Stimulatory effect of low-power density He-Ne laser radiation on human fibroblasts in vitro

Cultures of human embryonic fibroblasts in vitro were subjected to helium-neon laser single and double irradiation to investigate the influence of low-energy laser irradiation on fibroblast proliferation. Mean increase in the cell number values of irradiated cells were compared with increase values of non-irradiated control samples of fibroblasts. He-Ne laser was used as a coherent source of monochromatic radiation at 632.8 nm, and Petri-dishes with cultured fibroblasts were irradiated in way to receive radiation of energy doses of 0.5; 1; 1.5 and 2J/cm2. Single He-Ne laser irradiation exhibited a significant stimulation effect on human fibroblast proliferation in cell-culture.     

Controlled temperature tissue fusion: argon laser welding of rat intestine in vivo. Part one

BACKGROUND AND OBJECTIVE: Thermal denaturation of proteins is recognized as a rate process governed by the local temperature-time response. Since rate processes are exponential with temperature, laser-assisted tissue welding was performed with and without temperature feedback control (TFC) to investigate the efficacy of temperature feedback in enhancing the photothermal welding process in vivo. STUDY DESIGN/MATERIALS AND METHODS: An automated system was developed for temperature feedback controlled laser irradiation. An experimental device incorporating co-aligned laser delivery and temperature detection was used to perform argon laser welded (with and without TFC) enterotomies. The weld strength and histology of laser welded and control sutured enterotomies were compared in an in vivo rat model. Animals (n = 41) were sacrificed at 1, 3, 7, and 21 days postoperatively, and the anastomotic site was removed for bursting/leaking pressure measurements and histological examination. RESULTS: Laser-welded (with and without TFC) and control sutured anastomoses in surviving animals healed comparably. Some laser-welded anastomoses without TFC ruptured spontaneously (4 out of 15) leading to the animals' death within the first 24-36 hours postoperatively. None of the animals in the other groups had this problem (control suture 0/6; laser with TFC 1 leak/8). The bursting/leaking pressures of the laser welded anastomoses were not significantly different than those of the sutured controls. CONCLUSION: TFC improves the quality of laser-welded rat intestinal anastomoses in vivo in the critical first postoperative 36 hours.     

In vitro synthesis of prostaglandin E2 by synovial tissue after helium-neon laser radiation in rheumatoid arthritis

This paper reports the effect of helium-neon laser radiation (power of 5 mW and 632.8 nm wave length) on the synthesis of PGE2 in vitro in synovial tissue of biopsy samples of knee joints in patients with chronic rheumatoid arthritis stages II or III. Twelve patients were studied. Each patient received 15 applications of He-Ne laser. Eleven points for He-Ne laser applications were selected in one of the affected knees. The energy density used was 8 J/cm2 per application point. The He-Ne laser therapy reduced the synthesis of PGE2. The analysis of the data revealed a statistically significant difference between the levels of the synthesis of PGE2 before treatment (17.69 +/- 2.65 ng mg-1 of dry tissue h-1) and after treatment (13.85 +/- 2.73 ng mg-1 of dry tissue h-1), with p < 0.01 comparing mean values. This was also accompanied by relief of pain (91.6%), and a favorable subjective report from the patient. We conclude that PGE2 is a quantifiable parameter that could explain what causes pain relief in patients with rheumatoid arthritis that are treated with He-Ne laser.     

