Laser is an acronym for a physical principle and means: Light Amplification by stimulated Emission of Radiation. This principle offers a lot of tissue/light effects caused by the parameters: power density/time and the special qualities of the laser light. Nowadays for diagnosis and therapy following lasers are used in urology: Krypton- and Dye-lasers as well as the Neodymium-YAG- (nd:YAG-), Holmium-YAG (Ho:YAG-), Diode-, Argon- and the CO₂-lasers.

Introduction. A considerable confusion exists in literature regarding the comparison between the employ of the laser and TUR for the treatment of Superficial Bladder Cancer (SBC) in terms of tumour recurrences (number, progression of stage and grade, place and time of them) and the economic costs. For this reason we have analysed the two procedures by a retrospective study to evaluate if the laser treatment had same advantages on the TUR which is still now considered the gold standard treatment. Materials and Methods. We examined two groups of 50 elderly patients with DBC, high incidence of comorbilities and anaesthesiological risk, who were treated by TUR or Ho. Yag laser. We considered for teh resected tumours: stage, grade, size, multiplicity, history. Of the recurrences were analysed: number, place, time of appearance, grade and stage. Besides the time of surgical procedure, the complication rate, the catheterization time and the hospital stay were evaluated. Results. There was not a clear difference between laser and TUR about the recurrences for: number (30% and 36%), progressoin of stage and grade, place and time of appearance. An important results it was that at parity of surgical time in the laser group we had: 50% less of complications, 75% of the patients removed the catheter within 24hs with a postoperative stay of 24-48 hs instead of 4% and 40% in the TUR group. Conclusions. We conclude that the use of the Ho: YAG laser is actually the most advantageous method to treat the elderly with comorbilities and affect by little relapsing and low grade SBC for the low complication rate, reduction of the catheritization time, the hospital stay and the economic costs. These results point out that the Ho:Yag laser is an interesting technology to treat the elderly with comorbilities and this characteristic is still more important if we consider that for the ageing of the population we are moving towards an increase of the elderly urological pathology.

Introduction of the photosensitizer properties of cytostatics drus was made, pointing out that the fact that besides the biochemical action of the cytostatics their effects could be enhanced by the exposure to light at different doses. A spectroscopical characterisation of methotrexate and fluorouracil, cytostatic drugs used frequently in cancer therpy was performed. The absorption, emission and excitation spectra were measured for methotrexate solutions in natural saline and sodium hydroxide at concentration in the range 10^-5 -10^-6M and pH 8.4. The absorption, emission and excitation spectra were measured for fluorouracil solutions in natural saline at concentration in the range 10^-4 -10^-5M. The absorption spectrum exhibits spectral bands in the range 250nm -450nm for both drugs. The fluorescence excitatioan for methotrexate was made at 340nm and 370nm, the fluorescence emission was detected in the spectral range 400nm - 500nm with a maximum at 470nm. The fluorescence excitation was measured in teh range 200nm-500nm with the emission centred on 530nm, for Xe lamp irradiation, and 300nm for Hg lamp and laser irradiation. The fluorescence emission spectra was monitored in the spectral range 400nm - 600nm. The effects of irradiation on spectroscopic characteristics of methrotrexate and fluorouracil were investigated. The irraditaion was made using a UV classic lamp with Xe, for the first experimental part and for the second one it was used both a class Hg lamp and a nytorgen pulsed laser.

Background and Objective: The detailed multivariate analysis of endometrial tissue fluorescence spectra was done. Spectra underlying features and classification algorithm were analyzed. An effort has been made to determine the importance of neopterin component in endometrial premalignization. Study Design/Materials and Methods: Biomedical tissue fluorescence was measured by excitation with the Nd YAG laser third harmonic. Multivariate analysis techniques were used to analyze fluorescence spectra. Biomedical optics group at Vilnius University analyzed the neopterin substance supplied by the Institute of Medical Chemistry and Biochemistry of Innsbruck University. Results: Seven statistically significant spectral compounds were found. The classification algorithm classifying samples to histopathological categories was developed and resulted in sensitivity of 80% and specificity 93% for malignant vs. hyperplastic and normal. Conclusions: Fluorescence spectra could be classified with high accuracy. Spectral variation underlying features can be extracted. Neopterin component might play an important role in endometrial hyperplasia development.

