Effects of Low-Intensity Polarized
Visible Laser Radiation on Skin Burns: A Light Microscopy Study. Journal
of Clinical Laser Medicine and Surgery. 2004; 22 (1): 59-66.
Simoes-Ribeiro M, Teixeira Da Silva D, Nabuco De Araujo C E et al.
This study was carried out to investigate the influence of low-intensity
polarized visible laser radiation on the acceleration of skin wound
healing. Low-level laser therapy at adequate wavelength, intensity,
and dose can accelerate tissue repair. However, there is still unclear
information about light characteristics, such as coherence and polarization.
Some studies indicate that linearly polarized light can survive through
long propagation distance in biological tissue. Three burns about
6 mm in diameter were created on the back of rats with liquid N(2).
Lesion "L(//)" was irradiated by He-Ne laser (X= 632.8 nm),
D= 1.0 J/cm(2), with linear polarization parallel to the spinal column
of the rat. Lesion "L(//)" was irradiated using the same
laser and dose, but the light polarization was aligned perpendicularly
to the relative orientation. Lesion "C" was not irradiated
in order to be considered as control. The animals were sacrificed
at day 3-17 after lesion creation. Samples were collected and prepared
for histological analysis. Results: Histological analysis showed that
the healing of irradiated wounds was faster than that of non-irradiated
wounds. Moreover, it was observed that skin wound repair is dependent
on polarization orientation with respect to a referential axis as
the animal's spinal column. Consequently, "L(//)" was completely
healed after 17 days, whereas "L((perpendicular))" showed
a moderate degree of healing after the same period. These results
indicate that the relative direction of the laser polarization plays
an important role in the wound healing process when highly coherent
He-Ne laser is used.
[Laser therapy of duodenal
ulcers: effect on indices of microcirculation, cell membrane permeability
and homeostasis of trace elements]. Lazernaia terapiia iazvennoibolezni:
vliianie na pokazateli mikrotsirkuliatsii, pronitsaemosti kletochnykh
membran i mikroelementnogo gomeostaza. Eksperimental'naeiia i klinicheskaeiia
gastrocenterologieiia. 2003; (5): 45-50.
Amirov N B.
123 patients with duodenal ulcer were examined. Laser therapy (LT)
was included in the complex therapy for 89 of the patients. 34 patients
underwent only traditional drug therapy and formed a control group.
LT was carried out by 2 ways: intracavitary - by ulcer defect irradiation
with the light guide through the gastroscope biopsy canal and helium-neon
laser (HNL), and non-invasive--through the front abdominal wall in
the corresponding areas, which was made by infrared laser (IRL). The
comparison of two groups established that by including LT in the complex
therapy for DU patients, the dynamics of clinical and laboratorial
data is essential better than during traditional drug treatment (TMT).
It was established that the inclusion of LT in the duodenal ulcer
treatment has a positive impact on the course of the disease. This
impact was displayed as faster reverse development of clinical symptoms,
positive laboratory and instrumental data dynamics, blood serum microelements
content normalization, membrane permeability increase by indicators
of Na-Li counter-transport in the erythrocytes membrane and microcirculation
improvement, mainly in the intravascular section.
Photostimulation of coronary
arteries with low power laser radiation: preliminary results for a
new method in invasive cardiology therapy.
Medical Science Monitor. 2003; 9 (7): 335-339.
Derkacz A,Bialy D, Protasiewicz Marcin et al.
The main problem after percutaneous coronary intervention (PCI) is
restenosis affecting the site where dilatation is performed. In order
to minimize its occurrence, the method of intravascular laser photostimulation
(LP) with low power irradiation has been developed. The new procedure
is carried out during PCI. A special setup was prepared for intravascular
photostimulation with 808 nm wavelength laser diode and special diffuser,
delivering the laser light into the coronary artery. The construction
of the device makes it possible to irradiate the coronary artery in
the place of previously performed of dilatation, in a satisfactory
and programmable manner and with uniform intensity. We describe our
own, unique LP procedure. Two pilot LP procedures carried out in our
clinic are described here. The patients were diagnosed before treatment
and followed up three and six months after the LP procedure with non
invasive tests. After six months, a control angiography was also performed.
The procedures were well tolerated. In both cases the follow-up examinations
showed no evidence of restenosis. The new, innovative technique of
intravascular low power laser photostimulation is a relatively inexpensive
and easy to use treatment method. No negative side effects were observed
after two procedures. The results obtained are very promising. Because
the group of treated patients is still too small, the results cannot
yet be subjected to statistical analysis.
[Low power laser biostimulation in the treatment of bronchial
asthma]. Biostimulacija laserom niske snage u lecenju bronhijalne
astme.
Medicinski pregled. 2003; 56 (9-10): 413-418.
Milojevic M, Kuruc V.
The investigation was aimed at defining therapeutic effects of low
power laser irradiation by stimulating acupuncture points or local
treatment of asthma. A prospective analysis included 50 patients treated
during 2000, 2001 and 2002. Together with conservative treatment of
present disease, these patients were treated with laser stimulation
of acupuncture points in duration of ten days. During treatment changes
of functional respiratory parameters were recorded. Results were compared
with those in the control group. The control group consisted of the
same number of patients and differed from the examination group only
by not using laser stimulation. Patients with bronchial asthma presented
with significant improvement of all estimated lung function parameters
just 30 minutes after laser stimulation. Improvements achieved on
the third and the tenth day of treatment were significantly higher)
in the examination group in comparison with the control group. Further
investigation confirmed that improvement of measured lung function
parameters was significantly higher in younger patients, in patients
whose disease lasted shorter, as well as in women. Patients with asthma,
who were treated every three months for a one year period, presented
with significantly lower frequency and intensity of attacks. The mechanism
of laser stimulation activity in treatment of bronchial asthma is
explained in detail, correlating our results to those obtained by
other authors. A ten-day course of low-power laser stimulation of
acupuncture points in patients with bronchial asthma improves both
the lung function and gas exchange parameters. Positive effects of
laser treatment inpatients with bronchial asthma are achieved in a
short time and they last long, for several weeks, even months. Successive
laser stimulation in asthmatics prolongs periods of remission and
decreases the severity of asthmatic attacks. Better positive effects
of laser stimulation are achieved in younger asthmatics, in those
with shorter disease history and in female patients. There is a negative
correlation between effects of laser stimulation and patients' age
and disease history. However, these characteristics do not affect
response rate and speed but positive laser stimulation effects are
achieved in a shorter period in female asthmatics.
