Hemoglobin (Hb), as one of main components of blood, has a unique quaternary structure. Its release of oxygen is controlled by oxygen partial pressure (PO2). We investigate the specific spectroscopic changes in Hb under different PO2 levels to optimize clinical methods of measuring tissue PO2. The transmissivity of Hb under different PO2 levels is measured with a UV/Vis fiber optic spectrometer. Its plotted absorption spectral curve shows two high absorption peaks at 540 and 576 nm and an absorption valley at 560 nm when PO2 is higher than 100 mm Hg. The two high absorption peaks decrease gradually with a decrease in PO2, whereas the absorption valley at 560 nm increases. When PO2 decreases to approximately 0 mm Hg, the two high absorption peaks disappear completely, while the absorption valley has a hypochromic shift (8 to 10 nm) and forms a specific high absorption peak at approximately 550 nm. The same phenomena can be observed in visible reflectance spectra of finger-tip microcirculation. Specific changes in extinction coefficient and absorption spectra of Hb occur along with variations in PO2, which could be used to explain pathological changes caused by tissue hypoxia and for early detection of oxygen deficiency diseases in clinical monitoring.
Previous studies have demonstrated the ultrasound-induced skin optical clearing enhancement with topical application of 60% glycerol (G) on in vitro porcine skin and in vivo human skin. Our purpose was to find the relation between the effect of optical skin clearing and different concentrations of glycerol and to find more effective ultrasound-glycerol combinations on optical skin clearing. The enhancement effect of ultrasound [Sonophoresis (SP) delivery] in combination with 40% G, 60% G, and 80% G on in vitro human skin optical clearing was investigated. Light imaging depths of skin were measured using optical coherence tomography. Different concentrations of glycerol and ultrasound with a frequency of 1 MHz and an intensity of 0.5 W/cm2 was simultaneously applied for 15 min. The results show that with the increase of concentration of glycerol, the optical clearing of skin is much improved. Optical clearing capability of glycerol was more enhanced with simultaneous application of ultrasound compared with glycerol alone. The attenuation coefficients of skin tissues after application of 40% G/SP, 60% G/SP, and 80% G/SP decreased approximately 11.8%, 18.5%, and 20.0% at 15 min compared with 40% G, 60% G, and 80% G alone, respectively. The greatest decrease in attenuation coefficients at 60 min was approximately 52.3% and 63.4% for 80% G (without ultrasound) and 80% G/SP (with ultrasound), respectively, which are 2.1-fold and 2.6-fold to that in the 40% G.
Noninvasive tumor imaging could lead to the early detection and timely treatment of cancer. Optical coherence tomography (OCT) has been reported as an ideal diagnostic tool for distinguishing tumor tissues from normal tissues based on structural imaging. In this study, the capability of OCT for functional imaging of normal and tumor tissues based on time- and depth-resolved quantification of the permeability of biomolecules through these tissues is investigated. The orthotopic graft model of gastric cancer in nude mice is used, normal and tumor tissues from the gastric wall are imaged, and a diffusion of 20% aqueous solution of glucose in normal stomach tissues and gastric tumor tissues is monitored and quantified as a function of time and tissue depth by an OCT system. Our results show that the permeability coefficient is (0.94±0.04)×10−5 cm/s in stomach tissues and (5.32±0.17)×10−5 cm/s in tumor tissues, respectively, and that tumor tissues have a higher permeability coefficient compared to normal tissues in optical coherence tomographic images. From the results, it is found that the accurate and sensitive assessment of the permeability coefficients of normal and tumor tissues offers an effective OCT image method for detection of tumor tissues and clinical diagnosis.
Tongue inspection (TI) is an important and unique diagnostic method in traditional Chinese medicine (TCM), because significant connections between various viscerae diseases and abnormalities in the tongue have been verified. In TCM, TI is simple and non invasive, but in clinical applications, TI is subjectively based on the experience and technique of physicians. To avoid this problem, optical coherence tomography (OCT) imaging is introduced here for TI. We study OCT imaging in rats in vivo from chronic gastritis group (model) and normal group (control) and quantitatively analyze the relative parameters, such as the thickness and the moisture degree of TI. Our results show that OCT images properly demonstrate the thickness of the tongue coating and the moisture degree of the tongue in both groups, and the thickness is increased in the model group from that in the normal group, while the moisture degree decreases. As a result, OCT technology has the potential to provide physicians with an objective diagnostic standard for visual TI in TCM clinical practice and research.