This study determined, in vitro, the coronal leakage of root canals evaluating the effect of smear layer removal by either EDTA or laser. Two sealers were also compared. Sixty-four canines were instrumented with the step-back technique and irrigated with 10 ml of 1% sodium hypochlorite. In Group 1, 10 teeth were sealed with Sealer 26 and 10 teeth were sealed with Grossman cement with no attempt of smear layer removal. Group 2 received a final irrigation of 15 ml of 17% EDTA, and was sealed as in Group 1. Group 3 received Er:YAG laser application (140 mJ, 15 Hz and 42 J), and sealed as in Group 1. Root canals sealed with Sealer 26 had significantly less coronal leakage than Grossman cement (P<0.05). Coronal leakage afte smear layer removal with 17% EDTA or Er:YAG laser was not statistically different (p>0.01).

A summary of using near (Nd) and middle (Er) infrared YAG laser systems in ophthalmology surgery is given in the paper. The report on twelve years of clinical experience with the ophthalmic Nd:YAG laser system (λ=1.06 μm) operating alternatively on Q-switched or mode-locked regimes is accomplished. From statistical data processing of more than 1000 interventions it follows that better results in a posterior capsule opacification cure are achieved with the use of short, near-infrared mode-locked 25 ps long pulses, while 4 ns long giant pulses of the same wavelength are useful for iridectomy creations. Middle infrared radiation generated by the Er:YAG laser system (λ-2.94 μm) was used for pre-clinical interaction experiments (in vitro). Differences in results of cornea, lens and sclera ablation by a free running (110 μs long) and Q-switched (250 ns long) mid-infrared pulses are presented. The radiation was delivered to the interaction place either by a system of reflected mirrors (used for Nd:YAG laser), or by a special sealed waveguide (in the case of Er:YAG system).

Introduction: The classic indication for photodynamic therapy (PDT) in ophthalmology is currently represented by classic subfoveal choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD). PDT is a method, which almost selectively causes endothelial damage in neovascular lesions, followed by vascular occlusion and involution of the CNV. The mechanistic aspect suggests that non AMD-related choroidal neovascularisations might also benefit from PDT. PDT in AMD: Within the German health system, PDT indications follow the criteria based on the inclusion criteria of the TAP studies. For instance the CNV should be predominantly classic and located under the center of the foveal avascular zone. In the diagnosis and follow-up of exudative AMD, visual acuity measurements and fluorescein angiography are the established parameters. Retinal thickness analyzer (RTA) measurements might give further information. Before PDT, they show a significant retinal thickening due to intra- and subretinal exudation. Following PDT, early RTA follow-ups show a clear decrease in retinal thickening accompanies by increasing or stable acuity. PDT in CNV of other origins than AMD: New studies support a new spectrum of indications for PDT, hopefully leading to general cost reimbursement for patients. PDT should be viewed as a general method for vascular occlusion and does not represent a causal therapy for progressive exudative AMD. We present patients with CNV due to pathologic myopia, angioid streaks and POHS. Conclusion: The selective vascular occlusion caused by PDT, besides CNV associated with AMD and pathologic myopia, may also allow the treatment of choroidal neovascularisations based on other entities. Careful individual evaluation of those cases is recommended. Despite this wide array of possible indications, cost reimbursement has been limited to classic subfoveal CNV in AMD, although single case reimbursements in choroidal neovascular lesions due to pathologic myopia have been observed.

No abstract available.

No abstract available.