Effects of the 650 nm laser stimulation, utilizing clinical
doses for proliferation
of cultured human fibroblasts. (Efecto de la estimulación láser
de 650 nm, utilizando dosis de uso clínico, sobre la proliferación
de fibroblastos humanos cultivados.)
Lomelí-Rivas A, Krötzsch E, Michtchenko A.
Low-level laser stimulation has been used successfully in the treatment
of wound healing, and other diseases. Fibroblasts are cells involved
in tissue repair, it is needed adequate laser doses for fibroblasts
stimulation. The objective of this study is to know the effects of
? = 650 nm laser in proliferation of human cultivated fibroblasts,
utilizing clinical doses. Human fibroblasts were synchronized in G0
stage, and irradiated with continuous wave of a 650 nm low-level laser
at doses of 0.5, 1, 3, 5 and 7 J/cm2, with power density of 30 mW/cm2.
Fibroblast proliferation was measured with a [3H]-tymidine incorporation
method. The results were measured at 24, 48, 72 and 96 hours. Fibroblast
proliferation showed no statistical differences between controls,
but it was observed some structure changes. It is probably that clinical
doses are not appropriated for culture stimulation, or maybe, it is
needed another power density.
Transmeatal cochlear
laser (TCL) treatment of cochlear dysfunction: a feasibility study
for chronic tinnitus. Lasers in Medical Science. 2003, 18
(3): 154-161.
Tauber S, Schorn K, Beyer W, Baumgartner R.
Low-level-laser-therapy (LLLT) targeting the inner ear has been discussed
as a therapeutic procedure for cochlear dysfunction such as chronic
cochlear tinnitus or sensorineural hearing loss. Former studies demonstrate
dose-dependent biological and physiological effects of LLLT such as
enhanced recovery of peripheral nerve injuries, which could be of
therapeutic interest in cochlear dysfunction. To date, in patients
with chronic tinnitus mastoidal and transmeatal irradiation has been
performed without systematic dosimetric assessment. However, light-dosimetric
studies on human temporal bones demonstrated that controlled application
of laserlight to the human cochlea depends on defined radiator position
within the external auditory meatus. This feasibility study first
presents a laser application system enabling dose-controlled transmeatal
cochlear laser-irradiation (TCL), as well as preliminary clinical
results in patients with chronic cochlear tinnitus. The novel laser
TCL-system, consisting of four diode lasers (lambda=635 nm-830 nm)
and a new specific head-set applicator, was developed on the basis
of dosimetric data from a former light-dosimetric study. In a preliminary
clinical study, the TCL-system was applied to 35 patients with chronic
tinnitus and sensorineural hearing loss. The chronic symptoms persisted
after standard therapeutic procedures for at least six months, while
retrocochlear or middle-ear pathologies have been ruled out. The patients
were randomised and received five single diode laser treatments (lambda=635
nm, 7.8 mW cw, n=17 and lambda=830 nm, 20 mW cw, n=18) with a space
irradiation of 4 J/cm2 site of maximal cochlear injury. For evaluation
of laser-induced effects complete otolaryngologic examinations with
audiometry, tinnitus masking and matching, and a tinnitus-self-assessment
were performed before, during and after the laser-irradiation. The
first clinical use of the TCL-system has been well tolerated without
side-effects and produced no observable damage to the external, middle
or inner ear. Changes of tinnitus loudness and tinnitus matching have
been described. After a follow-up period of six months tinnitus loudness
was attenuated in 13 of 35 irradiated patients, while two of 35 patients
reported their tinnitus as totally absent.
Effects of Low-level Laser Therapy in HIV/AIDS-positive
Patients After Exodontic Procedures.
Journal of Oral Laser Applications. 2003; 3 (2): 109-115.
Giovanni E M, Ferreira M C D, Souza R S et al.
The purpose of this study was to verify the efficiency of the GaAlAs
laser in the stimulation of tissue repair and analgesic effect after
tooth extractions in HIV/AIDS-positive patients. A low-level (790
nm, 30 mw) laser was applied in 15 HIV/AIDS-positive patients who
required extractions totalling 36 teeth. Platelet count, T-CD4 lymphocytes,
and the viral load of each patient were examined. After extraction
and suturing, the low-potency laser beam was applied to the surgical
area parallel to the long axis of the alveolus for a period of 2 min.
All the patients were instructed not to use any medications or supplementary
treatments. The postoperative exam was performed 8 days after surgery,
including the suture removal, periapical radiograph, area wound healing
evaluation, and a questionnaire to evaluate postoperative pain. The
patients generally reported a comfortable postoperative period. If
pain was present, it was very slight and required no medication or
other therapy. The process of tissue regeneration and surgical wound
healing took less time than with conventional procedures. Although
the patients presented various degrees of immune suppression as measured
by the T-CD4 lymphocyte count, and some had a high viral load, all
responded satisfactorily in the postoperative period.
Role of Gallium Arsenide Laser Irradiation at 890 nm as an
Adjunctive to Anti-tuberculosis
Drugs in the Treatment of Pulmonary Tuberculosis
Indian J Chest Dis Allied Sci. 2003; 45: 13 – 19.
M.M. Puri and V.K. Arora
The present study was carried out to explore whether any benefit could
be achieved by the addition of low level energy laser therapy (LLLT)
to the conventional anti-tubercular chemotherapy. One-hundred-thirty
new sputum smear positive patients of pulmonary tuberculosis were
enrolled to evaluate the bio-stimulatory effects of Gallium Arsenide
laser irradiation at 890 nm, as an adjuvant therapy. These patients
were randomly divided into two groups to receive either LLLT or sham
irradiation (control) concomitantly with anti-tuberculosis chemotherapy.
