Effects of different-intensity laser acupuncture at two adjacent same-meridian acupoints on nitric oxide and soluble guanylate cyclase releases in human.

OBJECTIVES: The aim of this study was to detect the influences of LA at nonacupoint and two adjacent acupoints of pericardium meridian on the releases of NO and sGC in 20 healthy subjects. METHODS: Different intensities (12, 24, 48 mW) of infrared laser were used for irradiating Jianshi (PC5), Ximen (PC4) acupoints and nonacupoint for 20, 40 minutes, respectively. Semi-circular tubes were taped to the skin surface and filled with NO-scavenging compound for 20 minutes to capture NO and sGC, which were measured using spectrophotometry in a blinded fashion. RESULTS: As the increase in the intensity of LA stimulation, the levels of NO releases over acupoints all were significantly increased, NO releases in nonacupoints following the same treatment only changed slightly, sGC amounts were observably enhanced over acupoints, but did not any change in nonacupoint area. Different intensities of LA treatments can sensitively affect the NO and sGC releases over acupoints. This indicated that LA-induced releases of the NO and sGC were specific to acupoints. CONCLUSIONS: This is the first evidence reporting that LA induced significant elevations of NO-sGC releases over acupoints, and the enhanced signal molecules contribute to local circulation, which improves the beneficial effects of the therapy.

[Comparative study of time-correlated temperature and back-scattered light intensity for human Hegu acupoint and non-acupoint tissue irradiated by near-infrared laser].

Characteristics and differences of temperature and back-scattered light intensity in different depths of 0.2, 0.4, 0.6, 0.8 and 1 mm for both human Hegu acupoint and non-acupoint tissue irradiated by 808 nm diode laser at the different power of 15, 25 and 35 mW were studied. The temperature and the back-scattered light intensity in different depths of 0.2, 0.4, 0.6, 0.8 and 1 mm for human Hegu acupoint and non-acupoint tissue were measured by using the infrared thermography and optical coherence tomography. The result shows few differences in the temperature and the back-scattered light intensity of human Hegu acupoint and non-acupoint tissue before irradiation. The temperature and back-scattered light intensity of Hegu acupoint and the non-acupoint after irradiation were significantly higher, and the temperature and back-scattered light intensity of Hegu acupoint significantly were higher than the non-acupoint areas. At 0-40 min after the irradiation, the temperature and back-scattered light intensity of Hegu acupoint and the non-acupoint area will fluctuate and gradually decrease with the passage of time. From the results above, it is clearly seen that Hegu acupoint is different from non-acupoint both in the back-scattered light intensity and temperature after irradiation, and Hegu acupoint is more sensitive to laser irradiation than non-acupoint tissue.

[In vivo reflectance spectroscopy study of different clearing agents on human skin optical clearing].

The changes of skin tissue reflectance spectroscopy before and after being treated with the optical clearing agents of three different types of optical clearing within the wavelength rang of 400-1 000 nm, and the degree of changes in reflectance spectroscopy of each group skin during 0-60 min at 580 nm in vivo were real-time dynamically researched. The reflectance spectroscopy of skin tissue before and after being dealt by the optical clearing agents of glycerol, glucose and propylene glycol was measured using a USB-4000 fiber spectrophotometer at 0, 10, 20, 30, 40, 50 and 60 min. The results showed that the reflectance spectral intensity was distinctly decreased, but the reflectance was significantly increased gradually with the time prolonged. However, different optical clearing agents have different clearing progress. The relative decrease of reflectance of palm skin tissue before and after being dealt by the optical agents of 40% glycerol, 40% glucose and 40% propylene glycol during 10, 20, 30, 40, 50 and 60 min at the wavelength 580 nm is 5%, 7%, 9%, 10%, 11% and 12%, 9%, 13%, 16%, 19%, 21% and 22%, and 14%, 22%, 29%, 32%, 34% and 35%, respectively. The significant improvement in light transmittance and enhancement of light penetration through tissue was demonstrated for all solutions. The effect and processes of optical clearing of skin tissue is not only closely related to the choosing of the clearing agent type, but also related to the treatment time with the skin tissue. The clearing progress of different type optical clearing agent showed the order of 40% propylene glycol, 40% glucose and 40% glycerol.

Using an oblique incident laser beam to measure the optical properties of stomach mucosa/submucosa tissue.