Leg telangiectasias are venous, arterial and arteriovenous capillarya dilatations of the subpapillary dermal plexus, which is directly connected to the deep dermal plexus and indirectly through perforating to the subfascial saphenic and deep venous circulation. These angectasias are almost always indicators of varicose pathology. After accurage history taking and precise diagnosis they should be treated by sclerosis, but only after having verified possible saphenous ostial refluxes which must be eliminated first by surgical means. Laser photosclerosis is aimed at the small (red) residual, resistant and matting vessels. The 532nm lasers are irreplaceable because of the surface delicacy with which they vaporise selectively the telangiectatic and vascular malforming lesions of the face. The aim of this study was to verify the effectiveness of the 532nm on leg angectasiae resistant to sclerotherapy. We used a laser 532nm Combi Zeiss, Jena in 20 cases selected for residual, resistant relapsing and matting leg telangiectasias (0,1 -1mm) on a total of 64 angectatic areas. The areas were cooled down with ice cubes for at least two minutes. 15 - 40 J/sq cm fluences, 10 - 50 msec. pulse durations and 1,5 mm spots were applied. As soon as the vessel blanched, it was cooled down for two further minutes. Four patients had positive results after one session only, twelve patients asked for a second session after 20 days, four patients were retouched for a third time. Follow up examinations were performed after 7-30 days and one year. In all cases the treatment was reported as painless. The immediate erythema was followed by microcrusting in 52 areas, which disappeared in 15-20 days. The one-year follow-up evidenced partial relapses in six patients and complete replases in four on a total of 30 areas (48%). Two patients had hypo-chromic micro-scars in three areas; two patients had four residual dyspigmented areas. Our results suggest that the use of the 532nm laser is justified in the treatment of residual, resistant, relapsing and matting after sclerotherapy telangiectases.

CO₂ lasers has been used for five years at Malaren Equine Hospital, as an alternative treatment of some equine diseases. The application of CO₂ laser has been studied for evaluation of its appropriateness for treatment of the equine diseases sarcoids, lameness in fetlock joints or pulmonary haemorrhage. During the last five years, above 100 equine sarcoids have been removed by laser surgery (CO₂ laser) and so far resulting in significantly few recurrences compared with results from usual excision surgery. In one study, acute traumatic arthritis in fetlock joints was treated three times every second day with defocalised CO₂ laser. The therapeutic effectiveness of CO₂ laser in this study was better than that of the customary therapy with betamethasone plus hyaluronan. During one year, chronic pulmonary bleeders, namely exercise induced pulmonary haemorrhage, has been treated with defocalised CO₂ laser. Six race horses have been treated once daily during five days. Until now, three of these horses have subsequently been successfully racing and no symptoms of pulmonary haemorrhage have been observed. These studies indicate that CO₂ laser might be an appropriate therapy on sarcoids and traumatic arthritis, and probably also on exercise induced pulmonary haemorrhage. Other treatments for this pulmonary disease are few.

The Low Level Laser Therapy (LLLT) has been widely tested in arthritis disorders, but there is still some disagreement in the results, therefore in this study we have investigated High Intensity Laser Therapy (HILT). The degenerative arthritis was induced in 18 chickens by intra-articular inoculation of Freund's complete adjuvant. Clinical studies were carried out (weight increase and grades of lameness) as well as morphological (macroscopic and histological) tests and seroassay (C Reactive Protein). The Nd:YAG pulsed wave was employed. The serologic data revealed the anti-inflammatory effect on the laser, with a highly significant difference between those treated and the control group. No lesion on the skin, i.e. burn, or in depth has been observed in the Treated group. Heavyline of broiler chickens in growing age has been revealed a good animal model of O.A.. The Nd:YAG Pulsed Wave it is safe on these structures. The anti-inflammatory effect of the HILT it seems to contrast the destructive degenerative process.

The aims of this study was the safety and the efficacy of High Intensity Laser Therapy (HILT) on chronic degenerative tenosynovitis. We have effectuated the histological evaluation and seroassay (C reactive protein) on 18 chickens affect by chronic degenerative tenosynovitis experimentally induced. We have been employed a Nd:YAG laser pulsed wave; all irradiated subjects received the same total energy (270 Joule) with a fluence of 7,7 J/cm² and intensity of 10,7 W/cm². The histological findings revealed a distinct reduction of the mineralization of the choral matrix, the anti-inflammatory effect of the laser, the hyperplasia of the synoviocytes and ectasia of the lymphatic vessels.

