Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: tension; failure strain; fibroblasts; regenerative medicine; serum-free; proteoglycans; glycosaminoglycans; collagen; wound-healing model; cell-remodeled matrix; cell-derived matrix; biomechanical characterization; fibrin gel; growth factors; tissue growth; total protein content; tissue formation. Includes bibliographical references (p.44-53).

Thesis (Ph.D.)--Ohio University, November, 2006. / Includes bibliographical references (leaves 155-168).

Sensorless speed estimation in induction machines (IMs) presents an attractive proposition for eliminating the need for physical speed measurement sensors and thus avoiding the associated reliability and cost issues, such as the requirement of extra wiring, careful mounting, maintenance and adjustment. In this thesis, the feasibility of utilising the stator current and power signals to establish spectral search based (SSB) sensorless speed estimation schemes in wound rotor induction machines (WRIMs) operating in extended slip and open-loop controlled conditions is investigated. The research is performed on three different industrial WRIM designs. The thesis first investigates the spectral content of WRIM electrical and mechanical signals with the principal aim of identifying spectral patterns that can facilitate the development of real-time sensorless speed estimation. The examination is based on detailed harmonic models of the considered machine designs as well as experimental results obtained from tests performed on laboratory test rigs. A generalised theoretical analysis of the possible spectral content of machine signals that enables the derivation of closed form analytical expressions linking individual spectral frequencies to rotor speed is also undertaken. The results demonstrate that it is possible to clearly identify speed dependent components in the stator current and power signals and map the boundaries of the narrowbands maximised by these for extended slip and open-loop operating conditions. To enable improvement in attainable real time SSB estimation rates a dichotomous search algorithm real-time spectral processing method was employed for frequency tracking in this research. The algorithm performance is evaluated in real-time tests performed on a measured steady-state laboratory machine stator current and power signals. The results demonstrate that the dichotomous routine provides an inherent advantage in the frequency estimation rate without compromising the estimation accuracy and can therefore enable significant estimation rate improvement in SSB speed estimation algorithms. Novel sensorless speed SSB estimation techniques are then proposed for WRIM operation in extended slip and voltage/frequency controlled conditions. The algorithms utilise the reported analysis of electrical signals and are separately defined for each assessed operation mode and the stator current, phase power and three-phase power signals. It is shown that, in principle, power signal based estimation algorithms can offer an inherent capability of estimation rate reduction. A novel adaptive sliding window algorithm is defined for open-loop operating conditions that enable estimation in a wide operating speed range while minimising the potential for undesirable overlap with PWM harmonics. The proposed algorithms have been verified and their performance limitations assessed in real-time experiments on three different industrial WRIM designs. It is shown that reliable real-time speed estimation in steady-state and transient operating conditions is possible at an improved estimation rate while maintaining a low estimation error.

Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-23T13:47:41Z No. of bitstreams: 1 Tese - Ana Paula Cavalcanti.pdf: 9447670 bytes, checksum: 44f05935b4d040bdf7dacb56067b1fe3 (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-08T11:47:47Z (GMT) No. of bitstreams: 1 Tese - Ana Paula Cavalcanti.pdf: 9447670 bytes, checksum: 44f05935b4d040bdf7dacb56067b1fe3 (MD5) / Made available in DSpace on 2013-05-08T11:47:47Z (GMT). No. of bitstreams: 1 Tese - Ana Paula Cavalcanti.pdf: 9447670 bytes, checksum: 44f05935b4d040bdf7dacb56067b1fe3 (MD5) Previous issue date: 2008 / O objetivo do presente estudo foi avaliar histologicamente o reparo de feridas cutâneas em dorso de ratos submetidos ao tratamento com Laser e/ou LED, utilizando laser de diodo GaAlAs nos comprimentos de onda de λ660nm e λ790nm e LEDs em três comprimentos de onda. Foram utilizados 44 ratos da linhagem Wistar adultos jovens, machos, pesando entre 200 e 250 gramas. Após a realização de uma ferida excisional no dorso, os animais foram distribuídos aleatoriamente em onze grupos de estudo, com quatro animais cada: G0- Controle; G1- Laser λ660nm, 10J/cm2; G2- Laser λ790nm, 10J/cm2; G3- LED ~λ700nm, 15mW, 10J/cm2; G4- Laser λ660nm + LED ~λ700nm, 10J/cm2; G5- LED ~λ700nm, 16mW, 10J/cm2; G6- Laser λ790nm + LED ~λ700nm, 10J/cm2; G7- LED ~λ530nm, 10J/cm2; G7- Laser λ790nm + LED ~λ530nm, 10J/cm2; G8 - LED ~λ460nm, 10J/cm2; G10- Laser λ790nm + LED ~λ460nm, 10J/cm2. As irradiações foram realizadas durante sete dias com intervalos de 48 horas, e a morte animal ocorreu no oitavo dia. As peças foram removidas, processadas histologicamente e coradas com HE e Picrosírius, e analisadas por microscopia óptica. Os resultados indicam que as radiações laser λ790nm, LED vermelha (~λ700nm)(15mW) e as associações LED vermelho com laser λ790nm e LED verde com laser λ790nm apresentaram biomodulação positiva sobre a quantidade de fibroblastos e de fibras colágenas. A associação LED verde com laser λ790nm, dentre todos os tratamentos, resultou na deposição de colágeno mais significante e as radiações LED vermelha (15 e 16mW) e laser λ660nm exerceram o efeito de biomodulação positiva mais expressivo na proliferação de fibroblastos e na angiogênese. As radiações laser, LED e suas associações, dentro dos parâmetros especificados, exercem, de maneira geral, biomodulação positiva sobre a proliferação de fibroblastos, a formação de tecido de granulação, a deposição de fibras colágenas e a angiogênese. / Salvador

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Ãlcera por pressÃo (UP) à uma lesÃo comum entre idosos e indivÃduos com mobilidade fÃsica prejudicada. Ela afeta a qualidade de vida dos indivÃduos e gera custos considerÃveis, uma vez que està se tornando um problema mundial crescente, devido ao envelhecimento da populaÃÃo. Ciclos de isquemia e reperfusÃo tÃm sido identificados como fatores causais primÃrios, mas existem outros fatores que influenciam a intensidade dos danos. Atualmente, nÃo existe um mÃtodo eficaz e de baixo custo para tratar esta condiÃÃo. O uso clÃnico da fumaÃa de Artemisia vulgaris (FAV) para o tratamento de lesÃes na pele de diversas origens està descrito na literatura. Entretanto à pouco documentado e atualmente nada foi descrito em modelos experimentais de ulcera por pressÃo a respeito da sua atividade cicatrizante, bem como o seu efeito tÃxico. Dessa forma objetivou-se investigar o perfil toxicolÃgico e o efeito cicatrizante da aplicaÃÃo tÃpica da fumaÃa de Artemisia vulgaris em modelo de Ãlcera por pressÃo em camundongos. Este trabalho foi aprovado pelo Comità de Ãtica (89/2011). Foi utilizado um modelo nÃo-invasivo de UP em camundongos Swiss machos, que consiste em 4 ciclos de isquemia e reperfusÃo atravÃs da colocaÃÃo de dois ÃmÃs na superfÃcie da pele dorsal. Cinco grupos experimentais foram testados: (1): com Ãlcera e sem tratamento, (2): com Ãlcera e FAV tÃpico, (3): com Ãlcera, FAV tÃpica e filme de poliuretano, (4): com Ãlcera e tratado com hidrogel e filme de poliuretano e (5) sem Ãlcera, e sem tratamento. A anÃlise foi realizada nos dias 5, 7, 14 e 21 apÃs a induÃÃo da Ãlcera. Foram avaliados parÃmetros macroscÃpicos de cicatrizaÃÃo atravÃs da escala EWAT (Experimental Wound Assessment Tool â Instrumento de avaliaÃÃo de ferida experimental), Ãrea da ferida e porcentagem de contraÃÃo. Nos parÃmetros microscÃpicos foram avaliados: a anÃlise histopatolÃgica, a espessura da camada de colÃgeno e densidade de colÃgeno na derme, a contagem de fibroblastos e fibrÃcitos e a mediÃÃo da espessura da epiderme. AvaliaÃÃo da imunomarcaÃÃo para NOSi e nitrotirosina e ensaio de malondialdeÃdo (MDA) foi realizado para investigar o stress oxidativo. Testes toxicolÃgicos com parÃmetros hematolÃgicos, bioquÃmicos, histopatolÃgicos e comportamentais foram realizados em animais tratados com FAV. Resultados: a FAV nÃo mostrou toxicidade nos parÃmetros avaliados. Em todos os resultados a FAV + filme transparente foi melhor do que