BACKGROUND: The purpose of the study is to determine the optical properties and their differences for normal human stomach mucosa/submucosa tissue in the cardiac orifice in vitro at 635, 730, 808, 890 and 980 nm wavelengths of laser. METHODS: The measurements were performed using a CCD detector, and the optical properties were assessed from the measurements using the spatially resolved reflectance, and nonlinear fitting of diffusion equation. RESULTS: The results of measurement showed that the absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at five different wavelengths vary with a change of wavelength. The maximum absorption coefficient for tissue samples is 0.265 mm-1 at 980 nm, and the minimum absorption coefficient is 0.0332 mm-1 at 730 nm, and the maximum difference in the absorption coefficients is 698% between 730 and 980 nm, and the minimum difference is 1.61% between 635 and 808 nm. The maximum reduced scattering coefficient for tissue samples is 1.19 mm-1 at 635 nm, and the minimum reduced scattering coefficient is 0.521 mm-1 at 980 nm, and the maximum difference in the reduced scattering coefficients is 128% between 635 and 980 nm, and the minimum difference is 1.15% between 890 and 980 nm. The maximum optical penetration depth for tissue samples is 3.57 mm at 808 nm, and the minimum optical penetration depth is 1.43 mm at 980 nm. The maximum diffusion constant for tissue samples is 0.608 mm at 890 nm, and the minimum diffusion constant is 0.278 mm at 635 nm. The maximum diffuse reflectance is 3.57 mm-1 at 808 nm, and the minimum diffuse reflectance is 1.43 mm-1 at 980 nm. The maximum shift Deltax of diffuse reflectance is 1.11 mm-1 at 890 nm, and the minimum shift Deltax of diffuse reflectance is 0.507 mm-1 at 635 nm. CONCLUSION: The absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at 635, 730, 808, 890 and 980 nm wavelengths vary with a change of wavelength. There were significant differences in the optical properties for tissue samples at five different wavelengths (P < 0.01).

[Reflectance spectroscopy study of low-frequency ultrasound and glycerol on skin optical clearing].

In order to find a non-invasive way to improve the efficacy of skin optical clearing with topically applied optical clearing agents, the authors researched the changes of reflectance spectroscopy of skin tissues before and after being dealt by low-frequency ultrasound and osmotic active chemical agents within the wavelength range of 400-860 nm, and the degree of changes in reflectance spectroscopy of each group skin during 0-15 min and 15-30 min at 580 nm. The measurements were performed using a AvaSpec-2048 optical fiber spectrometer with integrating-sphere setup. The results of measurements showed that there were a few changes of the reflectance spectroscopy of skin tissues in the control group (Group 1) (The skin tissue was dealt with nothing. ) during the whole observation; But in the Group 2 (The skin tissue was dealt with only low-frequency ultrasound), it was found that the reflectance of the skin tissue showed a significant increase comparing 15 min with 0 min, but the changes in reflectance of the tissues slowly restored the original form following the longer time since the ultrasound stopping; There was also a very fast changes in reflectance of the skins in the Group 3 (the skin were dealt with only 80% glycerol) compared with that in the Group 1. The authors also found that there was a very distinct decrease in the reflectance of skin tissues dealt with both low-frequency ultrasound and 80% glycerol group (Group 4), especially during the 0-15 min, and its speed was 4.0 times that of the Group 1 and 2. 3 times that of Group 3 (During 0-15 min, the reflectance of skin tissues in the Group 1 decreased 1.896%; the reflectance of skin tissue in the Group 3 decreased 3.316%; the reflectance of skin tissues in the Group 4 decreased 7.551%). From the above results, it can be clearly seen that the low-frequency ultrasound and 80% glycerol not only have synergistic effect on optical clearing of skin tissue in vitro, but can change the optical clearing of the skin tissue in a short time.

[Gastric cancer detection using kubelka-Munk spectral function of DNA and protein absorption bands].

Differential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 250 to 650 nm, pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the DNA absorption bands at 260 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 68.5% (p < 0.05), 146.5% (p < 0.05), 282.4% (p < 0.05), 32.4% (p < 0.05), 56.00 (p < 0.05) and 83.0% (p < 0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the protein absorption bands at 280 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 86.8% (p < 0.05), 262.9% (p < 0.05), 660.1% (p < 0.05) and 34% (p < 0.05), 72. 2% (p < 0.05), 113.5% (p < 0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the carotene absorption bands at 480 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 59.5% (p < 0.05), 73% (p < 0.05), 258.9% (p < 0.05), 118.7% (p < 0.05), 139.2% (p < 0.05), and 324. 6% (p < 0.05) respectively. It is obvious that pathological changes of gastric epithelial tissues induced that there were significant changes in the contents of the DNA, protein and beta-carotene of gastric epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive the optical biopsy for gastric cancer and provides a useful reference.

[Comparative study of reflectance spectroscopy of human laogong acupoint and non-acupoint tissues irradiated by near-infrared laser].