We have treated with CO₂ laser surgery 40 cases which contemplated: stomatitis and other oral pathologies, anorectal, cutaneous, subcutaneous lesions, and other ophthalmic ones. The parameters employed to evaluate surgical treatment success were: histological analyses, time of healing process and incidence (per cent) of relapses. During the T/3 period (45 days) all cases of feline stomatitis relapsed. The 83% of pets that suffered of anorectal pathologies healed up to 21 days and no relapse was observed in T/4 period (180 days). The cutaneous and subcutaneous nodules vaporization caused lesions that healed during 7 days (T/1) and no relapse was observed after laser treatment. In cutaneous chronic ulcers and in reptilian abscesses we had the lesions reparation by second intention healing in T/3. A case of feline oral squamocellular carcinoma relapsed in T/3 after laser treatment. The results showed three different level of utility: indispensable, useful but unnecessary, inefficacious. The CO₂ laser application resulted the best treatment for anorectal pathologies, cutaneous ulcerations and reptilian abscesses. The laser surgery was only useful but unnecessary in treatment of cutaneous and subcutaneous neoformations and also in oral and peri-ophthalmic pathologies. Finally, the laser application appeared inefficacious in squamocellular carcinoma and in chronic phlogosis of feline oral cavity.

The ultrasonic evolution of tendinous repair envisages the recovery of ecogenicity: "reparative phase", followed by the realignment of the collagen fibres: "rehabilitative phase". The primary objective was to verify the safety and efficacy of Nd:YAG pulsed wave on teno- desmopathies of horses. Secondary to shorten "reparative phase" for to provide more time for "rehabilitative phase". The study has been divided into two investigations: experimental and clinical. In the experimental investigation, on 3 meat horses, the safety and tolerance of a power laser (35 W/cm₂, 25 J/cm²) was investigated. The clinical investigation was performed on 79 sport horses through randomized double-blind. All subjects (Controls and Treated) received, on the subskin above the tendon lesion, the same local infiltration of immunostimulant. The results indicates that the High Intensity Laser Therapy (HILT) is safe and tolerated. It is able of reducing, in significative way, the "reparative phase", with a lower percentage of relapse (20% Treated and 40% Controls), but it is not able to reduce the time of the "rehabilitative phase".

In the marginal pr ogressive profound periodontities, we associated low level laser therapy (LLLT) to the classical surgical treatment with implant of biovitroceramics. From a total of 50 patients, 37 where irradiated with the laser. We used a diode laser, =830 nm, energy density up to 2 J cm², in Nogier pulsed mode. The laser treatment is used in a complex of therapeutic procedures: odontal, local anti-inflammatory -- as well as in the cabinet and at home --, prosthetic, and for the morphologic and functional rebalancing. The immediate effects where: an evolution without bleeding and without post-surgical complications, as can appear at the patients who didn't benefit of laser irradiation (hematom, pain, functional alteration in the first post-surgical week). Operated tissue is recovering faster. The percentage of recurrences decreases and the success depends less on the biological potential and the immunity of each individual.

There are no doubts about benefits of non-invasive laser therapy in treating surgical wounds thanks to its anti-inflammatory, stimulating and analgesic effects. Systemic enzymotherapy is particularly employed due to its thrombolytic, fibrinolytic and antiedema effects. Concurrent use of the two above mentioned treatment modalities exerts synergistic action. Thus, it is possible to reduce the persistence of the pain as well as duration of the post-operation period after surgical interventions in the mouth cavity at a statistically highly significant level. Thus, this approach can be recommended for achieving a favourable course in most post-operation conditions.

Objective: Various studies have recommended parameters for the use of Er:YAG laser for the treatment of enamel and dentis caries; however, none have studied the increase in temperature caused by laser in individual groups of teeth. Summary Background Data: The effect of preparation with Er:YAG laser on the pulp temperature changes is one of the major problems in using the laser for preparation of dental hard tissue. Methods: The authors studied the intrapulpar temperature changes in 10 incisors, 10 canines, 10 premolars and 10 molars during Class V cavity preparation with focused short pulse (250 μs/pulse) and very short pulse (80-120 μs/pulse) Er:YAG laser, using the following parameters: 10 Hz frequency, 500 mJ per pulse, 6 s, 10 mm distance, 25 ml/min water flow, at 23°C and 65% humidity. Results: The greatest increase in temperature was foundin the incisors and the least increase in the molars at both pulse modes. Conclusions:The very short pulse mode caused less of an increase in temperature in the pulp chamber in all teeth than the short pulse mode.