Inspection of tongue is an age-old technique used by Traditional Chinese Medicine (TCM) practitioners to determine a
patient's health status. Because tongue examination is a subjective and inaccurate diagnostic method, a scientific tool
which can provide objective and accurate information is needed to assist the TCM practitioners in their practice. The
purpose of the study was to examine the feasibility of developing a glossoscopy from an optical coherence tomography
(OCT) imaging system. In the present study, an OCT system was used to examine the tongue of the rat. After
examination, the tongue was surgically removed, sectioned by a microtome and put on a glass slide for histological
examination. The slides were examined under a bright-field microscope. Results of the OCT imaging studies showed that
the OCT system was capable of showing the images of three distinct regions of the tongue: the tongue coating layers, the
interface between the tongue coating and the tongue body, and the tongue body. It was also possible to assign an index
number to each of the coating layers. When the tongue tissue was examined under a microscope, three separate regions
of the tongue also were visible. Results of this pilot study shows that the OCT potentially can be developed into a
glossoscopy for clinical application in TCM practice.
Matrix Metalloproteinase (MMP) plays an active role in remodeling cartilage in osteoarthritic cartilage. To find an
effective method of prevention of osteoclasia, this in vitro study focuses on the expression of MMP-3 and MMP-13 in
the SW1353 cells by LED irradiation. The human chondrosarcoma cell line SW1353 were stimulated with the
proinflammatory cytokine IL-1beta or tumor necrosis factor-alpha (TNF-alpha), and were received the irradiation of
LED (632nm, 4mW/cm2). The cell count was assessed over a 96-hour period by using Trypan blue dye exclusion assay,
and the cell activity was evaluated with a Cell Counting Kit-8 Assays. The subsequent expression of MMP-3 and
MMP-13 was quantified. Results of this experiment showed that the cultural cell activity was decreased, and the
expression of MMP-3 and MMP-13 was increased by being stimulated with IL-1beta or TNF-alpha. After received LED
irradiation, the death rate of cultural cell was increased and the expression of MMP-3 and MMP-13 was decreased
significantly. The present study concluded that particular LED irradiation stimulates SW1353 cell proliferation activity
and inhibit the MMP-3 and MMP-13 enzymatic activity. These findings might be clinically relevant, indicating that the
low power laser irradiation treatment is likely to achieve the repair of articular cartilage in clinic.
Based on Pennes equation, the influences of the intensity and the impulse frequency of laser acupuncture on the point tissues' blood flow perfusion rate are discussed. We find that the blood perfusion rate of point tissue increases with the intensity of laser acupuncture increasing. After impulse laser acupuncture the point tissue blood perfusion rate increase little, but after continuum laser acupuncture the point tissues blood perfusion rate increase much.
Ulcerative colitis (UC) is an inflammatory destructive disease of the large intestine occurred usually in the rectum and lower part of the colon as well as the entire colon. In this paper, the influence of IL-1α and IL-4 on the experimental ulcerative colitis by light emitting diode ( LED ) (λ: 632.8nm; power: 4.0mw) applied to colon directly were studied. Making 30 rats into 3 groups: LED curative group, model group, normal control group. There were 10 rats of each group. We used glacial acetic acid (5%) and trinitro-benzene-sulfonic acid (TNBS) (1%) intra-anally to replicate the rat model of ulcerative colitis. After a week treatment with administrating LED rectal irradiation to curative group, 30mm each time, once per day, the histopathological studies in colonic tissue were performed, and the expression and distribution of IL-lα and IL-4 in colonic tissues were investigated by immunohistochemical staining. The extent of the Colonic tissue injury in LED curative group was not as significant as that in the model group. Compared with model group, the content of MDA in LED curative group was reductived and the activity of SOD was increased significantly, and the expression and distribution of IL-lα in LED curative group was depressed significantly, however the expression and distribution of IL-4 in LED curative group was increased obviously. This results show that the LED rectal irradiation can protect colonic mucosa from the experimental ulcerative colitis in rats, and suggest that the effects may be related to the photobiomodulation and immunomodulation of LED.