Comparison of wound healing process using Argon and Krypton lasers

OBJECTIVE: We compared the wound healing process on Sprague-Dawley rats between Argon Laser and Krypton Laser, and calculated the laser actual doses after correction on wound healing on rats and estimated the clinical doses on wound healing for human skin. SUMMARY BACKGROUND DATA: Laboratory work provided some support for the use of low-intensity laser radiation in wound healing. Some studies found that laser irradiation may either enhance, inhibit, or has no effect on the function of a variety of microorganisms and cells. Animal studies also offered some basis for treatment. Improvements, particularly in the earliest phases of wound healing, have been reported following laser irradiation. METHODS: We used Argon Laser (488-514 nm) and Krypton Laser (670 nm) in the study. The laser beam was delivered through a system of fiber optic in Argon Laser and reflector in Krypton Laser. The rats treated were restrained in a Plexiglas cage without anesthesia during the laser irradiation period. The percentage of the wound healing acceleration in days and size, actual doses, and estimated clinical doses were calculated as follows: AccD = (1-TD/CD) x 100%, AccS = (1-TA/CA) x 100%, AD = D(in) - D(gl) - D(SR) and ECD = AD = D(sr), respectively. RESULTS: The acceleration effects of wound healing in days (AccD) were 22.93% and 14.54%, size reductions (AccS) were 41.93% and 30.41% at the optimal stimulative incident dose of 20 J/cm2. Zero bioactivation shown at the incident doses of 80 J/cm2 and 100 J/cm2. The inhibitory effects of wound healing in days were -7.72% and -3.37%, in size reduction were -13.35% and -12.88% at the maximal inhibitory incident dose of 140 J/cm2 for Argon and Krypton Lasers, respectively. The actual doses were 5.21 J/cm2 and 4.03 J/cm2, the estimated clinical doses were 5.50 J/cm2 and 4.25 J/cm2 at optimal stimulative incident dose 20 J/cm2 for Argon and Krypton Lasers, respectively. CONCLUSIONS: Low power laser therapy at the appropriate dosimetric parameters can provide the acceleration effects of wound healing on rats. The effects were dependent with the doses and laser wavelengths used. In this experiment, the optimum stimulative dose was 20 J/cm2 and the Argon Laser with 488 nm was more effective than the Krypton Laser with 670 nm. The zero bioactivation and inhibition effect of wound healing on rats occurred in Argon Laser and Krypton Laser.     

Maintenance of aerobic capacity during recovery from right foot Jones fracture: a case report

PURPOSE: We sought to evaluate the effectiveness of continued training with deep water running (DWR) on the healing process from a lower leg fracture in maintaining aerobic fitness. CASE SUMMARY: An elite male middle distance runner presented with a Jones fracture of the right foot. The patient opted for nonsurgical treatment. Non-weight-bearing immobilization in a cast proceeded for 14 weeks. The patient continued training by simulating land running and team land workouts with DWR. DWR was the principal mode of exercise through week 24. Physiological and race performance assessments noted a progressive and complete return to preinjury fitness and performance levels. DISCUSSION: DWR can be used by competitive runners during a rehabilitative period to maintain fitness and does not impede the healing process. In developing a DWR regimen, it should be noted that the exercise heart rate when working above the ventilatory threshold will be approximately 12 bpm lower in water. RELEVANCE: DWR may be feasible for maintenance of competitive edge during lower trunk injury rehabilitation.     

Promotion of muscle regeneration in the toad (Bufo viridis) gastrocnemius muscle by low-energy laser irradiation

The effect of low-energy laser (He-Ne) irradiation on the process of skeletal muscle regeneration after cold injury to the gastrocnemius muscle of the toad (Bufo viridis) was studied using quantitative histological and morphometric methods. The injured zones in the experimental toads were subjected to five direct He-Ne laser (632.8 nm wavelength) irradiations (6.0 mW for 2.3 min) every alternate day starting on the fourth day postinjury. Muscles that were injured as above, and subjected to red-light irradiation, served as a control group. Morphometric analysis was performed on histological sections of injured areas at 9, 14, and 30 days postinjury. At 9 days postinjury, mononucleated cells populated 69.3% +/- 16.8% of the total area of injury. Thereafter, their volume fraction (percent of total injured zone) decreased gradually but more rapidly in the laser-irradiated muscle than in the control. The volume fraction of the myotubes in the laser-irradiated muscles at 9 days of muscle regeneration was significantly higher (7.0% +/- 2.2%) than in the control muscle (1.2% +/- 0.4%). Young myofibers in the laser-irradiated muscles populated 15.5% +/- 7.9% and 65.0% +/- 9.5% of the injured area at 9 and 14 days of muscle regeneration, respectively, while in control muscles these structures were not evident at 9 days and made up only 5.3% +/- 2.9% of the traumatized area at 14 days postinjury. The volume fraction of the young myofibers further increased by 30 days of muscle regeneration making up 75.7% +/- 13.2% of the traumatized area, while in the laser-irradiated muscles most of the injured zone was filled with mature muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Is transglutaminase the mediator between antimalarial drugs and psoriasis?