The patients treated with semiconductor laser as an adjuvant therapy
along with anti-tuberculosis drugs had a faster clearance of tubercle
bacilli from the sputum as compared to the control group (P value
at : 45 days=0.1392, 60 days=0.0117, 75 days=0.00805, 90 days=0.00739).
These findings provide preliminary evidence that low level laser therapy
with Gallium Arsenide laser may be a promising adjunctive therapy
for patients with tuberculosis. Faster conversion of sputum should
prevent the development of resistant mutants.
Usefulness of Low-Level Laser for Control
of Painful Stomatitis in Patients with Hand-Foot-and-Mouth Disease.
Journal of Clinical Laser Medicine & Surgery. 21 (6): 363–367.
Toida M; Watanabe F; Kazumi Goto K; Shibata T.
The aim of this study was to evaluate the usefulness of low-level
laser therapy (LLLT) for the control of painful stomatitis in patients
with hand-foot-and-mouth disease (HFMD). Through a randomized double-blind
placebo controlled trial, the painful period of HFMD stomatitis was
compared between the LLLT group (n = 11) and the placebo LLLT one
(n = 9), which had similar clinical backgrounds. The LLLT parameters
supplied were as follows: wavelength of 830 nm, power of 30 mW, frequency
of 30 Hz, and energy output of 1.1 J/cm2. Acceptability and safety
of the treatment were also evaluated. The painful period was shorter
in the LLLT group (4.0 ± 1.3 days) than in the placebo LLLT
one (6.7 ± 1.6 days) with a statistically significant difference
(p < 0.005). The treatment was judged acceptable for 90.0% (18
of 20) of patients. No adverse events were observed in any cases:
Low-Intensity Near-Infrared Laser Radiation-Induced Changes
of Acetylcholinesterase Activity
of Human Erythrocytes.
Journal of Clinical Laser Medicine & Surgery. 21 (6):351–355.
Kujawa J; Zavodnik L; Zavodnik I.
Suspensions of human erythrocytes in PBS (10% hematocrit) were irradiated
with near-infrared (810 nm) therapy laser at different light doses
(0-20 J) and light power (fluence rate; 200 or 400 mW) at 37°C.
As the parameters characterizing the cell structural and functional
changes membrane acetylcholinesterase (AchEase) activity, the membrane
potential, the level of intracellular glutathione, the level of products
of membrane lipid peroxidation, and the cell osmotic stability were
measured. It was found that near-infrared low-intensity laser radiation
produced complex biphasic dose-dependent changes of the parameters
of AchEase reaction in the dose-dependent manner: at smaller doses
of radiation (6 J) the maximal reaction rate and Michaelis-Menten
constant value decreased, and at higher radiation doses these parameters
increased. No significant changes of erythrocyte stability, cellular
redox state (reduced glutathione or lipid peroxidation product levels),
or cell membrane electrochemical potential were observed. Low-intensity
near-infrared laser radiation (810 mn) produced AchEase activity changes,
reflecting the effect of light on the enzyme due to energy absorption.
Protein molecule conformational transitions and enzyme activity modifications
in cells have been suggested as laser radiation-induced events.
Effect of 830-nm Laser Light on the Repair of Bone Defects
Grafted with Inorganic Bovine Bone and Decalcified Cortical
Osseous Membrane.
Journal of Clinical Laser Medicine & Surgery. 21 (6): 383–388.
Pinheiro A; De Assis Limeira Júnior F, Márquez Gerbi
M E.
The aim of this study was to assess histologically the effect of LLLT
(?830 nm) on the repair of standardized bone defects on the femur
of Wistar albinus rats grafted with inorganic bovine bone and associated
or not to decalcified bovine cortical bone membrane. Bone loss may
be a result of several pathologies, trauma or a consequence of surgical
procedures. This led to extensive studies on the process of bone repair
and development of techniques for the correction of bone defects,
including the use of several types of grafts, membranes and the association
of both techniques. There is evidence in the literature of the positive
effect of LLLT on the healing of soft tissue wounds. However, its
effect on bone is not completely understood. Five randomized groups
were studied: Group I (Control); Group IIA (Gen-ox®); Group IIB
(Gen-ox® + LLLT); Group IIIA (Gen-ox® + Gen-derm®) and
Group IIIB (Gen-ox® + Gen-derm® + LLLT). Bone defects were
created at the femur of the animals and were treated according to
the group. The animals of the irradiated groups were irradiated every
48 h during 15 days; the first irradiation was performed immediately
after the surgical procedure. The animals were irradiated transcutaneously
in four points around the defect. At each point a dose of 4 J/cm2
was given ( ~ 0.6 mm, 40 mW) and the total dose per session was 16
J/cm2. The animals were humanely killed 15, 21, and 30 days after
surgery. The specimens were routinely processed to wax, serially cut,
and stained with H&E and Picrosirius stains and analyzed under
light microscopy. The results showed evidence of a more advanced repair
on the irradiated groups when compared to non-irradiated ones. The
repair of irradiated groups was characterized by both increased bone
formation and amount of collagen fibers around the graft within the
cavity since the 15th day after surgery, through analysis of the osteoconductive
capacity of the Gen-ox® and the increment of the cortical repair
in specimens with Gen-derm® membrane. It is concluded that LLLT
had a positive effect on the repair of bone defect submitted the implantation
of graft.
Low Level Laser Therapy-a conservative approach to the burn
scar?
Burns. 2004 30(4):362-367.
Gaida K, Koller R, Isler C, Aytekin O et al.
Burn scars are known to be difficult to treat because of their tendency
to worsen with hypertrophy and contracture. Various experimental and
clinical efforts have been made to alleviate their effects but the
problem has not been solved. Since patients keep asking for Low Level
Laser Therapy (LLLT) and believe in its effectiveness on burn scars,
and since former studies show contradictory results of the influence
of LLLT on wound healing, this prospective study was designed to objectify
the effects of LLLT on burn scars. Nineteen patients with 19 burn
scars were treated with a 400mW 670nm Softlaser twice a week over
8 weeks. In each patient a control area was defined, that was not
irradiated. Parameters assessed were the Vancouver Scar Scale (VSS)
for macroscopic evaluation and the Visual Analogue Scale (VAS) for
pruritus and pain. Photographical and clinical assessments were recorded
in all the patients. Seventeen out of 19 scars exhibited an improvement
after treatment. The average rating on the VSS decreased from [Formula:
see text] to [Formula: see text] points in the treated areas, whereas
the VSS in the control areas decreased from [Formula: see text] to
[Formula: see text]. A correlation between scar duration and improvement
through LLLT could be found. No negative effects of LLLT were reported.
