This project was designed as a preliminary single case series study to investigate the efficacy of combined phototherapy/low intensity laser therapy in the management of neuropathic and ischaemic foot ulceration. After ethical approval was obtained, four patients suffering chronic ulceration were recruited (average wound area = 57.4 ± 4.5 mm2 ) ; all attended the Chiropody clinic, Belfast City Hospital, N Ireland, on a daily basis (5 days per week) for irradiation of wounds for a total of four weeks. After baseline wound surface area readings were obtained, irradiation was carried out in conjunction with routine debridement and dressings; for the former a 31 diode probe (660 nm - 950 nm) was employed with a constant dosage of 4.2 J/cm2 pulsed at 5 kHz. Wound area was recorded using a combination of tracing and planimetry methods. The principal finding for the patients studied was a significant reduction in wound surface area; as a result of treatment, wound area expressed as a percentage of pre-trial values after two and four weeks of treatment were 46.2 ± 15.5% and 24.2 ± 12.0% respectively (mean ± s.e.m). Analysis of these results using a simple Sign test demonstrated such reductions to be statistically significant (p < 0.05); other positive clinical effects were evident. Thus combined therapy at the chosen parameters would seem to be an effective treatment for such patients. Further studies are therefore indicated to establish optimal irradiation parameters under carefully controlled conditions, and to clinically evaluate the efficacy of this modality for wounds of other aetiologies.
We previously constructed the cDNA library of osteoblastic cells using a stepwise subtraction procedure between cells with and without laser irradiation to identify any gene whose expression is enhanced by low level laser irradiation (LLLI). In the present study, we focused on a gene clone obtained from the subtracted cDNA library, designated as #201, which exhibited high homology with the gene coding for F0F1-ATPase subunit-b which is involved in the synthesis of ATP. To confirm the gene, the DNA sequence of the cDNA clone #201 was determined and assessed in DNA databases. The transcription level of the gene was examined by Northern blot analysis. Furthermore, the intracellular ATP content in laser irradiated cells was measured and compared with unirradiated cells. The DNA sequence of #201 clone exhibited 94.9% and 94.1% homology with rat and human F0F1-ATPase subunit-b gene, respectively. Higher F0F1-ATPase subunit-b mRNA levels were observed in laser irradiated cells compared with those in unirradiated cells. Furthermore, the content of ATP in laser irradiated cells was higher than that in unirradiated cells. These findings suggest that LLLI may play a principal role in accelerating ATP synthesis by stimulating the gene expression of F0F1-ATPase.
Although recent studies show that low reactive-level laser irradiation has some effects on several immune responses, few studies have examined the effect of diode laser irradiation on picryl contact sensitivity, a kind of cellular immunity. This study consisted of three experiments to evaluate the effect of diode laser irradiation (DLI) on picryl contact sensitivity in mice. First, (Exp.1), the laser irradiation site (right ear) was the same as the challenge site (right ear). Second, (Exp.2), the irradiation site (proximal portion of tail) was remote from the challenge site (right ear) Third, (Exp.3) we evaluated the penetration of diode laser energy through the irradiation site (right ear) compared with a range of incident powers. The effect of DLI for picryl contact sensitivity was evaluated with measurements of any increase of the ear thickness. The irradiation times in Exp.1 and Exp.2 were 15, 30 and 60 min. The results showed that DLI suppressed the cutaneous inflammation of picryl contact sensitivity in an exposure time dependent manner and this suppressive effect was restricted to within the irradiation site. 60 min irradiation in the challenge site was remarkably effective, however irradiation of the remote site did not affect the ear thickness increments in the challenge site. The penetration of laser energy through the ear was almost 50% of its output power in the whole range of powers tested.