The object of this experimental study was to investigate the influence of low-energy He-Ne laser on the motor nerve cells of the spinal cord. The experimental study included as follws: (1) Four rabbits were used in this experiment. The L5-6 spinal cord segment was irradiated by He-Ne laser percutaneously, the nerve velocity of the comon peroneal nerve was measured in order to determine the function of the spinal motor nerve cells when the peripheral nerve was intact. (2) The common peroneal nerve was transected on one side wothout repair, two weeks after laser irradiation, the grey mater of the spinal cord of L5-6 segment was procured for electronic microscopic examination. (3) The common peroneal nerve on the contralateral side was transected and followed by end-to-end anastomosis, and laser irradiation was done on the same spinal cord segment. Two weeks after irradiation, the nerve velocity of the common peroneal nerve and the toe expanding test were investigated. The results were: (1) the He-Ne laser can influence the spinal motor nerve cells function as expressed by latent rate when the peripherial nerve is intact. i.e. the nerve velocity is slower than mormal, and the amplitude is markedly decreared. (2) the change of the microstructure of the spinal motor nerve cells is comparatively slight in the 10 and 15 minutes groups. (3) the recovery of the nerve velocity and the toe expansion are more earlier in the 15 min. group. In short, the low-energy He-Ne laser can influence the function of the spinal motor nerve cells.     

Effect of photodynamic therapy on the healing of a rat skin flap and its implication for head and neck reconstructive surgery

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) may as adjuvant therapy by used to reduce tumor recurrence in the head and neck with surgery, given intraoperatively after resection. A concern with the use of intraoperative PDT is the possible effect on wound healing, especially on the healing of myocutaneous skin flaps, which are widely used to reconstruct defects following resections for head and neck cancer. STUDY DESIGN/ MATERIALS AND METHODS: A flap, based on the inferior epigastric artery, was prepared in thirty male Lewis rats. Group I did not receive any further treatment but the wound was left open for 20 minutes. Group II was injected with 5mg/kg Photofrin, 48 hours prior to the operation and also did not receive any further treatment. The wound bed and wound borders of group III were treated with 630nm light of different dosages, delivered by an argon dye laser. Animals in group IV received 5mg/kg Photofrin 48 hours prior to the operation and their wound beds were treated with the same light dosages as group III. After the treatment all flaps were replaced into the wound bed and the incisions were closed. Biopsies for histological analysis were taken at several time points; and on day 21, biopsies for wound tensile strength measurements were taken. RESULTS: The wound healing in group I, II, and III appeared normal and there were no differences seen between these groups. Also, the tensile strength did not differ significantly. The flaps of group IV showed serous effusion, epidermal necrosis, and weaker tensile strength (P = .04 and .02 for the light doses of 50 J/sq cm and 75 J/sq cm respectively) at a specific time point. CONCLUSION: The results of this study demonstrate that PDT given immediately before flap reconstruction will result in delayed wound healing. These results should be considered when contemplating the use of PDT as adjuvant intraoperative therapy for tumor surgery requiring flap reconstruction after ablative surgery.     

Laser Doppler imaging and capillary microscopy in ischemic ulcers

The local distribution of laser Doppler flux (mainly thermoregulatory perfusion) and capillary density (nutritive circulation) within 25 ischemic leg ulcers and their adjacent skin were investigated. For this purpose the technique of laser Doppler imaging and capillary microscopy were applied. In each ulcer a non granulation tissue area (NGTA), a granulation tissue area (GTA) and in adjacent skin a skin area (SA) were defined. In these areas the average laser Doppler area flux (arbitrary units, AU) and the number of capillaries/mm2 were determined for each patient. The mean+/-S.D. of laser Doppler area fluxes were: NGTA 1.30+/-1.93, GTA 2.13+/-1.53 and SA 1.21+/-0.77 AU, respectively. The differences between GTA and NGTA or SA was statistically significant (p < 0.001, each) The mean+/-S.D. of capillary densities were as follows: NGTA: 0.56+/-2.06, GTA 6.76+/-8.39 and SA 16.80+/-7.38 capillaries/mm2, respectively. The following differences were statistically significant: NGTA versus GTA (p < 0.01) and SA versus NGTA or GTA (p < 0.001, each). In conclusion following characteristics of the three areas can be described: In NGTA low laser Doppler area flux is combined with very low capillary density (ulcer area without healing). In GTA the highest laser Doppler area flux of all three areas and an intermediate capillary density (wound healing) is found. In SA an intermediate laser Doppler area flux is associated with the highest capillary density of all three areas with the healing process nearly completed and no granulation tissue.     