The present study shows that the 400mW 670nm softlaser has a positive,
yet sometimes limited effect on burn scars concerning macroscopic
appearance, pruritus, and pain.
Low-level laser therapy stimulates bone-implant
interaction: an experimental study in rabbits.
Clin Oral Implants Res. 2004; 15 (3): 325-332.
Khadra M, Ronold H J, Lyngstadaas S P, Ellingsen J E, Haanaes H R.
This study was performed as an animal trial of 8 weeks duration with
a blinded, placebo-controlled design. Two coin-shaped titanium implants
with a diameter of 6.25 mm and a height of 1.95 mm were implanted
into cortical bone in each proximal tibia of twelve New Zealand white
female rabbits (n=48). The animals were randomly divided into irradiated
and control groups. The LLLT was used immediately after surgery and
carried out daily for 10 consecutive days. The animals were killed
after 8 weeks of healing. The mechanical strength of the attachment
between the bone and 44 titanium implants was evaluated using a tensile
pullout test. Histomorphometrical analysis of the four implants left
in place from four rabbits was then performed. Energy-dispersive X-ray
microanalysis was applied for analyses of calcium and phosphorus on
the implant test surface after the tensile test. The mean tensile
forces, measured in Newton, of the irradiated implants and controls
were 14.35 (SD+/-4.98) and 10.27 (SD+/-4.38), respectively, suggesting
a gain in functional attachment at 8 weeks following LLLT (P=0.013).
The histomorphometrical evaluation suggested that the irradiated group
had more bone-to-implant contact than the controls. The weight percentages
of calcium and phosphorus were significantly higher in the irradiated
group when compared to the controls (P=0.037) and (P=0.034), respectively,
suggesting that bone maturation processed faster in irradiated bone.
These findings suggest that LLLT might have a favourable effect on
healing and attachment of titanium implants.
Dose and Wavelength of Laser Light Have Influence on the Repair
of Cutaneous Wounds.
Journal of Clinical Laser Medicine & Surgery. 2004; 22 (1):19-25.
Mendez T; Pinheiro A; Pacheco M; Nascimento P;Ramalho L.
The objective of the present study was to compare histologically the
effect of GaAlAs (? 830 nm, ~ 2 mm2, 35 mW) and InGaAlP (? 685 nm,
~ 2 mm2, 35 mW) lasers, alone or in association with doses of 20 or
50 J/cm2 on cutaneous wounds in the dorsum of the Wistar rat. The
healing time of surgical wounds is of extreme importance and it is
usually associated with a post-operative period free of infection
and with less pain and inflammation. Sixty Wistar rats were divided
into seven groups: Group I - control (non-irradiated); Group II -
? 685 nm, 20 J/cm2; Group III - ? 830 nm, 20 J/cm2; Group IV - ? 685
nm and ? 830 nm, 20 J/cm2; Group V - ? 685 nm, 50 J/cm2); Group VI
- ? 830 nm, 50 J/cm2; and Group VII - ? 685 nm and 830 nm, 50 J/cm2.
The animals were sacrificed 3, 5, and 7 days after surgery. Light
microscopic analysis using H&E and Picrosírius stains showed
that, at the end of the experimental period, irradiated subjects showed
increased collagen production and organization when compared to non-irradiated
controls. Inflammation was still present in all groups at this time.
Group IV (? 830 nm and ? 685 nm, 20 J/cm2) presented better results
at the end of the experimental period. It is concluded that low-level
light therapy (LLLT) can have a positive biomodulatory effect on the
repair of cutaneous wounds.
Polychromatic LED Therapy in Burn
Healing of Non-diabetic and Diabetic Rats
Author(s): Farouk A. H. Al-Watban MSc, PhD ; Bernard L. Andres RMT,
MT(AMT)
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 5 Page: 249 -- 258
DOI: 10.1089/104454703322564451
Abstract: Objective: We determined the effect of polychromatic light-emitting
diodes (LED) in burn healing of non-diabetic and streptozotocin-induced
diabetic rats. Background Data: LEDs were used as the light source
for phototherapy. Materials and Methods: The polychromatic LED is
a cluster of 25 diodes emitting photons at wavelengths of 510-543,
594-599, 626-639, 640-670, and 842-879 nm with 272-mW output power.
Age-matched, male Sprague-Dawley rats (n = 30) were used. Streptozotocin
(70 mg/kg) was used for diabetes induction. Rat weight, hyperglycemia,
and glycosuria were monitored for the first 3 days and weekly thereafter.
Rats were anesthetized and shaved after 1 week of diabetes. Burn areas
of 1.5 ± .03 cm2 were created using a metal rod pre-heated
up to 600°C that was applied for 2 sec. Diabetic and non-diabetic
rats were randomized into the following treatment groups: control,
5, 10, 20, and 30 J/cm2. Light treatment commenced after burn infliction
and was repeated three times per week. Burn areas were measured daily.
Results: Burn healing was impaired significantly during diabetes by
-46.17%. Polychromatic LED treatment using 5, 10, 20, and 30 J/cm2
incident doses influenced healing by 6.85%, 4.93%, -4.18%, and -5.42%
in the non-diabetic rats; and 73.87%, 76.77%, 60.92%, and 48.77% in
the diabetic rats, relative to their controls, respectively. Conclusion:
The effect of polychromatic LED in non-diabetic rats was insignificant;
however, it simulated the trend of stimulation and inhibition seen
using low-level lasers. Significant stimulation observed in the diabetic
rats demonstrated the usefulness of polychromatic LED in diabetic
burn healing.