Non-invasive laser therapy is currently frequently used in stomatological practice thanks to its analgesic, antiinflammatory and biostimulating effects. Suitable indications and methodic procedures of the treatment should be established to provide the relevant efficacy of the method. Materials and methods: The source of the beam is a diode (670 nm or 830 nm; 30 mW), energy density 4 - 6 J.cm^-2. We have treasted 1 154 patients in 15 indications. The patients were divided into three groups. The group A included patients, who were treated with therapeutic laser, the group B is control, and group C consisted of patients, who were treated by conventional methods. Results: Our results demonstrated a beneficial contribution of therpeutic laser in some. Conclusion: The success of the laser therapy considerably depends on the time of starting the application. We recommend the treatment of herpetic affections, aphthae, erosions, decubiti of mucous membrane and after difficult extraction.

Following the ethio-pathogenetic approach in the therapeutic management of any pathological process, and being armed with the latest information and practical experience in the newly-developing and very promising field of bioresonance information laser medicine, thereby arose the obvious aim to elaborate a highly effective method of treatment for insulin-dependent diabetes (IDD) or Type I diabetes and non-insulin-dependent diabetes (NIDD) or Type II diabetes with the application of bioresonance information laser method of treatment, which involves the complex integrative use of low-level laser irradiation (LLLI), microwave resonance puncture (MRP) and light-emitting diode chromatotherapy (LEDCT) that would free diabetic patients from life-long insulin injections or hypoglycemic tables and enable them to lead a normal life with a normal or not severely restrained diet.

In scope of Education Ministry Research project solving we have from the end of year 2000 initiated to verify the clinical contribution of laser source emitting the light radiation in the 532 nm wavelength and 10 mW power (green). The study is in progress all the time and therefore results referred-to have to be considered as preliminary. Till the time 105 patients has been treated and the groups are continually completed with new patients.

Variable effects of different forms of light therapy on wound healing have been reported. This preliminary study covers the efficacy of infrared light emitting diodes (LED) in this domain. Cultured embryonic chicken fibroblasts were treated in a controlled, radomised manner. LED irradiation was performed three consecutive days with a wavelength of 950 nm and a power output of 160 mW, at 0,6 cm distance from the fibroblasts. Each treatment lasted 6 minutes, resulting in a surface energy denstiy of 3,2 J/cm². The results indicated that LED treatment does not influence fibroblast proliferation at the applied energy density and irradiation frequency (p=0,474). Meanwhile the effects of LED on wound healing in vivo were studied by treating a surgical incision (6 cm) on the lateral side of the right foot in a male patient. The treatment started after 13 days, when initial stitches were being removed. The same parameters as in the in vitro study were used but the treatment was performed five times. The healing could only be evaluated clinically, the irradiated area (2,6 cm) showed a more appropriate contraction, less discoloration and a less hypertrophic scar than the control area (3,4 cm). The used parameters failed to demonstrate any biological effect of LED irradiation in vitro, although the case study on the other hand illustrated a beneficial effect.

The first employments of Laser therapy for I.P.P. came from back to more than twenty years ago. At the beginning it was employed only in the acute forms as analgesic laser laser was used also as anti-inflammatory following the doses of Low Level Laser Therapy. Than the science tried to use the laser effect remodelling phase of the scars, to make the fibrosis regrade in the chronic forms. Tunable laser in small optical fiber was used for ablation of calcified zones with very good results. For the slight forms were used diode laser 660 and 904 nm, alone ir coupling with CO2 laser with large spot. At first some Author used helium-Neon laser 632. Some of these lasers were combined wtih microiontophoresis and ultrasounds therapy in teh same treatment. Now we use 810 nm surgical diode laser in almost all induratio forms. The immediate results and follow up will be discussed. Thanks to these results we could conclude that IPP laser therapy can be effective in most of the clinic forms. Although the used procedure is subject to improvement.

