck) was measured by ultrasound imaging before the first treatment, 1 month after the third treatment, 1 month after the fifth treatment and 3 months after the fifth treatment. RESULTS: An increase of dermal thickness was observed for all patients treated by laser (groups RAL and CTRL) on the forehead and neck. However, the increase was greater for the RAL group (retinaldehyde) when compared with the CTRL group (excipient). Three months after the fifth treatment, the increase in dermal thickness (%) was, respectively, 5.27 versus 1.13 for the forehead and 10.54 versus 3.57 for the neck. The difference between groups was statistically significant in favor of the retinaldehyde group for the forehead (p<0.05) and of limited significance for the neck (p=0.08). CONCLUSION: When considering the reduced number of patients in each group, the statistical analysis demonstrates an evident advantage of using retinaldehyde versus excipient. This study demonstrates that irradiation with a 1540 nm Er:glass laser can be potentiated with concomitant daily topical application of 0.05% retinaldehyde.

Administration, Topical↗
PubMed2004

A 35-month profilometric and clinical evaluation of non-ablative remodeling using a 1540-nm Er:glass laser.

BACKGROUND/OBJECTIVE: As remodeling is getting more popular with patients, long-term studies are becoming necessary. The aim of this 35-month clinical study was to evaluate the long-term benefits obtained using a 1540-nm Er:glass laser for non-ablative remodeling of perioral and periorbital rhytids. The role of maintenance treatments was also investigated. STUDY DESIGN/METHODS: Eleven women with periorbital and perioral rhytids underwent a series of five treatments at 6-week intervals with an Er:glass laser. Five patients subsequently received two maintenance retreatments and six did not. The maintenance treatments were performed at 14 and 20 months. Silicone imprints were performed to measure anisotropy before treatment, at 6 months, at 14 months and at 35 months. Patient self-evaluation/questionnaire was also done to assess adverse effects and subjective clinical improvement. RESULTS: For all 11 patients, the percentage of anisotropy reduction was 41.21% at 6 months, 51.76% at 14 months and 29.87% at 35 months. No adverse effects were noted. Patient satisfaction was high at the end of the evaluation. Retreated patients were more satisfied than non-retreated ones. However, there was no difference in the anisotropy factor between the two groups. CONCLUSION: Treatment of facial rhytids with a non-ablative 1540-nm Er:glass laser system can produce benefits that persist over 2 years after the last treatment.

Adult↗
PubMed2004

Nd:YAG laser combined with IPL treatment improves clinical results in non-ablative photorejuvenation.

BACKGROUND: Intense pulsed light (IPL) sources have been reported in non-ablative photorejuvenation, but the excellent histological findings do not always coincide with the clinical results and patient satisfaction index (SI). METHODS: Ten female patients (two forehead, four periocular and four perioral), ages ranging from 28 to 46 years, skin types II-IV, wrinkle types I-III, participated in the study. The IPL system was applied with the yellow (570 nm) cut-off filter, 30 J/cm(2), single pulse, followed by the Nd:YAG at 120 J/cm(2), double pulse (7 ms per shot with 20 ms between pulses) on the wrinkled areas only. Three sessions were given at monthly intervals, and an assessment was made 1 and 6 months after the third session. Biopsies were taken from four consenting patients as a cross-section before the first treatment and then 1 and 6 months after the third session. For clinical control and contrast of tissue results, a group of 10 patients (two forehead, four periocular and four perioral; ages ranging from 27 to 47 years, skin types II-IV, wrinkle types I-III) was treated only with IPL, using the same parameters and sessions. Histologies were taken from four consenting patients. RESULTS: The histology showed thickening of the epidermis with good dermal collagen organization in both groups. However, the combined treatment showed more dramatic changes in histological tissue condition, and ectatic blood vessels were seen in the deeper dermis. The patient SI values, related to the results, were lower when IPL was used alone. All patients completed the study. In the combined treatment group, overall SIs of 8 (80%) and 8 (80%) were obtained at the control points of 1 and 6 months, respectively, after session 3, compared with SIs of 6 (60%) and 4 (40%) scored by patients in the IPL group at the same points. Discomfort and side effects were minimal in both groups. CONCLUSIONS: The addition of the Nd:YAG laser to the IPL regimen in non-ablative skin rejuvenation gave very good histological results, which were echoed by stronger patient satisfaction than in the control group treated only with IPL. Visible improvement in the skin condition of both groups was achieved, but was better in the combined treatment group.