Effects of Pulse Frequency of Low-Level Laser Therapy (LLLT)
on Bone Nodule Formation in Rat Calvarial
Cells
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 5 Page: 271 -- 277
DOI: 10.1089/104454703322564479
Author(s): Yuji Ueda ; Noriyoshi Shimizu
Abstract: Objective: The purpose of this study was to determine the
effect of pulse frequencies of low-level laser therapy (LLLT) on bone
nodule formation in rat calvarial cells in vitro. Background Data:
Various photo-biostimulatory effects of LLLT, including bone formation,
were affected by some irradiation factors such as total energy dose,
irradiation phase, laser spectrum, and power density. However, the
effects of pulse frequencies used during laser irradiation on bone
formation have not been elucidated. Materials and Methods: Osteoblast-like
cells isolated from fetal rat calvariae were irradiated once with
a low-energy Ga-Al-As laser (830 nm, 500 mW, 0.48-3.84 J/cm2) in four
different irradiation modes: continuous irradiation (CI), and 1-,
2-, and 8-Hz pulsed irradiation (PI-1, PI-2, PI-8). We then investigated
the effects on cellular proliferation, bone nodule formation, alkaline
phosphatase (ALP) activity, and ALP gene expression. Results: Laser
irradiation in all four groups significantly stimulated cellular proliferation,
bone nodule formation, ALP activity, and ALP gene expression, as compared
with the non-irradiation group. Notably, PI-1 and -2 irradiation markedly
stimulated these factors, when compared with the CI and PI-8 groups,
and PI-2 irradiation was the best approach for bone nodule formation
in the present experimental conditions. Conclusion: Since low-frequency
pulsed laser irradiation significantly stimulates bone formation in
vitro, it is most likely that the pulse frequency of LLLT an important
factor affecting biological responses in bone formation.
Effects of Low-Level Laser Therapy (LLLT) of 810 nm upon
in Vitro Growth of Bacteria: Relevance of Irradiance
and Radiant Exposure
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 5 Page: 283 -- 290
DOI: 10.1089/104454703322564497
Author(s): Ethne L. Nussbaum PhD, MEd, BScPT ; Lothar Lilge PhD ;
Tony Mazzulli MD, FRCPC
Abstract: Objective: The aim of this study was to investigate the
irradiance-dependency of low-level laser therapy (LLLT) effects on
bacterial growth. Background: LLLT is applied to open wounds to improve
healing; however, its effect on wound bacteria is not well understood.
Materials and Methods: Escherichia coli, Pseudomonas aeruginosa, and
Staphylococcus aureus were irradiated using a wavelength of 810 nm
at irradiances of 0.015 W/cm2 (0-50 J/cm2) and 0.03 W/cm2 (0-80 J/cm2).
Bacteria were counted after 20 h of incubation. Results: LLLT effects
varied significantly with species. P.aeruginosa growth decreased overall
dependent on an interaction of irradiance and radiant exposure; greatest
inhibition was produced using high irradiance delivering radiant exposures
in the range of 1-20 J/cm2 (p = 0.001-0.04). In contrast, E. coli
growth increased overall (p = 0.01), regardless of irradiance; greatest
effects were produced using low radiant exposures (1-20 J/cm2). There
was a main effect for irradiance (p = 0.03) on S. aureus growth; however,
growth was not different compared with controls. Additional analysis
showed that there were differences in growth of P.aeruginosa when
comparing samples that were matched by exposure times (66, 329, 658,
1316, 1974, and 2632 sec) rather than radiant exposure; this suggests
that irradiance rather than exposure time was the significant factor
in P. aeruginosa inhibition. Conclusion: These findings have immediate
relevancy in the use of LLLT for infected wounds. Exposure to 810-nm
irradiation (0.03 W/cm2) could potentially benefit wounds infected
with P. aeruginosa. However, increased E. coli growth could further
delay recovery.
Effect of the Clinical Application
of the GaAlAs Laser in the Treatment of Dentine Hypersensitivity
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 5 Page: 291 -- 296
DOI: 10.1089/104454703322564505
Author(s): Ana Lucia Marsilio DDS, MS, PhD ; José Roberto Rodrigues
DDS, MS, PhD ; Alessandra Bühler Borges DDS, MS, PhD
Abstract: Objective: The aim of this study was to evaluate the effectiveness
of the clinical use of the gallium-aluminum-arsenium (GaAlAs) laser
at the maximum and minimum energies recommended by the manufacturer
for the treatment of dentine hypersensitivity. Background Data: Dentine
hypersensitivity (DH) is a response to a stimulus that would not usually
cause pain in a healthy tooth. It is characterized by sharp pain of
short duration from the denuded dentin. Its etiology is unknown. The
dentin only begins to show sensitivity when exposed to the buccal
environment. This exposure can result after removal of the enamel
and/or dental cement, or after root denudation. Different treatments
are proposed for this disorder. Materials and Methods: In this study,
25 patients, with a total number of 106 cases of DH, were treated
with GaAlAs low-level laser therapy (LLLT). 65% of the teeth were
premolars; 14% were incisors and molars; 6.6% were canines. The teeth
were irradiated with 3 and 5 J/cm2 for up to six sessions, with an
interval of 72 h between each application, and they were evaluated
initially, after each application, and at 15 and 60 days follow-up
post-treatment. Results: The treatment was effective in 86.53% and
88.88% of the irradiated teeth, respectively, with the minimum and
maximum energy recommended by the manufacturer. There was a statistically
significant difference between DH and after a follow-up of 60 days
for both groups. The difference among the energy maximum and minimum
was not significant. Conclusion: The GaAlAs low-level laser was effective
in reducing initial DH. A significant difference was found between
initial values of hypersensitivity and after 60 days follow-up post-treatment.
No significant difference was found between minimum (3 J/cm2) and
maximum (5 J/cm2) applied energy.
Effect of Low-Power Radiation (Helium/Neon) upon Submandibulary
Glands
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 4 Page: 219 -- 225
DOI: 10.1089/104454703768247792
Author(s): Luis M. Plavnik DDM ; Marta E. De Crosa DDM ; Alicia I.
