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Biomedical subjects

S Mordon

Publications and source records attributed to S Mordon.

At least 19 recordsLinked to original sources
PubMed2005

Photodynamic therapy for early oesophageal cancer.

BACKGROUND: Photodynamic therapy is an endoscopic treatment of early cancers based on the photosensitisation of neoplasms following the administration of a photosensitiser prior to laser light-induced tissue destruction. AIM: To assess the results of photodynamic therapy using Photofrin(Axcan Pharma Inc., Quebec, Canada) in patients with an early oesophageal cancer. PATIENTS: Twenty-four patients with early oesophageal cancer presenting as a not well-demarcated irregular dyschromic area of mucosa and unsuitable for any other treatment underwent photodynamic therapy. RESULTS.: Seventy-five per cent were successfully treated; three of them recurred and two died from head and neck cancer. To date, 54% of patients are alive without recurrence; the average follow-up is 21 months. There were one oesophageal lethal perforation and six stenosis. Results of photodynamic therapy were limited in this series by three failures, three recurrences and three deaths from previous head and neck cancers. CONCLUSION: This study provides some promising data for photodynamic therapy of oesophageal carcinomas in selected patients. It also emphasises the need for a best delivery device of laser light.

Aged↗
PubMed2004

Long pulse Nd:YAG laser for treatment of leg veins in 40 patients with assessments at 6 and 12 months.

BACKGROUND AND OBJECTIVES: This study assessed subjectively and objectively the efficacy of a long-pulsed Nd:YAG laser system in clearing dermal leg veins, successful treatment of which remains problematic. STUDY DESIGN/PATIENTS AND METHODS: Forty female patients (24-58 years old, skin types II-IV) with leg veins were treated with synchronized micropulses from a long-pulsed 1,064 nm Nd:YAG laser, 6 mm diameter spot size, 130 and 140 J/cm2. One to three treatments were given at 6-week intervals, with post-treatment assessments at 6 and 12 months. Patients assessed improvement subjectively with a satisfaction index (SI). Objective assessment was based on the clinical photography, and in addition on computer-generated data from a Canny operator-based edge-detection program. RESULTS: The overall patient satisfaction rates and objective assessments at the 6 and 12 month assessments were 42.5 and 57.5%, and 75 and 82.5%, respectively. CONCLUSIONS: The long-pulsed Nd:YAG laser offered efficient treatment of leg veins. Side effects were minimal and transient. The edge-detection program may help patients appreciate better the actual results of the treatment.

Adult↗
PubMed2004

[Cartilage reshaping by laser in stomatology and maxillofacial surgery].

The restoration of congenital and traumatic malformations of the head and neck, together with the defects resulting from the trauma of ablative surgery, continue to pose significant problems to surgeons. The post-operative results are not always satisfactory because of the difficulty of shaping the cartilage and because of the tendency of cartilage to return to its original shape. Better understanding of laser-cartilage interaction and the development of a specific instrumentation Lasers (CO2, Nd: YAG, Ho: YAG) has enabled ex situ and in situ cartilage reshaping. A recent clinical study has demonstrated that nondestructive laser irradiation can reshape septal deviations

Adolescent↗
PubMed2004

[Photodynamic therapy follow-up: when to retreat, when to observe, or when to propose an alternative treatment?].

Clinical and angiographic progression after photodynamic therapy (PDT) is usually slow, sometimes fluctuating and therefore difficult to evaluate. After several sessions of PDT, angiographic follow-up remains the basis for therapeutic management involving either a new PDT session or an alternative treatment. It remains difficult, however, to evaluate the activity and progression potential of the remaining neovessels. Imaging (angiography, optical coherence tomography) and functional data both contribute to the therapeutic decision. Certain patients require several sessions for a progressive reduction of the exudation. For others, the persistence of metamorphopsias and accentuation of the scotoma despite the treatment may entail alternative treatment. Thus, a perifoveal photocoagulation can be proposed to limit the extension of the scotoma if after a reasonable number of sessions, central visual acuity is not recovered; direct photocoagulation of a persistent active neovascular contingent, distant from the fixation zone (foveal or exenterated) can be proposed if it remains on the border of a stabilized lesion; the treatment of a feeder vessel can be proposed if it becomes visible and is associated with active neovessels with a persistent central serous detachment of the neuroretina. Lastly, performance status and patient wishes are important elements in the overall therapeutic project, especially if the eye involved is the second eye, in view of quickly initiating low-vision rehabilitation.

Fluorescein Angiography↗
PubMed2004

[Fluorescence imaging technique: diagnostic and therapeutic interest in gynecology].