Adult↗
PubMed2004

Calpain inhibitors improve myocardial dysfunction and inflammation induced by endotoxin in rats.

Excessive activation of calpains has been implicated in the pathophysiology of inflammation, trauma, and ischemia reperfusion injury. Here, we investigated the effects of calpain inhibition on myocardial dysfunction and inflammation induced by endotoxin in rats. Rats were treated i.v. with endotoxin (10 mg/kg) or endotoxin plus calpain inhibitors and were then prepared after 4 h for myocardial contractility assessment, detection of endothelium leukocyte interactions, and plasma TNF-alpha, nitrite/nitrate, and endocan levels. Compared with vehicle-treated rats, hearts from endotoxin-treated rats had reduced systolic performance that was partially prevented by calpain inhibitors, i.e., acetyl-leucyl-leucyl-arginal (leupeptin), carbobenzoxy-valyl-phenylalanial (calpain inhibitor III), and N-acetyl-leucinyl-leucinyl-norleucinal (ALLN). Leupeptin and calpain inhibitor III reduced plasma TNF-alpha levels in endotoxin-treated rats. ALLN reduced plasma TNF-alpha and nitrite/nitrate levels in endotoxin-treated rats. Endotoxin treatment increased mesenteric venule leukocyte rolling (10 +/- 3 leukocytes/min vs. 44 +/- 10 leukocytes/min; P < 0.01) and adhesion (2 +/- 2 leukocytes/min vs. 15 +/- 3 leukocytes/min; P < 0.01), which was reduced by calpain inhibitors. Attenuation of leukocyte endothelium interactions observed in calpain inhibitor-treated rats with sepsis was associated with increases in plasma anti-adhesion molecule endocan. In conclusion, calpain inhibitors improved endotoxin-induced cardiac dysfunction, which may be attributed to the modulation of endothelium leukocyte interactions in the inflamed vasculature.

Animals↗
PubMed2004

Endotoxin-induced myocardial dysfunction: evidence for a role of sphingosine production.

OBJECTIVE: To determine whether sphingomyelinase pathway activation would participate in myocardial depression induced by endotoxin. DESIGN: Randomized, controlled trial. SETTING: Experimental laboratory. SUBJECTS: Male Sprague-Dawley rats, isolated rat heart, and cardiac myocytes. INTERVENTIONS: Cardiovascular function was evaluated in rats injected with saline, endotoxin (10 mg/kg, intravenously), and N-oleoylethanolamine (NOE; 10 mg/kg, intravenously). In ex vivo experiments, isolated rat hearts were perfused with endotoxin (5 microg/mL). For pharmacologic intervention, NOE (1 micromol/L) was admixed to the perfusate 20 mins before endotoxin. In in vitro experiments, ventricular myocytes were incubated with sphingosine (20 microM). Myocyte cell shortening and calcium transient were measured. Mitochondrial membrane potential was measured using the cationic dye tetramethylrhodamine methylester fluorescence technique. MEASUREMENTS AND MAIN RESULTS: Endotoxin treatment at 4 hrs did not alter mean arterial pressure and abdominal blood flow compared with control rats. Left ventricle developed pressure (LVDP) and its first derivatives (i.e., maximal and minimal change in pressure over time [dP/dtmax and dP/dtmin]) were decreased after 4 hrs in endotoxin-treated rats compared with control rats. NOE (10 mg/kg) treatment largely prevented left ventricular systolic function alterations of endotoxin-treated hearts (n = 6 in each group). In isolated rat heart, endotoxin (5 microg/mL) caused increases in tumor necrosis factor-alpha perfusate concentration and delayed depression of LVDP, dP/dtmax, and dP/dtmin after 60 mins, which was partially abrogated in the presence of the ceramidase inhibitor NOE (1 micromol/L). Sphingosine (20 microM) caused decreases in cell fractional shortening, calcium transient, and mitochondrial membrane potential of cardiac myocytes. CONCLUSION: These observations suggest that the sphingomyelinase pathway participates in endotoxin-induced myocardial depression.

Animals↗