Malberti PhD
Abstract: Objective: The aim of this work was to study the effect
of low-power laser radiation on guinea pig salivary glands. Background
Data: Low-power laser radiation changes some cellular functions. The
effect on salivary glands has not been sufficiently studied. Materials
and Methods: One hundred and forty-four male guinea pigs (150 ±
30 g body weight) were used. The animals were divided into two groups:
control group (fed animals and those undergoing 2, 4, 8, 10, and 12
h of fasting) and experimental group (irradiated). Both the right
and left submandibular glands were later irradiated with helium-neon
laser at 7-mW power, with a 0.75-mm spot, under continuous pulse for
2 min in a one-session exposure; a 11.2 J/cm2 energy density was applied.
Then, the irradiated animals were fed, or underwent 2, 4, 8, 10 and
12 h of fasting. Samples of submandibular glands were taken with a
punch (5 mm diameter) and were used for optic and transmission electron
microscopy studies. Results: The structural observations showed that
the irradiation effect was progressive; and showed a trophic stimulant
effect at 2 h following irradiation, with vasodilatation, vascular
congestion, perivascular infiltrate, and a necrotic picture of glandular
parenchyma at longer times. The ultrastructural observations showed
alterations of rough endoplasmic reticulum. Conclusion: We propose
that low-power laser radiation with the doses applied in this study
disturbs protein synthesis and secretion of guinea pig submandibulary
glands.
Low-Level Laser Irradiation Attenuates Production
of Reactive Oxygen Species by Human Neutrophils
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 3 Page: 165 -- 170
DOI: 10.1089/104454703321895635
Author(s): Yuji Fujimaki MD ; Tadashi Shimoyama PhD ; Qiang Liu PhD
; Takashi Umeda PhD ; Shigeyuki Nakaji PhD ; Kazuo Sugawara PhD
Abstract: Objective: The aim of this study was to examine the effects
of low-level laser therapy (LLLT) on production of reactive oxygen
(ROS) species by human neutrophils. Background Data: LLLT is an effective
therapeutic modality for inflammatory conditions. Materials and Methods:
The laser device used was the infrared diode laser (GaAlAs), 830-nm
continuous wave (150 mW/cm2). After irradiation, ROS production by
neutrophils was measured using luminol-dependent chemiluminescence
(LmCL) and expression of CD11b and CD16 on neutrophil surface was
measured by flow cytometry. Results: The LmCL response of neutrophils
was reduced by laser irradiation at 60 min prior to the stimulation
with opsonized zymosan and calcium ionophore. The attenuating effect
of LLLT was larger in neutrophils of smokers than non-smokers, while
the amount of produced ROS was larger in neutrophils of smokers. Expression
of CD11b and CD16 on neutrophil surface was not affected by LLLT.
Conclusion: Attenuation of ROS production by neutrophils may play
a role in the effects of LLLT in the treatment of inflammatory tissues.
There is a possible usage of LLLT to improve wound healing in smokers.
Effect of NASA Light-Emitting Diode Irradiation
on Molecular Changes for Wound Healing in Diabetic Mice
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 2 Page: 67 -- 74
DOI: 10.1089/104454703765035484
Author(s): Harry T. Whelan MD ; Ellen V. Buchmann BS ; Apsara Dhokalia
PhD ; Mary P. Kane BS ; Noel T. Whelan BS ; Margaret T.T. Wong-Riley
PhD ; Janis T. Eells PhD ; Lisa J. Gould MD, PhD ; Rasha Hammamieh
PhD ; Rina Das PhD ; Marti Jett PhD
Abstract: Objective: The purpose of this study was to assess the changes
in gene expression of near-infrared light therapy in a model of impaired
wound healing. Background Data: Light-Emitting Diodes (LED), originally
developed for NASA plant growth experiments in space, show promise
for delivering light deep into tissues of the body to promote wound
healing and human tissue growth. In this paper we present the effects
of LED treatment on wounds in a genetically diabetic mouse model.
Materials and Methods: Polyvinyl acetal (PVA) sponges were subcutaneously
implanted in the dorsum of BKS.Cg-m +/+ Leprdb mice. LED treatments
were given once daily, and at the sacrifice day, the sponges, incision
line and skin over the sponges were harvested and used for RNA extraction.
The RNA was subsequently analyzed by cDNA array. Results: Our studies
have revealed certain tissue regenerating genes that were significantly
upregulated upon LED treatment when compared to the untreated sample.
Integrins, laminin, gap junction proteins, and kinesin superfamily
motor proteins are some of the genes involved during regeneration
process. These are some of the genes that were identified upon gene
array experiments with RNA isolated from sponges from the wound site
in mouse with LED treatment. Conclusion: We believe that the use of
NASA light-emitting diodes (LED) for light therapy will greatly enhance
the natural wound healing process, and more quickly return the patient
to a preinjury/illness level of activity. This work is supported and
managed through the Defense Advanced Research Projects Agency (DARPA)
and NASA Marshall Space Flight Center-SBIR Program.
Influence of Linearly Polarized Near-Infrared Irradiation
on Deformability of Human Stored Erythrocytes
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21
Number: 1 Page: 19 -- 22
DOI: 10.1089/10445470360516699
Author(s): Kozo Yokoyama DDS, PhD ; Kazuna Sugiyama DDS, PhD
Abstract: Objective: To investigate the influence of linearly polarized
near-infrared irradiation using the Super Lizer™ on deformability
of human erythrocytes. Background Data: Not only low-powered laser
but also linearly polarized near-infrared beams have some biostimulation
effects on various tissues. There were some reports of erythrocyte
deformability improved by low-powered He-Ne laser irradiation. Materials
and Methods: Human erythrocyte samples stored for three weeks were
adjusted to 30% hematocrit. Erythrocyte deformability presented as
the filter filtration rate was measured. Results: There was no difference
of the filter filtration rate between control group without irradiation
and the group of 125 mJ/cm2 exposure level at a wavelength of 830
nm. However, the groups of 625 and 1,250 mJ/cm2 exposure levels at
a wavelength of 830 nm showed higher filter filtration rates compared
to the control group. Conclusion: Linearly polarized near-infrared
irradiation in a range of 625-1,250 mJ/cm2 exposure level at a wavelength
of 830 nm improved deformability of human stored erythrocytes.