Fluorescence techniques are presently used by several medical and surgical disciplines (dermatology, pneumology, urology, gastrointestinal surgery) for the diagnosis of pre-cancerous and cancerous lesions. The technique is based on the application of 5-aminolevulinic acid (5-ALA) which induces the production of an endogen photosensitizer: protoporphyrin IX (PpIX). Fluorescence detection of the infraclinical dysplasia lesion is based on the contrast between fluorescent pathological tissue and non-fluorescent healthy tissue. Moreover, there is a correlation between the degree of tissue dysplasia and fluorescence intensity. Fluorescence imaging could allow easier detection of infraclinical lesions enabling more well-targeted treatment. In gynecology, many experimental and clinical studies have been conducted on the detection and treatment of cervical dysplasia and the diagnosis and treatment of vaginal and vulvar diseases as well as the diagnosis of peritoneal micrometastasis from ovarian cancer, the diagnosis and treatment of endometrial alterations, and the treatment of locoregional recurrent skin breast cancer. The aim of this work is to present the fundamental principles of fluorescence imaging technical and to expose the diagnostic and therapeutic prospects in gynecology.

Aminolevulinic Acid↗
PubMed2004

[Transpupillary thermotherapy and age-related macular degeneration].

Transpupillary thermotherapy (TTT) has been proposed over the last a few years for the treatment of subfoveal occult choroidal neovessels resulting from age-related degeneration (AMD) when they are symptomatic and associated with exudation. Several pilot studies have shown how this technique can decrease or slow down the progression of exudation related to choroidal neovessels. Based on these pilot studies, a randomized study (TTT4CNV) is in progress to evaluate the efficacy of TTT. While the inclusion of the patients in this study has come to an end, the therapeutic context of AMD has recently been changed with a permit to market Visudyn for photodynamic therapy (PDT) for some types of subfoveal occult choroidal neovessels. Moreover, the clinical studies in progress on photodynamic therapy and antiangiogenic drugs now make it possible to consider combined treatments possibly including TTT. This paper aims to provide a report on the current place and potential of TTT within the therapeutics available or soon available for subfoveal occult choroidal neovessels of AMD.

Angiogenesis Inhibitors↗
PubMed2002

Treatment of leg telangiectases with a 532 nm KTP laser in multipulse mode.

BACKGROUND: The multiple mode emission emphasizes the efficacy of the KTP laser. OBJECTIVE: To evaluate the efficacy of a 532 nm KTP laser emitting in multipulse mode for the treatment of superficial 0.5-1 mm leg telangiectases. METHODS: A 532 nm KTP laser was used in a nonuniform pulse sequence or multipulse mode emission (three stacked pulses of 100 msec, 30 msec, 30 msec, and a delay between pulses of 250 msec), a fluence of 60 J/cm2, and a 0.75 mm collimated spot. No cooling was used. Fourteen female patients (average age 46 years, range 27-57 years), phototypes I-IV were examined with Doppler ultrasound to ensure their big veins were competent. A topography of the telangiectatic network was reported on a tracing plastic frame before each session and 6 weeks after the last one. These frames were digitized and the number of vessels (before and 6 weeks after each session) was determined using imaging software. Side effects, pain, and patient satisfaction were noted. RESULTS: Moderate pain, immediate erythema and edema, sometimes light scabbing, temporary hypopigmentation rarely, and no matting were observed. After one treatment, vessel clearing was 53% (P <.001). It increased to 78% (P <.001) 6 weeks after two treatments, to 85% (P <.05) 6 weeks after three treatments, and to 93% (NS) 6 weeks after four treatments. CONCLUSION: This nonuniform pulse sequence or multipulse mode emission emphasizes the efficacy of the KTP laser in this study. It provides a safe and effective treatment that achieved an important reduction of red leg veins telangiectases from 0.5 to 1 mm in diameter, with very few side effects.

Adult↗
PubMed2001

Laser assisted skin closure (LASC) by using a 815-nm diode-laser system accelerates and improves wound healing.

BACKGROUND AND OBJECTIVE: This study aimed to evaluate a 815-nm diode-laser system to assist wound closure to accelerate and improve healing process. STUDY DESIGN/MATERIALS AND METHODS: A total of 25 male hairless rats (mutant OFA Sprague-Dawley rats, IFFA-CREDO, L'Arbresle, France) with four dorsal skin incisions were used for the study. For each wound, the good apposition of the edges was obtained with buried absorbable suture. In the laser group, the laser beam was applied spot by spot through a transparent adhesive dressing along two incisions with the following parameters: 1.5 W; 3 seconds; spot diameter, 2 mm; fluence, 145 J/cm(2). Both control wounds were closed with conventional suture techniques. The duration of the closure procedure was noted for each group. Clinical examination, histologic study, and measurement of tensile strength were performed at 3, 7, 15, and 21 days after surgery. Determination of activation of heat shock protein 70 (Hsp70) through immunocytochemistry was performed at days 1 and 7. RESULTS: LASC was 4 times faster to process than conventional suture: 1 minute 49 +/- 20.6 seconds vs. 7 minutes 26 +/- 62.2 seconds. In the laser group, healing was accelerated resulting in a more indiscernible scar than in the control groups. Histologic aspect was better with earlier continuous epidermis and dermis and a thinner resulting scar. Tensile strength was 30 to 58% greater than in control groups at 7 and 15 days (P < 0.001). Expression of Hsp70 was markedly induced in skin structures examined after laser exposure. CONCLUSIONS: This study shows the ability of the 815-nm diode-laser system to assist wound closure leading to an acceleration and an improvement of wound healing with indiscernible resulting scar. The mechanisms of this phenomenon are still unclear but further investigations are in progress to attempt to explain them.