Objective: The aim of this clinical study is to determine the efficacy of the JR diode laser 904 nm pulsed on pain reduction therapy. Summary Background Data: With respect to pain, the existence of a filter (Rolando's substantia gelatinosa) in the spinal marrow is fundamental. Opening or closing, this filter is able to block transmission of pain impulses to a higher cerebral center. This is in proportion with the A big fibres and C small fibres. The action of the laser influences this mechanism. Additionally, laser interferes in the cytochines (TNf-α , interleukin-1 and interleukin-6) that drive inflammation in the arthritis and are secreted from CD4 e T cells. Low power density laser increases the endorphin synthesis in the dorsal posterior horn of the spinal cord. Besides, laser causes local vasodilatation of the capillaries and an improved circulation of drainage liquids in interstitial space causing an analgesic effect. Methods: Treatment was carried out on 482 cases and 464 patients (274 women and 190 men) in the period between 1987 and 2000. The patients, whose age ranged from 25 to 70, with a mean age of 45 years, were suffering from rheumatic, degenerative and traumatic pathologies as well as cutaneous ulcers. The majority of the patients had been seen by orthopaedists and rheumatologists and had undergone x-ray, ultrasound scanning, TAC, RM examination. All patients had previously received drug-based treatment and/or physiotherapy with poor results. Two thirds were experiencing acute symptomatic pain, while the others presented a chronic pathology with recurrent crises. We used a pulsed JR diode laser, GaAs 904 nm wavelength. Results: Jn the evaluation of the results the following parameters have been considered: disappearance of spontaneous and induced pain, anatomic and functional evaluation of the joints, muscular growth, verbal rating scales, hand dinamometer, patient's pain diary. Very good results were achieved especially with cases of symptomatic osteoarthritis of the cervical vertebrae, with sport-related injuries, with epicondylitis, tendinitis, periarthritis and neuritis. The total relief of pain was achieved in 82% of acute and 65% ofchronic cases. Conclusions: Treatment with 904 nm JR diode laser interrupts the "circulus vitiosus" ofthe origin of the different pains (neuropathic, metabolic, traumatic, toxic, immune-mediated, ischaemic) and its development. LLLT brings a normal physiological condition back to the tissue, thus myofascial pain relief, decreases tension and substantially reduces the symptoms as well as improves the quality of life of the patients. Our fourteen years of experience indicates that LLLT is a low cost, non-invasive method and easy to be applied.

Non-invasive lasertherapy became today an appreciated treatment method. To avoid its degradation, it is necessary that every physician, who indicates it, would pass out the basic course in these problems. So the error danger by its application would be reduced. As we have verified, in every country the education process is different; we don't consider this fact as right. In the Czech Republic the Radiobiologic Society of Czech Medical Society J. E. Purkynje in co-operation with the Institute of Further Physician's Education, having wide experiences in postgraduate education, organizes already five years such courses. The basic course has 20 lessons, in which the graduates are acquainted with physical base of laser, hygienic rulings for working with laser and biologic changes induced by low level laser in the tissue in vivo. A considerable attention is dedicated to clinical practice and practical education on clinical departments in the fields of dermatology, physiotherapy, stomatology and gynaecology. This course is completed with a lecture of the recent marketing in health service. Participants document their knowledge's in the closing test. Every physician can perfect his knowledge's in a continuation course. Our experiences proved that the education in phototherapy in Czech Republic is on high level in comparison with number of other countries.