The Comparison of Effects between Pulsed and CW Lasers
on Wound Healing
Source: Journal of Clinical Laser Medicine & Surgery Volume: 22
Number: 1 Page: 15 -- 18
DOI: 10.1089/104454704773660921
Author(s): Farouk A.H. Al-Watban MSc, PhD ; X.Y. Zhang MD
Abstract: Objective: In order to evaluate the effects of pulsed continuous
wave (CW) laser and detect the role of wound healing in rats using
both pulsed and CW 635-nm low-level laser therapy (LLLT), a pilot
study was undertaken. Background Data: Some acceleration effects of
wound healing on animals were found after treatment using various
lasers with CW. There are other reports, however, using pulsed CW
laser to evaluate the effects of wound healing in rats. Materials
and Methods: An elliptic wound was created aseptically with a scalpel
on the shaved back of the rats after anesthesia. The rats treated
were restrained in a Plexiglas cage without anesthesia during the
laser irradiation period. An Erchonia pulse laser (635 nm) was used
in the experiment. The laser beam was delivered through an expander.
The percentage of relative wound healing was calculated. Results:
The percentage of relative wound healing was 4.32 in 100 Hz, 3.21
in 200 Hz, 3.83 in 300 Hz, 2.22 in 400 Hz, 1.73 in 500 Hz and 4.81
in CW. Conclusion: LLLT using pulsed, CW laser at the appropriate
dosimetry and frequency can provide acceleration in wound healing
in rats. The 100-Hz frequency had a better effect than other pulse
frequencies used in the study. The effects of treatment using CW laser
was higher than pulse frequency. The frequency of pulsed CW laser
was not found to increase wound healing in rats compared with normal
CW laser, as reported in our previous studies
NASA Light-Emitting Diodes for the Prevention of Oral Mucositis
in Pediatric Bone Marrow Transplant Patients
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20
Number: 6 Page: 319 -- 324
DOI: 10.1089/104454702320901107
Author(s): Harry T. Whelan MD ; James F. Connelly MD ; Brian D. Hodgson
DDS ; Lori Barbeau DDS ; A. Charles Post DDS ; George Bullard DDS
; Ellen V. Buchmann BS ; Mary Kane BS ; Noel T. Whelan BS ; Ann Warwick
MD ; David Margolis MD
Abstract: Objective: The purpose of this study was to determine the
effects of prophylactic near-infrared light therapy from light-emitting
diodes (LEDs) in pediatric bone marrow transplant (BMT) recipients.
Background Data: Oral mucositis (OM) is a frequent side effect of
chemotherapy that leads to increased morbidity. Near-infrared light
has been shown to produce biostimulatory effects in tissues, and previous
results using near-infrared lasers have shown improvement in OM indices.
However, LEDs may hold greater potential for clinical applications.
Materials and Methods: We recruited 32 consecutive pediatric patients
undergoing myeloablative therapy in preparation for BMT. Patients
were examined by two of three pediatric dentists trained in assessing
the Schubert oral mucositis index (OMI) for left and right buccal
and lateral tongue mucosal surfaces, while the patients were asked
to rate their current left and right mouth pain, left and right xerostomia,
and throat pain. LED therapy consisted of daily treatment at a fluence
of 4 J/cm2 using a 670-nm LED array held to the left extraoral epithelium
starting on the day of transplant, with a concurrent sham treatment
on the right. Patients were assessed before BMT and every 2-3 days
through posttransplant day 14. Outcomes included the percentage of
patients with ulcerative oral mucositis (UOM) compared to historical
epidemiological controls, the comparison of left and right buccal
pain to throat pain, and the comparison between sides of the buccal
and lateral tongue OMI and buccal pain. Results: The incidence of
UOM was 53%, compared to an expected rate of 70-90%. There was also
a 48% and 39% reduction of treated left and right buccal pain, respectively,
compared to untreated throat pain at about posttransplant day 7 (p
< 0.05). There were no significant differences between sides in
OMI or pain. Conclusion: Although more studies are needed, LED therapy
appears useful in the prevention of OM in pediatric BMT patients.
Effects of 630-, 660-, 810-, and 905-nm Laser Irradiation
Delivering Radiant Exposure of 1-50
J/cm2 on Three Species of Bacteria in Vitro
Author(s): Ethne L. Nussbaum MEd, PhD ; Lothar Lilge PhD ; Tony Mazzulli
MD, FRCPC
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20
Number: 6 Page: 325 -- 333
DOI: 10.1089/104454702320901116
Abstract: Objective: To examine the effects of low-intensity laser
therapy (LILT) on bacterial growth in vitro. Background Data: LILT
is undergoing investigation as a treatment for accelerating healing
of open wounds. The potential of coincident effects on wound bacteria
has received little attention. Increased bacterial proliferation could
further delay recovery; conversely inhibition could be beneficial.
Materials and Methods: Pseudomonas aeruginosa, Escherichia coli, and
Staphylococcus aureus were plated on agar and then irradiated with
wavelengths of 630, 660, 810, and 905 nm (0.015 W/cm2) and radiant
exposures of 1-50 J/cm2. In addition, E. coli was irradiated with
810 nm at an irradiance of 0.03 W/cm2 (1-50 J/cm2). Cells were counted
after 20 h of incubation post LILT. Repeated measures ANOVA and Tukey
adjusted post hoc tests were used for analysis. Results: There were
interactions between wavelength and species (p = 0.0001) and between
wavelength and radiant exposure (p = 0.007) in the overall effects
on bacterial growth; therefore, individual wavelengths were analyzed.
Over all types of bacteria, there were overall growth effects using
810- and 630-nm lasers, with species differences at 630 nm. Effects
occurred at low radiant exposures (1-20 J/cm2). Overall effects were
marginal using 660 nm and negative at 905 nm. Inhibition of P. aeruginosa
followed irradiation using 810 nm at 5 J/cm2 (-23%; p = 0.02). Irradiation
using 630 nm at 1 J/cm2 inhibited P. aeruginosa and E. coli (-27%).