Animals↗
PubMed2001

Treatment with 815-nm diode laser induces long-lasting expression of 72-kDa heat shock protein in normal rat skin.

BACKGROUND: We previously reported that skin closure is improved by photoirradiation of the wound margins with an 815-nm diode laser system. OBJECTIVES: To determine whether the beneficial effects of laser treatment involve the overexpression of the inducible 72-kDa heat shock protein, Hsp70. METHODS: Expression of Hsp70 was investigated by immunocytochemistry in normal hairless rat dorsal skin and compared with its expression after laser photoirradiation. RESULTS: Constitutive expression of Hsp70 was mainly confined to the upper epidermal layer. Laser irradiation further increased epidermal expression of Hsp70 while inducing de novo synthesis of the protein in dermal structures, particularly around blood vessels, hair follicles and sebaceous glands. Laser-induced expression of Hsp70 was still present 7 days after photoirradiation. CONCLUSIONS: Laser-induced expression of Hsp70 might contribute to improved tissue regeneration and wound healing.

Animals↗
PubMed2001

Nonablative remodeling: clinical, histologic, ultrasound imaging, and profilometric evaluation of a 1540 nm Er:glass laser.

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.

Adult↗
PubMed2001

Er:YAG laser resurfacing using combined ablation and coagulation modes.

BACKGROUND: The two main laser types used in resurfacing, the CO2 and the Er:YAG lasers, have their supporters and detractors, and each system has clear advantages and disadvantages. OBJECTIVE: The Er:YAG laser can be used in the usual efficient ablative mode, followed by reprogramming to achieve nonablative deeper dermal coagulation associated with the CO2 laser, thereby achieving the main advantages of both laser types. PATIENTS AND METHODS: Twenty-three female patients, ages 42-72 yrs, skin types I-IV, were treated. The epidermis was first removed in the ablative settings in a single pass with 50% overlap. The Er:YAG laser was reprogrammed for the subablative mode, and several passes produced controlled residual thermal damage (RTD) without further ablation. RESULTS: At 2 months postresurfacing the results were assessed. Thirteen patients were rated "very good," eight as "good," and two as "fair." CONCLUSION: The dual mode Er:YAG laser can first be used in the ablative mode to remove the epidermis with minimal RTD, following which, in the subablative mode, the same laser induces a controlled layer of dermal RTD, stimulating the dermis to achieve collagenesis and collagen remodeling and giving good long-term results.

Adult↗
PubMed2001

Treatment of wrinkles with the nonablative 1,320-nm Nd:YAG laser.

Ablative laser resurfacing with the CO2 and Er:YAG lasers has become a well-accepted and well-reported modality for skin rejuvenation of photoaged and photodamaged skin. However, the side effects associated with these lasers, such as exudation and crusting followed by prolonged erythema, are often socially disturbing for the patient. A nonablative 1,320-nm pulsed Nd:YAG system has been developed that controls dermal collagen damage while preserving the epidermis. Thirteen patients are presented on whom periocular wrinkle treatment was carried out during two sessions 1 month apart. Side effects were minimal. Histology showed improvement in the previously typical sun-damaged dermis. However, although physician assessment noted a trend toward macroscopic improvement, almost all patients failed to see any improvement. The authors conclude that further studies of the ideal parameters are required before the 1,320-nm Nd:YAG laser can be indicated successfully in stand-alone, nonablative wrinkle removal. In addition, patients should be selected carefully, and a complementary minimally aggressive technique should be used to restore a youthful appearance to the epidermis.

Adult↗
PubMed2001

Antithrombin reduces mesenteric venular leukocyte interactions and small intestine injury in endotoxemic rats.