a FAV. EWAT macroscÃpica e escores inflamatÃrios mostraram diferenÃas significativas entre o grupo tratado, FAV + filme de poliuretano e grupo controle (p <0,01). Ãrea contraÃÃo da ferida foi aumentada em no grupo FAV grupo + filme de poliuretano, por 99,62% (84,65% vs, controle), bem como a contagem de fibroblastos (112,7  7,9 vs 80,0  6,4; controle, p < 0,01) e densidade de colÃgeno (33,9%  6,6 vs 20,9  8,6%, controle, p <0,01). FAV + filme de poliuretano aumentou a espessura da epiderme (113,2  18,1 vs 52,1  8,9, controle p <0,01) e tambÃm a contagem do nÃmero de vasos sanguÃneo no tecido conjuntivo (142,3  15,1 vs 68, 5  8,6; controle, p <0,01). O nÃmero de cÃlulas marcadas para NOSi e nitrotirosina, foi reduzido no grupo FAV + filme de poliuretano (601,5  94,0 vs 95,7  2005,0, controle, NOSi e 666,0  142,4 vs 1877,2  133, 8; controle, nitrotirosina, p <0,01). O MDA tambÃm foi reduzido pelo tratamento com FAV + filme de poliuretano (0,08  0,03 vs 0,3  0,05; controle, p <0,05). ConcluÃmos que a aplicaÃÃo tÃpica da FAV nÃo produziu efeito tÃxico e acelerou a cicatrizaÃÃo de feridas possivelmente por propriedades antioxidantes. O uso do filme de poliuretano intensificou a aÃÃo da FAV. / Pressure ulcer (PU) is a common injury among elderly and subjects with impaired physical mobility. It affects the quality of life of individuals and generates considerable costs, since it is becoming a worldwide growing problem due to the aging of the population. Cycles of ischemia and reperfusion from pressure have been identified as primary causal factor but other factors influence the intensity of damage. Currently, there is no effective and inexpensive method to treat this condition. For this reason, we aimed to check whether the traditional indication of smoke from Artemisia vulgaris (SAV) really contributes to the wound healing process of the PU. This work was approved by Ethics Committee (89/2011). It was used a non-invasive model of PU in mice which consists of 4 cycles of ischemia and reperfusion by the placement of two magnets on the dorsal skin surface of mice. Five experimental groups were tested: negative control, with ulcer and without treatment; positive control, with ulcer and treated with hydrogel and transparent film; treated group 1, with ulcer and topical SAV, treated group 2, with ulcer and topical SAV and transparent film, and a group without ulcer and without treatment. The analysis was conducted on days 5, 7, 14 and 21 after ulcer induction. Macroscopic parameters of healing were assessed through the EWAT (Experimental Wound Assessment Tool). Wound area, percentage of contraction, histopathological analysis, collagen layer thickness and collagen density in the dermis, counting of fibroblasts and fibrocytes, measurement of epidermis thickness were also assessed. Evaluation of the immunostaining for iNOS and nitrotyrosine and malondialdehyde assay (MDA) was performed to investigate oxidative stress. Toxicological tests were conducted in treated animals and SAV showed no toxic effect. In all the results SAV+film treatment was better than SAV. Results: Macroscopic EWAT and inflammatory scores showed significant differences between SAV+film treated group and control group (p<0,01). Wound contraction area was enhanced in SAV+film group by 99,62% (vs 84,65%, control) as well as fibroblast count (112,7  7,9 vs 80,0  6,4; control, p<0,01) and collagen density (33,9%  6,6 vs 20,9%  8,6; control, p<0,01). Epidermal width was increased by SAV+film (113,2  18,1 vs 52,1  8,9; control p<0.01) and also the blood vessel counting in the conjunctive tissue (142,3  15,1 vs 68,5  8,6; control, p<0.01). The counting of iNOS and nitrotyrosine immunostained cells showed a reduction by SAV+film (601,5  94,0 vs 2005,0  95,7; control, iNOS and 666,0  142,4 vs 1877,2  133,8; control, nitrotyrosine, p<0.01). MDA assay showed also a reduction by SAV+film treatment (0,08  0,03 vs 0,3  0,05; control, p<0.05). In conclusion, SAV topical application promoted wound healing by anti-oxidant properties and by modulating the inflammatory process. The effect of SAV was enhanced when the wound area was covered by the transparent film after smoke application. In addition, this method showed no toxic effect and may be an effective and low cost alternative for PU healing treatment.