A prospective randomized trial of topical soluble 0.1% indomethacin versus 0.1% diclofenac versus placebo for the control of pain following excimer laser photorefractive keratectomy

BACKGROUND AND OBJECTIVE: To compare the safety and efficacy of topical nonsteroidal antiinflammatory drugs (NSAIDs) for the control of pain after excimer laser photorefractive keratectomy (PRK). PATIENTS AND METHODS: One hundred twenty informed patients were enrolled in a double-masked, randomized, comparative study and assigned to either 0.1% indomethacin, 0.1% diclofenac, or placebo treatment. Subjective postoperative pain, symptoms, re-epithelialization rate, and systemic medications were monitored for 2 days following photoablation. RESULTS: Compared with the placebo, 0.1% indomethacin solution significantly reduced pain on the day of surgery (D0) (P < .05), whereas 0.1% diclofenac did not reach a significant level (P = .46). At D0, analgesic intake by the oral route was significantly greater in the placebo group (P < .05). Severe photophobia was significantly less frequent in the group treated with 0.1% indomethacin (P < .05). Corneal wound healing was significantly delayed in the patients treated with 0.1% diclofenac at D2 as compared with other groups (P = .04). CONCLUSION: Topical 0.1% indomethacin solution helps control the pain induced by excimer laser photoablation of the cornea without any detrimental effect to the corneal epithelial wound healing.     

Cervical spine abnormalities in professional singers

BACKGROUND AND OBJECTIVE: The purpose of this study was to determine irradiation parameters of a 780 nm low power CW diode laser (6.5 mW) leading to enhanced proliferation of cultured normal human keratinocytes (NHK). The possible role of reactive oxygen species (ROS) in this response was evaluated. STUDY DESIGN/MATERIALS AND METHODS: NHK were exposed to a single dose of 0 to 3.6 J/cm2 (0-180 sec) of irradiation. Proliferation parameters studied were: incorporation of 3H-thymidine during 6-24 hr following irradiation; percentage of dividing cells and number of cells, 24 hr and 48 hr following irradiation, respectively. RESULTS: Proliferation of NHK exposed to 0.45-0.95 J/cm2 was significantly enhanced by 1.3-1.9-folds relative to sham-irradiated controls, as inferred from parameters studied. Exposure to other energy densities was considerably less effective in enhancing proliferation parameters. Added enzymatic antioxidants, superoxide dismutase or catalase, scavenging superoxide anions and H2O2, suppressed this enhanced proliferation. Added scavengers (alpha-tocopherol acetate, scavenging lipid peroxidation, or sodium azide, histidine, mannitol, scavenging singlet oxygen, superoxide anions, and hydroxyl radicals, respectively), or N-acetyl cysteine, the thiol-reducing agent, suppressed the response, but to different extents. CONCLUSIONS: The results indicate that 780 nm low power diode laser irradiation enhanced keratinocytes proliferation in vitro, with an apparent involvement of ROS in this response, and comparably, might be used to promote their proliferation in vivo to enhance wound healing.     

Clinical application of the distally based medial adipofascial flap for soft tissue defects on the lower half of the leg

OBJECTIVE: Reconstruction of soft tissue defects on the lower half of the leg. DESIGN: The distally based medial adipofascial flap nourished by the lower perforator originating from the posterior tibial artery was harvested, and the pivot point of flap transposition is 9 to 12 cm above the tip of the medial malleolus. MATERIALS AND METHODS: Twelve cases of open tibial fracture associated with soft tissue defects on the lower half of the leg were reconstructed with this flap. The cases consisted of ten males and two females, and their ages ranged from 16 to 71 (averaging 41 years). MEASUREMENTS AND MAIN RESULTS: Size of the flap varied from 4 x 7 cm to 5 x 18 cm. Eleven flaps had good perfusion and survived completely. Tip necrosis of the flap occurred in one case. In the early postoperative period, take of the meshed split-thickness skin graft on the flap was not complete. All wounds, however, were resurfaced completely without the need of a second grafting. Discharging sinuses occurred in one case, which was managed by removal of infected bony fragments. All the donor sites were closed primarily, and desquamation of wound edges occurred occasionally. CONCLUSIONS: The distally based medial adipofascial flap was a reliable and effect local flap for the reconstruction of soft tissue defects on the lower half of the leg.     