We examined the hypothesis that recombinant human antithrombin would reduce mesenteric venule leukocyte adhesion and small intestine injury in endotoxemic rats. Endotoxemic (endotoxin 10 mg/kg, intravenously) rats were treated either with saline or recombinant human antithrombin (250 and 500 U/kg). In some rats, indomethacin (100 mg/kg, intraperitoneally) was injected 60 min prior to endotoxin and recominant human antithrombin (500 U/kg) treatment. Compared to controls, intravital videomicroscopy of the mesentric venule showed an increase of leukocyte rolling (55+/-17 versus 70+/-19 leukocytes/min; P < 0.05) and firm adhesion (1.1+/-0.3 versus 5.8+/-0.8 leukocytes/100 microm; P < 0.05) in endotoxemic rats. Recombinant human antithrombin attenuated endotoxin-induced venular endothelium leukocyte adhesive cascade. The beneficial effects of recombinant human antithrombin on leukocyte adhesion were inhibited by indomethacin (100 mg/kg, intraperitoneally) in endotoxemic rats. Endotoxin treatment increased fluorescein isothiocyanate (FITC)-labeled dextran 4,000 (FD4) gut lumen to plasma ratio and wet weight/dry weight ratio. Recombinant human antithrombin (500 U/kg) attenuated endotoxin-induced gut injury. These observations suggest that recombinant human antithrombin reduces endothelium-leukocyte interactions in endotoxemic rats by interacting with local prostacyclin production.

Animals↗
PubMed2001

Heat shock protein hyperexpression on chorioretinal layers after transpupillary thermotherapy.

PURPOSE: To assess a biological effect induced by temperature elevation during transpupillary thermotherapy (TTT). METHODS: Six pigmented rabbits were anesthetized, and TTT was performed on the right eye using an 810-nm diode laser installed on a slit lamp (spot size, 1.3 mm; duration, 60 seconds; power, 92-150 mW). A series of laser pulses were aimed at the posterior pole of the retina. The left eyes were used as the control. Twenty-four hours after laser irradiation, a histologic study was performed on the chorioretinal layers. Tissue samples were fixed in formalin and embedded in paraffin. A monoclonal antibody was used to detect heat shock protein (Hsp)70 immunoreactivity, followed by a biotinylated goat anti-mouse antibody, revealed by the avidin-biotin complex and the 3-amino-9-ethyl-carbazole (AEC) chromogen. Retinal structures were further identified by hematoxylin erythrosin saffron (HES) coloration. RESULTS: The photocoagulation threshold was found to be at the 150-mW laser power. Under this threshold, Hsp70 immunostaining was the strongest at the 127-mW power, with staining of some choroidal cells, including capillary endothelial cells. No Hsp70 immunoreactivity was observed on the retina. At the 107-mW power, Hsp70 reactivity was observed only in occasional choroidal cells. At the 98-mW power, only mild, diffuse Hsp70 immunoreactivity was observed in the choroid. At the 92-mW power, as in nonirradiated eyes, no Hsp70 immunoreactivity was detected. CONCLUSIONS: Subthreshold transpupillary 810-nm laser irradiation induces choroidal Hsp hyperexpression. This confirms that choroidal Hsp hyperexpression can be induced during TTT, as has been recently hypothesized by several investigators.

Animals↗
PubMed2001

[Choroidal heat shock overexpression in transpupillary thermotherapy: preliminary results].

PURPOSE: To assess retinochoroidal overexpression of heat shock proteins (HSP-70) induced by a transpupillary laser irradiation below the photocoagulation threshold. METHODS: Four pigmented rabbits were anesthetized and TTT was performed on the right eye using a 810nm diode laser (Iridis, Quantel-Medical, France) adapted on slit lamp (spot size: 1.3 mm, duration: 60 seconds; power 92-150 mW). Series of laser impacts were aimed at the posterior pole of the retina. Left eyes were used as control. Twenty-four hours after laser irradiation, a histological study was done on chorioretinal layers. Tissue samples were fixed in formalin and embedded in paraffin. A monoclonal antibody was used to detect HSP-70 immunoreactivity (mouse IgGl, SPA-810, Stress Gen, Canada), followed by a biotinylated goat antimouse antibody (Dako, Denmark), revealed by the avidin-biotin complex (Vectastain kit, Vector, USA) and the AEC chromogen. Retinal structures were further identified by HES coloration. RESULTS: The photocoagulation threshold was obtained for laser power at 150 mW. Under this threshold, HSP-70 immunostaining was the strongest for power 127 mW with a staining of some choroidal cells, including capillary endothelial cells. No HSP-70 immunoreactivity was observed on the retina. For the laser power 107 mW, HSP-70 reactivity was observed only in occasional choroidal cells. For the laser power 92 mW, as for nonirradiated eyes, no HSP-70 immunoreactivity was detected. CONCLUSIONS: Transpupillary 810 nm laser irradiation under the photocoagulation threshold induces choroidal HSP overexpression. This study concludes that choroidal HSP overexpression can be induced during TTT.

Animals↗