Chronic wounds represent a severe socio-economic burden and a key area of unmet clinical need. PKCα is ubiquitous in the skin, particularly the epidermis and functions in numerous pathways that are fundamental to wound repair. By utilising a global PKCα-/- mouse we have identified PKCα-regulated processes both in unwounded skin and during wound healing. PKCα-/- mice display considerably delayed wound healing with a dramatic reduction in re-epithelialisation. By analysing the ultrastructure of the epidermis, I have shown that this delay directly correlates with a failure of wound edge desmosomes to switch to a their adhesive properties. A major risk factor for the development of chronic wounds is age. Crucially, this delay in modulating cell adhesion is conserved in human chronic wounds and aged murine skin. Furthermore, manipulation of PKCα using an inducible bitransgenic mouse containing epidermal specific constitutively active PKCα can accelerate the modulation of desmosome adhesion and subsequently improve re-epithelialisation. Global gene expression analysis of PKCα-/- skin and wounds revealed further defects. Upon wounding, we observed a failure to correctly regulate expression of key collagen and Wnt signalling genes that are essential for correct and timely wound healing. Finally, intrinsic gene expression changes were identified in the skin of PKCα-/- mice, specifically a downregulation of multiple extracellular matrix genes. Of note was the downregulation of small leucine-rich proteoglycans which led to alterations to dermal collagen structure and skin tensile strength. These changes render the PKCα-/- skin susceptible to breaking and wound development. To conclude, we have identified multiple roles for PKCα intrinsically in the skin and also during cutaneous wound healing. Importantly, these intrinsic changes appear to predispose PKCα-/- skin to the development of cutaneous wounds and altered wound-specific processes that manifest in a delayed healing phenotype.

Abstract The effects of perioperative filgrastim (rhG-CSF) and surgery per se on the postoperative acute phase reaction were studied by assessing leukocyte functions, cytokine levels and tenascin-C (Tn-C) and procollagen propeptide (PINP, PIIINP) concentrations in different body fluid compartments in patients undergoing gastrointestinal surgery. Thirty consecutive patients were randomized to receive either filgrastim or placebo for five days, starting 12 hours before colorectal surgery. Filgrastim treatment led to marked neutrophilia with decreased neutrophil migration in peripheral blood but not in peritoneal fluid 48 hours postoperatively. Neutrophil phagocytosis and bacterial killing did not differ between the groups. Filgrastim caused increased postoperative expression of neutrophil CD11b/CD18 in blood but not in peritoneal fluid or wound fluid. CD11b/CD18 expression was higher in both wound fluid and peritoneal fluid than in blood in the placebo group. The expression of neutrophil CD62L was higher in blood than in peritoneal fluid or wound fluid in both groups. The serum concentration of interleukin (IL)-8 was lower in the filgrastim group 5 hours postoperatively. The concentrations of IL-1β, IL-6, transforming growth factor (TGF)-β and IL-10 did not differ between the groups. The cytokine levels were markedly higher locally in the wound and in the peritoneal cavity compared to circulating blood. No adverse events attributable to filgrastim were seen. Leukocyte counts, neutrophil and monocyte functions and the levels of IL-6, IL-8 and granulocyte colony-stimulating factor (G-CSF) were measured from 18 patients before and after colorectal surgery. Surgery caused an increase in neutrophil and monocyte counts along with lymphocytopenia. Neutrophil phagocytosis was decreased 4 and 24 hours postoperatively, but normalized after that. A distinct systemic cytokine response was seen postoperatively. In a study with 24 patients, Tn-C concentration increased in wound fluid during the first postoperative week after abdominal surgery. The Tn-C level was markedly higher in wound fluid than in serum.