Effect of insulin-like growth factor-1 on zygomatic arch bone regeneration: a preliminary histological and histometric study

A number of physicians have attempted to pharmacologically manipulate the healing of bony fractures with a variety of agents such as growth hormone, thyroxine, chondroitin sulfate, and parathyroid hormone. Thus far, results from these experiments have been inconclusive. Previous research dealing with insulin-like growth factors has centered on cultures of osteoblast-like cells and has demonstrated a stimulatory effect on bone collagen synthesis, which may in fact play a critical role in the process of bone formation itself. The purpose of this investigation was to examine the effects of a genetically engineered growth factor, insulin growth factor type I, on midfacial fracture healing. In 24 adult male Sprague-Dawley rats, a standardized defect was created within the midportion of each zygomatic arch. One-half were treated with insulin growth factor type I administered with an osmotic infusion pump and the other half served as control subjects. At 2, 4, 8, and 12 weeks, animals from each group were killed and specimens of the defect obtained. Data were collected from radiographs and histological studies to compare the extent of bony repair. From this study, it appears that insulin growth factor type I could exert a potentiating effect on the repair of midfacial bone defects.     

Synthesis of arylidenehydrazono- and glycopyranosylhydrazino-sulfonylbenzylidene-2,4-imidazolidinediones as potential antiviral and antitumoral agents

Low-intensity pulsed ultrasound recently has been shown to accelerate long bone fracture healing, but its effect on bone growth and development is unknown. The longitudinal growth and bone density of the femur and tibia in young rats was measured after application of an ultrasound transducer emitting 1.5-MHz pulsed ultrasound (30 mW/cm2, SATA) for 20 min/day. After 28 days, no length difference was detected (< or = 2%) compared to the sham-treated leg or to unexposed controls. Also, no significant difference in bone mineral density (BMD) of the femur or tibia was found (< or = 6%). In a repeated experiment in which a periosteal trauma stimulus was created in the femoral diaphysis, the ultrasound also had no effect on growth or BMD. This results suggests that physeal bone growth is far less sensitive to this level of ultrasound application than is fracture repair. This may be related to the cascade of cellular events and regulatory factors that are present after a fracture.     

Morphologic changes in collagen fibers after 830 nm diode laser welding

BACKGROUND AND OBJECTIVE: The mechanism of laser tissue welding is elusive, but collagen transitions are somehow involved. Collagen fiber modifications observed after 830 nm diode laser welding are presented in this study. STUDY DESIGN/MATERIALS AND METHODS: A 830 nm diode laser assisted longitudinal aortorrhaphy was performed on 37 Wistar rats, with shots of 0.5 W in power, 8 sec in duration and 250 W/cm2 in irradiance. Energy utilized ranged from 400-550 J/ mm2 for 1 cm-length of anastomosis. After laser welding, histological modifications in collagen fibers were observed through optic, scanning electron, and electron microscopic examination. RESULTS: After laser welding, collagen fibers lost a proportion of birefringence. Under electron microscope, the different changes in collagen fibers were visualized being either fused, "roped," swollen, or dissolved, surrounded by normal ones situated in the same zone. CONCLUSION: These data suggest that diode laser heating denatured part of the collagenic fibers, and that these morphologic changes play an important role in laser welding.     