We evaluated the effects of light emitting diode(LED λ 632.8nm; power 4.0mw)applied directly to the colon on the experimental ulcerative colitis. 34 rats were divided into 3 groups, which was LED treatment group (n=12), model group (n=12), and normal control group (n=10). Given glacial acetic acid (5%) intra-anally so as to be replicated the rat model of ulcerative colitis. LED irradiation was used to curative group, with 30min each time, once per day. The period of treatment was one week. Then the activity of superoxide dismutase (SOD) and content of malondi-aldehyde (MDA) in the blood plasma were detected and the histopathological study in Colonic tissue was performed. The degree of the Colonic tissue injury in curative group was not as significant as that in the model group. Comparing with model group, the Content of MDA in LED curative group was reductive and the activity of SOD was increased significantly. We concluded that the LED irradiation can protect colonic mucosa from acetic acid induced damage in rats and the effects may be related to the photobiomodulation of LED.
Temperature is a long established indicator of health. With the advancement of clinical medicine in thermal disease diagnostics, understanding the thermal life phenomena and temperature behavior has become increasingly important. The biological effects of human exposure to low-intensity laser irradiation thermo-therapy, the best established are those due to elevation of tissue temperature. Bio-heat equations (BHEs) are necessary for predicting tissue temperature during thermal treatment. To prevent harmful levels of heating, restrictions have been proposed on low-intensity laser irradiation as the external spatial heating. In this paper, considering the different properties for the pathological tissue and the normal tissue, using a numerical method to solve the Pennes’ bio-heat equation, we analyzed theoretically the relationship between the temperature distribution and external spatial heating during low-intensity laser irradiation. The effects of the thermal parameters such as the heat conductivity, blood perfusion rate, and metabolic rate of the tissues on the temperature distribution were discussed. The results can be used to predicted different effects on the temperature variation and distribution, the thermal damage distribution and the thermal damage volume etc. The results are also useful in optimizing the therapeutic parameters for improved low-intensity laser irradiation treatments and for better understanding the thermal life phenomena in living tissues.
In the orthopaedic field, the repair of ariticular cartilage is still a difficult problem, because of the physiological characters of cartilaginous tissues and chondrocytes. To find an effective method of stimulating their regeneration, this in vitro study focuses on the biostimulation of rabbit articular chondrocytes by low-power He-Ne laser. The articular chondrocytes isolated from the cartilage of the medial condyle of the femur of the rabbit were incubated in HamF12 medium. The second passage culture were spread on 24 petri dishes and were irradiated with laser at power density of 2 - 12 mW/cm2 for 6.5 minutes, corresponding to the energy density of 1-6 J/cm2. Laser treatment was performed three times at a 24-hour interval. After lasering, incubation was continued for 24 hours. Non-irradiated cells were kept under the same conditions as the irradiated ones. The cell proliferation activity was evaluated with a XTT colorimetric method. Irradiation of 4 - 6 J/cm2 revealed a considerably higher cell proliferation activity comparing to control cultures. Thereinto, the energy density of 4 and 5 J/cm2 remarkably increased cell growth (P<0.01). The present study showed that a particular laser irradiation stimulates articular chondrocytes proliferation. These findings might be clinically relevant, indicating that low-power laser irradiation treatment is likely to achieve the repair of articular cartilage in clinic.
Liu TCY et al have suggested the membrane receptor mediated signal transduction mechanism (STM) on photobiomodulation, which was verified by successful applications. In this paper, STM is extended to virus, and called electron excitation. As the frequency of the absorption light of envelope glycoproteins is greater than the one of light from UVA (320-400 nm) to IR, the envelope glycoprotein absorption of the light is non-resonant, and its transition rate is extraordinarily small, but can be amplified by the coherent state of the identical and independent envelope glcyoproteins. We apply VSTM to discuss the possibility that light from UVA to IR is used to inactivate the coronavirus of severe acute respiratory syndrome.
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