Prof. H. Abrahamse

M.Tech. / Low level laser therapy, commonly known as LLLT or biomodulation, is a form of phototherapy which involves the application of low power monochromatic and coherent light to injuries and lesions to stimulate healing. In the medical field, lasers are classified as high power or surgical lasers and low level lasers which are used to stimulate cellular responses. Phototherapy has been successfully used for pain attenuation and induction of wound healing in non healing defects. Even though phototherapy has been found to be beneficial in a wide variety of therapeutic applications, it has been shown that phototherapy can induce DNA damage; however this damage appears to be repairable (Houreld and Abrahamse, 2008). DNA repair is vital to cells to avoid mutation. Literature reports show that red light or phototherapy up or down regulates genes involved in DNA repair (Zhang et al., 2003). N-methylpurine DNA glycosylase (MPG) is involved in DNA repair by catalysing the excision of a variety of modified bases. The exact mechanism by which phototherapy works is still poorly understood. Several authors have demonstrated that phototherapy enhances cell proliferation and migration. However, these cellular responses seem to confuse scientists as to whether wound healing is due to cell proliferation or migration or both. To determine the effect of phototherapy on cell proliferation or migration, a mini project was conducted (Zungu et al., 2008). Thus, cell proliferation was arrested using 5 mM hydroxyurea (HU) which is an antiproliferative drug. Wounded (W) human skin fibroblast cells (WS1, ATCC iii CRL 1502) were irradiated with 5 J/cm2 using a Helium-Neon (He-Ne) laser with a wavelength (λ) of 632.8 nm on day 1 and 4. Cell morphology, viability and proliferation were measured 24 h post irradiation. Reports indicate that several cell culture studies have used HU to control proliferation (Cai et al., 2000; Hamuro et al., 2002). Thereafter, the main study which was aimed at determining the effects of phototherapy on DNA damage and gene activation related to repair using 5 or 16 J/cm2 on W human skin fibroblast (WS1) cells was performed. Both studies involved growing WS1 cells aseptically in complete minimum essential medium (MEM) with Earle’s balanced salt solution and incubated at 37 °C in 5% CO2 and 85% humidity. Normal (N) and W cell cultures were irradiated with 5 or 16 J/cm2 30 min and 72 h (day 1 and 4) post wounding. Non irradiated cells (0 J/cm2) served as controls, while irradiated cells were the experimental groups. A wound was simulated by creating a central scratch across a monolayer of cells using a sterile 1 ml pipette. A 3 mW/cm2 He-Ne laser, λ 632.8 nm, was used to irradiate cells. After a repair time of 1 or 24 h on day 4, cell morphology (microscopy), cell viability (Trypan blue exclusion test and ATP luminescent assay), proliferation (XTT assay) and DNA integrity (alkaline comet assay with and without Formamidopyrimidine glycosylase [Fpg]) were assessed. The up or down regulation of the DNA repair gene, MPG, and regulation of three reference genes namely; beta Actin (ACTB), Glyceraldehyde 3 phosphate dehydrogenase (GPDH) and Ubiquitin c (UBC) were assessed by real time reverse transcriptase polymerase chain reaction (real time RT-PCR). iv Non irradiated HU treated cells had a reduced number of cells in the central scratch compared to non irradiated non treated cells, suggesting that HU inhibited cellular proliferation. Irradiated HU treated cells showed an increased number of cells in the central scratch compared to non irradiated treated cells. This observation proved that this increase was due to the stimulatory effect of irradiation with 5 J/cm2. The addition of HU had no significant effect on cell viability. The Trypan blue exclusion test showed no significant difference in percent viability between treated and non treated cells. Irradiated non treated cells showed a significant increase in the formazan dye, which is as a result of cleavage of XTT by the mitochondrial succinate dehydrogenase in actively proliferating cells, compared to non irradiated non treated cells (P=0.01). W cells, which were not irradiated, showed incomplete wound closure at both 1 and 24 h, while W cells irradiated with 5 J/cm2 showed complete wound closure. Similarly, W cells irradiated with 16 J/cm2 showed incomplete wound closure at 1 and 24 h. Cell viability, proliferation and DNA integrity assays showed that irradiated and non irradiated N cells were not significantly affected at both 1 and 24 h post irradiation. W cells (1 h) irradiated with 5 J/cm2 showed a significant increase in percentage cell viability and ATP compared to non irradiated W cells (1 h), (P=0.05 and P=0.04 respectively), while irradiation with 16 J/cm2 showed a significant decrease (P=0.014 and P=0.02 respectively). W cells (24 h) irradiated with 5 J/cm2 also showed a significant increase in percentage cell viability and ATP when compared to non irradiated W cells (24 h), (P=0.006 and P=0.04 respectively). Contrary, irradiation with 16 J/cm2 showed a significant decrease (P<0.001 and P=0.003 respectively). v Cell proliferation results showed that irradiation with 5 J/cm2 was stimulatory