Skin resurfacing of facial rhytides and scars with the 90-microsecond short pulse CO2 laser. Comparison to the 900-microsecond dwell time CO2 lasers and clinical experience

BACKGROUND: Carbon dioxide lasers that produce either short pulses or scanned continuous beams have been used for skin resurfacing to improve wrinkles or scars. Using a high peak power, short pulse CO2 laser can produce clinically effective results with minimal thermal damage. OBJECTIVE: To evaluate the effectiveness of skin resurfacing using the 90-microsecond pulse duration CO2 laser compared to other laser systems. Erythema, healing time, complications, and histological measurement of the depth of ablation and thermal damage per pass with this system were also assessed. METHODS: Forty-one patients with facial rhytides and scars underwent resurfacing with a 90 microseconds pulse duration CO2 laser. Using patient survey, patients were evaluated for effectiveness of therapy, healing time, and complication rates. Comparisons of histologic and clinical findings were made with different short pulse CO2 lasers. RESULTS: Healing time, duration of erythema, and post-operative pain were less with the 90 microseconds pulse CO2 laser than with the 900-microsecond dwell time and 950-microsecond pulse duration lasers, while effectiveness was comparable. Complications were few with the 90-microsecond pulse laser, including three patients (9.1%) developing hyperpigmentation. One pass with the 90-microsecond pulse duration CO2 laser produced 100 microns of ablation with 17 microns of thermal damage. Ablation and damage were additive so that, by six passes, ablation depth was 350 microns and depth of thermal damage was 63 microns. This thermal damage is less than that reported with lasers having a longer pulse duration or dwell time with comparable depths of vaporization. CONCLUSION: Treatment with the 90-microsecond pulse duration laser results in a more rapid healing time and shorter duration erythema. The clinical improvements in wrinkles and sun damage were comparable. The 90-microsecond pulse duration laser provides an effective, predictable, and safe means of improving facial rhytides and scars.     

The reduction of humeral fracture in pigeons with intramedullary poly (methyl methacrylate) and neutralization plate fixation

The reduction of experimental humeral fracture in pigeons was performed with intramedullary bone cement (poly (methyl methacrylate): PMMA) and neutralization plate fixation to investigate the effect on bone fracture healing and the recovery of flying ability. As a result, neither plate nor bone cement fixation held for more than 2 weeks, but not refracture was observed in any cases with both plate and bone cement. In the latter group, it was confirmed by flight tests that almost normal flying ability was recovered in 6 weeks. In pathological findings, blood supply to the fractured ends recovered within 2 weeks and no cortical bone necrosis was observed at the time except for a disturbance of endosteal callus formation. The process of fracture healing on the plate side took place slightly later than that on the non-plate side, and when much PMMA remained between the fractured ends of the cortical bone the bone formation became spongioid. In view of the quick recovery of flying ability, however, plate and bone cement fixation is considered appropriate to prevent the displacement of a humeral fracture in the pigeon.     

Use of magnetic resonance cholangiography in the diagnosis of choledocholithiasis: prospective comparison with a reference imaging method

OBJECTIVES: Evaluate cartilaginous healing in rabbits in response to surgically created thyroid cartilage fractures. Compare healing between laryngeal fracture repair techniques. STUDY DESIGN: Animal model. MATERIALS AND METHODS: Laryngectomy specimens were analyzed at 10 weeks, following paired wire fixation (n = 7) and miniplate fixation (n = 7) of thyroid cartilage fractures. RESULTS: Cartilaginous unions were present in all seven of the miniplated repairs, while fibrous unions were present in six of the wired repairs. The measure of distraction at the fracture site was significantly greater in the wired repairs compared with the plated repairs (P = .005). Furthermore, in five of seven miniplated repairs no distraction at the healed fracture site was present. CONCLUSIONS: The results demonstrate the ease, tolerability, and superiority of the miniplate fixation technique for the thyroid cartilage fractures, based on a rabbit model.     

Integrating traditional beliefs with western practice

176 patients with myocardial infarction were subjected to a sequence of tests: an original gravimetric test on the disease day 7-10, bicycle ergometry on day 12-20, repeated bicycle ergometry on days 30-35 and 100-120. The results of the investigations performed in different times were interrelated. This helped to make accurate prognosis of recovering ability in 85% of patients. This system of dynamic control demonstrated that the greatest positive effects on exercise tolerance are reached in combined use of intravenous blood radiation with He-Ne laser and combined chemotherapy. Nitroglycerin+heparin combination is the least effective. Nitroglycerin+heparin in combination with metabolism correctors is of moderate efficacy.