Persistent skin ulcers are still a major problem for the plastic and reconstructive surgeon. These ulcers of various aetiologies are often resistant to conventional therapeutic methodologies, and present both patient and surgeon with severe problems. Low level laser therapy (LLLT) has been proved to accelerate wound healing by enhancing blood flow, macrophage activity and lymphatic drainage in the inflammatory stage; by increasing fibroblast proliferation and collagen deposition in the proliferative stage; by encouraging more fibroblast to myofibroblast transformation in the contractile stage; and by assisting with remodelling in the final stage of repair. It was considered that these LLLT-associated actions, coupled with others, would be of assistance in treating persistent ulcers in a painless, side-effect free and noninvasive manner. The laser used was a near infrared 830 nm gallium aluminium arsenide (GaAlAs) semiconductor laser delivering 150 mW in continuous wave. The laser was applied in the contact mode for 15 to 30 sec per point, irradiating the intact skin around the periphery of the ulcer. The incident energy density was approximately 66 J/cm2 or 132 J/cm2 per point, depending on the exposure time. Nine representative case reports are presented of persistent therapy-resistant ulcers of a variety of aetiologies which responded very well to 830 nm diode LLLT. Although further research is needed to elucidate completely the mechanisms and pathways of LLLT in wound healing enhancement, enough has been scientifically proved to date to justify the application of LLLT for persistent ulcers as a safe, effective, painless and side effect free modality, particularly when used as an adjunctive therapy together with good wound care.
Polymorphonuclear leukocytes (PMNL) from ten diabetic cases were tested for phagocytic activity by the NBT reduction test and the activity was found to be grossly reduced (p < 0.001) in comparison to PMNL from matched healthy volunteers. In vitro experiments were then carried out on PMNL from 2l diabetic subjects to find out if the phagocytic activity in terms of intracellular killing of phagocytosed challenged bacteria was improved following irradiation with low incident doses of nitrogen (N2) laser energy. It was demonstrated that N2 laser exposure for 15 minutes at an output power of 6 mW, λ = 337 nm, could accentuate the killing of internalized Staphylococcus aureus when compared to the non-irradiated control PMNL (p < 0.001). Furthermore, it was also seen that this enhanced phagocytic activity occurred without affecting the viability of the PMNL cells. Thus to conclude, N2 laser therapy accentuated the in vitro phagocytic activity in neutrophils from diabetic patients. This study may have therapeutic potential in various groups of immunocompromised patients.
A diode laser system (Mochida Luketron 150 Model 1003, Matsushita Electrical Company, Tokyo, Japan) was used for the treatment of 17 patients with nail disorders: nine patients with chronic paronychia and eight patients with ingrown nail (onychocryptosis). We treated stage I of ingrown nails (following the classification of Zaias N) or subcutaneous ingrown toe nails (after the classification of Baran R & Dawber RPR) with LLLT. The system emits a 150 mW continuous wave beam at 830 nm in the near infrared on a small round spot of approximately 1 cm in diameter, delivering an incident dose of approximately 45 J/cm2 per spot. We applied the laser beam to six spots on the fingers of the chronic paronychia patients and to fifteen spots on the fingers of the patients with ingrown nails for fifteen seconds per point. The effect was evaluated and marked by the patients themselves according to the clinical findings on a scale of from zero to ten where ten represented the clinical findings at the first visit and zero represented complete recovery. The final post-LLLT scores of 9 patients with chronic paronychia were as follows: 2, 3 and 7, one patient each; 0, 4 and 5, two patients each. Out of 8 patients with ingrown nails, the scores were as follows: 3, 5 and 7, one patient each; 0, five patients. To reach the treatment endpoint, meaning complete cure or the point after which further LLLT produced no significant improvement, chronic paronychia required on average 20.4 ± 18.32 (mean ± SD) days of therapy (range 5 days to 62 days) and ingrown nail required 5.0 ± 4.1 days (range 2 days to 14 days), respectively. No adverse side effects were reported for any patient. From this preliminary study, the authors conclude that 830 nm diode LLLT applied at the parameters in the present study is effective for chronic paronychia and particularly effective for the therapy of early stage ingrown nails.