Background and objective: Cosmeceuticals, chemical peels and collagen injections are used to rejuvenate skin, but none of those methods is effective or permanent. Recently, laser resurfacing has been found to be effective, but the incidence of side effects is relatively high. Last year, the non-ablative wrinkle reduction laser (N-Lite, ICN Photonics, UK) was developed, and there have been several reports about its clinical effectiveness. In this study, we have investigated ultrastructural changes elicited by N-Lite laser exposure. Material and methods: 6 adult volunteers were recruited for this study. They were treated with the N-Lite laser and a single 3-nm punch skin biopsy was obtained immediately after the inadiation, as well as 3 hours and 3 days later. These specimens were examined under an electron microscope. Results: Immediately after the laser exposure, capillary endothelial cells showed marked edema and inflamed mast cells were observed, but erythrocytes were intact. 3 hours after the laser therapy, capillary cells were stagnant and monocytes had moved out into the dermis. 3 days after the laser therapy, interstitial edema around the capillaries was observed, and elaunin fibres were also observed. Melanin granules were observed in fibroblasts and in capillaries. Conclusion: N-Lite laser irradiation leads to marked edema of endothelial cells and dermal coirnective tissue, although endothelial cell necrosis was not observed.

Background: Low-level laser has been used for treatment of ulcer, as well as, pain relief and inflammatory processes. In the present work, the effect of low power laser on mucosal gastric ulceration-induced by indomethacin in rats has been investigated. Materials and Methods: 16 male Sprague Dawley rats were divided into control (8 rats) and laser exposed group (8 rats). After using ether for anesthesia, 30 mg/kg indomethacin was injected subcutaneously. Exposed stomachs received 30 J He-Ne laser. Five hours later animals were killed and their stomachs were checked and observed for presence of ulceration. Results and Discussion: Gastric mucosal ulceration index was significantly greater in the laser-exposed group than control group. (P=0.02) This experiment suggests that low power He-Ne laser intensified acute mucosal ulcer formation by indomethacin. Changes in the prostaglandin content ofthe stomach may be responsible for these results.

Objective: Evaluating the effectiveness of low-level laser therapy (LLLT) in alleviating the symptoms of lumbar spondylolisthesis. Materials and Methods: Laser was irradiated for 2 mm at six symmetric points along the lumbosacral spine and 5 points along the referred point ofpain, six times a week for 2 weeks (890 nm; 8 J/cm2; pulsed at 1500 Hz). Perception of benefit, level of function was assessed by the Oswestry disability index, lumbar mobility range of motion and low back pain intensity. Results and Discussion: Results showed a complete reduction in pain and improvement in function in the patient. This case report suggests that low-level laser therapy (LLLT) could play a role in conservative management of low-grade lumbar spondylolisthesis.

Pilot program for Master's studies on Biomedical Optics has been developed and launched at University of Latvia in 1995. The Curriculum contains several basic subjects like Fundamentals of Biomedical Optics, Medical Lightguides, Anatomy and Physiology, Lasers and Non-coherent Light Sources, Optical Instrumentation for Healthcare, Optical Methods for Patient Treatment, Basic Physics, etc. Special English Terminology and Laboratory-Clinical Praxis are also involved, and the Master Theses is the final step for the degree award. Recently a new extensive short course for medical laser users "Lasers and Bio-optics in Medicine" has been prepared in the PowerPoint format and successfully presented in Latvia, Lithuania and Sweden.

Optimized image formation is an essential step preceding automatic image analysis. We report about an optical device for automatic prescreening of cervical cytologic samples. The system should detect abnormal cells. Using band-pass filtering in the Fourier plane a detection of abnormal cells is possible. The main advantage of this method is its ability ofparallel processing in real time. That means we can handle a large object field at once in a microscope. We use a very simple parameter -the size of the cell nucleus- for a discrimination between normal and abnormal cells. As a typical result the detection of abnormal cells in a Papanicolaou smear by band-pass filtering is showed.

To localize and monitor the blood content in tissue we developed very sensitive photoacoustical detectors. In these detectors a PVdF-layer has been used as piezo-electric material and also fibers for the illumination of the sample are integrated. The resolution is about 20 im in depth and about 50-100 im laterally. The wavelengths ofthe laser light were 532and 1064 nm. With these colors we can measure at different depths in tissue. We will report measurements on real tissue: vessels in chicken breast, in the human arm, and in test animals at various positions.