while 16 J/cm2 was inhibitory. The comet assay demonstrated that N cells irradiated with 5 or 16 J/cm2 exhibited an insignificant change in DNA damage at both 1 and 24 h when compared to their respective controls. This finding is in agreement with Karu et al., (2003) who observed that phototherapy does not alter the biological activity of cells which at the time of irradiation are functioning normally. W cells (1 and 24 h) irradiated with 16 J/cm2 showed a significant increase in DNA damage compared to their respective controls. However, there was a significant decrease in damage at 24 h compared to 1 h incubation due to the activation of DNA repair mechanisms. Though not significant, comet assay with Fpg (modified comet assay) showed more DNA damage compared to comet assay without the enzyme (conventional comet assay). It can be explained that the modified comet assay detected and cleaved oxidised bases in addition to single strand breaks, which the conventional comet assay detected, suggesting that the modified comet assay is more sensitive than the conventional comet assay. After validation of the three reference genes, ACTB was chosen to be the gene with which to normalise MPG expression in WS1 cells. It was found to be the least variable; its expression was consistent in W cells as well as cells exposed to a He-Ne laser at a fluence of 5 or 16 J/cm2. It produced an acceptable correlation coefficient (R2 >0.999) and PCR efficiency (94%). Conversely, other primers like GAPDH produced a low PCR efficiency (82%), while UBC produced a low R2 (0.898). Wang et al., (2006) recommends the value of R2 to be more than 0.995 and a PCR efficiency of between 90 and 100% for PCR results to be reliable. Other researchers have not supported the use of ACTB as a reference gene, stating that it is highly regulated (Wang et al., 2006), however this study showed that ACTB was not regulated by laser irradiation (632.8 nm at 5 or 16 J/cm2). The cell culture conditions and vi laser irradiation in this study did not induce MPG expression; perhaps an alternative repair pathway might have been induced, and hence repaired the DNA damage. In conclusion, the mini project demonstrated that HU is able to inhibit cell proliferation through its cytostatic effect without affecting the viability of W WS1 cells. This study also showed that irradiation of W cells with 5 J/cm2 using the correct parameters enhances cell migration and proliferation as evidenced by the presence of more cells in the central scratch in HU treated cells, and a significant increase in cell proliferation as shown by the XTT assay in non treated cells respectively. Thus, migration and proliferation are the direct result of phototherapy as both are involved in wound closure. This study further confirmed that irradiation of W cells with 5 J/cm2 stimulated ATP production, and hence cellular viability, as well as cell proliferation and migration. Irradiation of cells with higher fluences such as 16 J/cm2 is damaging to DNA and inhibitory to cell proliferation, migration and possibly to MPG expression. The study further showed that N cells are not stimulated by phototherapy, supporting the notion that lasers stimulate compromised cells. Thus, if they are growing normally there is nothing to stimulate. This understanding helps to clarify why N cells irradiated with 5 or 16 J/cm2 had insignificant responses. Cell culture conditions, fluence and duration of exposures are important parameters that can affect gene expression, and hence documentation of all experimental conditions needs to be emphasised and published if reproducibility is to be achieved.

M.Tech. / Low Level Laser Therapy (LLLT), also known as photo-biostimulation or simply phototherapy, has widely been used in the treatment of wounds, with its history dating back to the early 1960s (Ohshiro and Calderhead, 1991). Despite some literature reporting negative and non-existent cellular responses to LLLT, a growing body of literature reports the positive and beneficial effects of LLLT. LLLT has proved to be efficient in speeding and improving the quality of wound healing. Stressed cells respond more favourably to LLLT by recovering to their most natural state and functional capability (Bernett, 1998; Karu, 1998). When healing appears to be impaired, these tissues respond positively to the appropriate doses of light, especially light that is within 600 to 1,000 nm wavelengths (Enwemeka et al., 2004). Cellular responses to LLLT include changes in mitochondrial intracellular calcium ion (Ca2+) levels, Mitochondrial Membrane Potential (MMP), Adenine Triphosphate (ATP) concentration, and cyclic 5’, 3’ Adenosine Monophosphate (cAMP) (Karu, 1998). The mitochondrion is the power house of a cell and the major location of cellular ATP synthesis (Bayens and Dominiczak, 1999). ATP is an energy rich molecule that drives processes responsible for cell growth or proliferation (Klug et al., 2003). LLLT alters intracellular pH which is related to activation of ATPase leading to an increase in ATP production in the mitochondria of the cell (Alexandratou et al., 2002; Karu, 1998). However the mechanisms by which the beneficial effects are attained by cells in stress or injury state are not clear.