Irradiation using 810 nm (0.015 W/cm2) increased E. coli growth, but
with increased irradiance (0.03 W/cm2) the growth was significant
(p = 0.04), reaching 30% at 20 J/cm2 (p = 0.01). S. aureus growth
increased 27% following 905-nm irradiation at 50 J/cm2. Conclusion:
LILT applied to wounds, delivering commonly used wavelengths and radiant
exposures in the range of 1-20 J/cm2, could produce changes in bacterial
growth of considerable importance for wound healing. A wavelength
of 630 nm appeared to be most commonly associated with bacterial inhibition.
The findings of this study might be useful as a basis for selecting
LILT for infected wounds.
Contraindications in Noninvasive
Laser Therapy: Truth and Fiction
Author(s): Leos Navratil MD, PhD ; Jaroslava Kymplova MD, PhD
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20
Number: 6 Page: 341 -- 343
DOI: 10.1089/104454702320901134
Abstract: Objective: Noninvasive laser therapy is a treatment method
employed in many disciplines. This review article points out instances
when it appears to be effective to administer such therapy. Materials
and Methods: Noninvasive laser therapy has a number of suitable applications
that cause minimal damage to the patient. Many patients are not sent
to institutions equipped with relevant instruments, since physicians
are burdened by a number of contraindications, many of which are incorrect.
The purpose of this article was to divide these contraindications
into the following three groups: correct indications, indications
doubtful under certain conditions, and incorrect indications. Discussion:
We consider the following contraindications as correct: history of
a histologically demonstrated malignant carcinoma; irradiation of
the neck region in hyperthyreosis; epilepsy; exposure of the retina;
and exposure of the abdomen during pregnancy. The contraindications
that are doubtful under certain conditions are as follows: fever and
infectious diseases; certain blood diseases; heavy blood losses; neuropathies;
and irradiation in the region of gonads. The other contraindications
reported in the literature are considered to be incorrect.
Low-Intensity Laser Therapy/Combined Phototherapy in the Management
of Chronic Venous Ulceration: A Placebo-Controlled Study
Author(s): Katie M. Lagan DPhil ; Toni McKenna BSc ; Anne Witherow
RGN, PgDip(wound healing) ; Jean Johns BSc ; Suzanne M. McDonough
PhD ; G. David Baxter DPhil
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20
Number: 3 Page: 109 -- 116
DOI: 10.1089/104454702760090173
Abstract: Objective: The current placebo-controlled study was undertaken
to investigate the efficacy of combined phototherapy and low-intensity
laser therapy (LILT) in the management of chronic venous ulceration
when used in conjunction with standardized nursing intervention. Materials
and Methods: Approval was granted by Research Ethical Committees at
the University of Ulster and Altnagelvin Hospitals Health and Social
Services Trust. Patients (n = 15; 10 female/5 male; age ± SD
= 69.9 ± 13.8 years) were recruited from an outpatient "leg
ulcer clinic," where they attended once per week for irradiation/sham
treatments for 4 weeks. Treatment was withheld for a total of 8 weeks,
and patients were reviewed during this time (weeks 8 and 12) for ulcer
and pain assessment only. A multisource diode array (660-950 nm) was
used for irradiation; parameters were kept constant for the duration
of the study (532 mW; 5 kHz; 12 J/cm2). Wound and pain assessment
were carried out by an independent investigator. Digitizing was used
to quantify surface areas from wound tracings. Results: Although there
was no statistically significant difference between Treatment and
Placebo groups, an apparent clinical difference in wound healing rate
was noted; at postirradiation, a continued reduction in wound size
was evident for the treatment group. These effects were believed to
be due to an apparent delayed effect. There was no statistically significant
difference between groups for pain. Conclusion: These findings provide
only limited evidence for the use of this modality as an adjunctive
therapy with current nursing intervention. Further group studies are
indicated to investigate the apparent delayed effect reported here
for various etiologies of ulceration.
TI Therapeutic photobiomodulation for methanol-induced
retinal toxicity.
AU Eells-J-T, Henry-M-M, Summerfelt-P, Wong-Riley-M-T-T, Buchmann-E-V,
Kane-M, Whelan-N-T, Whelan-H-T.
IN J.T. Eells, Department of Pharmacology, Medical College of Wisconsin,
8701 Watertown Plank Road, Milwaukee, WI 53226, United States
e-mail: jeells@mcw.edu.
SO Proceedings of the National Academy of Sciences of the United States
of America {PROC-NATL-ACAD-SCI-U-S-A}, 18 MAR 2003, Vol/Iss/Pg. 100/6
(3439-3444), ISSN: 0027-8424.
AB Methanol intoxication produces toxic injury to the retina and optic
nerve, resulting in blindness. The toxic metabolite in methanol intoxication
is formic acid, a mitochondrial toxin known to inhibit
the essential mitochondrial enzyme, cytochrome oxidase. Photobiomodulation
by red to near-IR radiation has been demonstrated to enhance mitochondrial
activity and promote cell survival in vitro
by stimulation of cytochrome oxidase activity. The present studies
were undertaken to test the hypothesis that exposure to monochromatic
red radiation from light-emitting diode (LED) arrays would protect
the retina against the toxic actions of methanol-derived formic acid
in a rodent model of methanol toxicity. Using the electroretinogram
as a sensitive indicator of retinal function, we demonstrated that
three brief (2 min, 24 s) 670-nm LED treatments (4 J/cm(2)), delivered
at 5, 25, and 50 h of methanol intoxication, attenuated the retinotoxic
effects of methanol-derived formate. Our studies document a significant
recovery of rod- and cone-mediated function in LED-
treated, methanol-intoxicated rats. We further show that LED treatment
protected the retina from the histopathologic changes induced by methanol-derived
formate. These findings provide a link
between the actions of monochromatic red to near-IR light on mitochondrial
oxidative metabolism in vitro and retinoprotection in vivo. They also
suggest that photobiomodulation may enhance recovery from retinal
injury and other ocular diseases in which mitochondrial dysfunction
is postulated to play a role.
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