Background: Non-ablative remodeling has been recently proposed as a new anti-ageing treatment with no downtime. Objective: To evaluate the efficacy and safety of non-ablative skin remodeling with a 1540 nm Er:Glass laser and contact cooling on pen-oral and pen-orbital rhytids at 14 months follow up. Methods: 42 female patients (mean age: 47 years), Fitzpatrick skin types I -IV were treated five times at 6 weeks intervals, and checked 6 months after the last treatment . Patients were evaluated using clinical data, patients satisfaction (scale 1 to 4), digital pictures, ultrasound imaging and profilometry data from silicone imprints in order to quantify the degree of improvement. Results: All subjects reported an improvement in the quality and visual aspect of their skin at 6 months (mean patient's satisfaction : 3,06/4) and they noticed that it was very similar at 14 months after enrollment (mean patient's satisfaction: 2.9/4) . This was confirmed by a 43.2% reduction ofanisotropy (p<O.OO1) six weeks after the 4th treatment, and even 49.5 % reduction 6 weeks after the 5th treatment. Ultrasound imaging demonstrated a 17% increase of the dermis thickness (p<O.OO5) 1 month after the 3rd freatment and still 1 1% increase 6 months after the last treatment. A lack of immediate or late adverse effects was noted at all stages ofthe procedure. Conclusion: This study demonstrated that irradiation with a 1540nm Er:Glass laser emitting in a pulsed mode and coupled with an efficient cooling system , increases dermis thickness, reduces the anisotropy ofthe skin and finally improves clinical aspects. The lack of adverse effects confirmed that all this procedure was safe.

Three possibilities of mid-infrared Er:YAG lasers Q-switching were investigated: mechanical and two electro-optical ones. The mechanical method of Q-switching was proved by using of a rotating mirror placed inside the resonator; Pockels or Kerr cells were used for the electro-optical Q-switching. The Pockels cell was constructed on the basis of the Brewster angle cut LiNb0₃ crystal; the Kerr cell used a ceramic PLZT material. In all the three cases the Er:YAG laser resonator was plan parallel and it consisted of the rear copper mirror and output coupler with 50-70% reflectivity. The Er:YAG crystal was pumped by one xenon flashlamp in a single elliptical silver coated cavity. The generated giant pulse output parameters were the following: the length was measured in the range of 200-400 ns; the output energy was from 10 mJ up to 30 rnJ. With the rotating mirror the output was stable in a wide range ofthe switching interval. All the three cases can be used in applications. The particular Q-switch can be chosen from the point of view of output parameters and construction requirements.

This study was to evaluate the effects of the CVL with low energy and short pulse widths. 18 female mice, C57BL/6 (9-11 weeks old) were distributed into four groups. The control group (CG) wasn't exposed to laser beam . Group L1 had 2 laser expositions with 24 hours gap between them (0.5W). Group L2 had 3 expositions (0.5W and 0.25W) and group L3 had 4 expositions (0.25 W). It was used a CVL prototype (5lOnm, 13 Khz, pulse width of 20 ms and spot size of 0.8cm). 7 days after last laser pulse no groups presented actinic keratosis, tumors or collagen changes. CVL had effective action on pilosebaceous units. High energy with few short pulses induced hair follicles proliferation while low energy with many repetitive short pulses showed increased and specific tissue damage besides hair plugging.

An effort has been made to detect neopterin spectrum in fluorescence of premalignant endometrial tissue and to estimate the number of fluorophores naturally existing in the tissue with fluorescence present above the noise level. Endometrial Tissue fluorescence was measured in vitro by excitation with the third harmonic of Nd YAG laser. Multivariate curve resolution was used for testing neopterin presence in endometrial tissue. Fluorescence spectra ofneopterin was measured and used as a target spectrum for testing. Seven factors -fluorescence ofnatural fluorophores ofendometrial tissue were found to be present above the noise level in the overall autofluorescence. Neopterin concentration may be too low in endometrial tissue to make its fluorescence above the noise level because neopterin spectrum was not found to be among the spectra resolved by multivariate curve resolution. An intensity increase in the neopterin spectrum spectral region in hyperplastic endometrial samples might be associated with neopterin concentration increase.