Characteristics and differences of reflectance spectroscopy of human Laogong acupoint and non-acupoint tissues before and after irradiation by different power of laser were studied in the spectral range from 400 to 1 000 nm. A wavelength 808 nm semiconductor laser was used for irradiation at the power of 20, 50 and 100 mW for ten minutes. Reflectance spectra of human Laogong acupoint and non-acupoint tissues were measured by using an AvaSpec-2048 optical fiber spectroscopy with an integrating sphere attachment. The result shows that before irradiation the shape of the reflectance spectra of Laogong acupoint and non-acupoint is similar, they have the same troughs at 423, 544, 577 and 980 nm, and the reflectance for Laogong acupoint and non-acupoint at these wavelengths is 17.1%, 26.1%, 25.9% and 35.0%, and 17.1%, 27.6%, 28.1% and 36.5% respectively. But from 475 to 1 000 nm, the reflectance of Laogong acupoint is smaller than that of non-acupoint. After being irradiated by semiconductor laser at the power of 20, 50 and 100 mW, there is a very significant decrease in the reflectance of Laogong acupoint compared to that before irradiation, and the higher the power, the lower the reflectance. But there is just a small decrease in the reflectance for non-acupoint compared to that before irradiation. From the above results, it is clearly seen that Laogong acupoint is different from non-acupoint on reflectance spectroscopy, and Laogong acupoint is more sensitive to laser irradiation than non-acupoint tissue.

[Colon adenoma detection using Kubelka-Munk spectral function of DNA and protein bands].

Differential diagnosis of human colon adenoma was studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 590 to 1 064 nm pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the DNA absorption bands at 260 nm between normal and adenomatous colon epithelial tissues, and the differences were 218% (p < 0.05) and 68.5% (p < 0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the protein absorption bands at 280 nm between normal and adenomatous colon epithelial tissues, and the differences were 208% (p < 0.05) and 59.0% (p < 0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the beta-carotene absorption bands at 480 nm between normal and adenomatous colon epithelial tissues, and the differences were 41.7% (p < 0.05) and 32.9% (p < 0.05) respectively. Obviously, pathological changes of colon epithelial tissues were induced so that there were significant changes in the contents of the DNA, protein and beta-carotene of colon epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive optical biopsy of colon adenoma, and provides a useful reference.

[Superficial bladder cancer detection using diffuse reflectance spectral ratio R540/R575 of oxygenated hemoglobin bands].

A low-cost, fast, and noninvasive method for early diagnosis of malignant lesions of mucosa tissue based on diffuse reflectance spectra was applied in the study of the optical biopsy of superficial human bladder cancer. In the present paper, differential diagnosis of superficial human bladder cancer was studied using the diffuse reflectance spectral ratio (R540/R575) of the oxygenated hemoglobin absorption bands at 540 and 575 nm in vitro. Diffuse reflectance spectra for mucosa/submucosa tissues of normal bladder and superficial bladder cancer were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that there were three the diffuse reflectance spectral dips at 415, 542 and 577 nm respectively for mucosa/submucosa tissues of normal bladder and superficial bladder cancer in the spectral range from 400 to 600 nm. The mean diffuse reflectance spectral ratio (R540/R575) of normal bladder mucosa/submucosa tissue decreased slowly with time increase after surgical excision, and the mean diffuse reflectance spectral ratio (R540/R575) of superficial bladder cancer mucosa/ submucosa tissue also decreased slowly with time increasing after surgical excision. The mean diffuse reflectance spectral ratios (R540/R575) of normal bladder mucosa/submucosa tissue were 111%, 107%, 104% and 102% after 2, 3, 4 and 5 h after surgical excision respectively, and those of superficial bladder cancer mucosa/submucosa tissue were 98.4%, 95.5%, 93.1% and 91.6% after 2, 3, 4 and 5 h after surgical excision respectively. There were significant differences in mean diffuse reflectance spectral ratio (R540/R575) for mucosa/submucosa tissues between normal bladder and superficial bladder cancer after 2, 3, 4 and 5 h after surgical excision respectively (p < 0.05). Differences in mean diffuse reflectance spectral ratio (R540/R575) for mucosa/ submucosa tissues between normal bladder and superficial bladder cancer were 12.6%, 11.5%, 10.9% and 10.4% after 2, 3, 4 and 5 h after surgical excision respectively. It is obvious that pathological changes in bladder mucosa/submucosa tissues induced changes in the component and structure of the tissues, and especially quantitative changes in oxyhemoglobin and de-oxyhemoglobin of tissues obviously. Conclusion of the study provides a new method that can be applied to rapid, low-cost and noninvasive optical biopsy of superficial bladder cancer.

[Thermal coagulation of human benign prostatic hyperplasia tissues induced changes in the absorption and scattering properties in spectral range from 590 to 1 064 nm in vitro].

The optical properties and their differences of native and coagulated human benign prostatic hyperplasia (BPH) tissues were studied in the spectral range from 590 to 1 064 nm in vitro. The measurements were performed using a spectrophotometer with an integrating sphere attachment, and the absorption and scattering properties were assessed from these measurements using the inverse adding-doubling method. The results of measurement showed that the thermal coagulation of BPH tissues induced obviously the decrease in the absorption coefficients in the spectral range from 590 to 1 064 nm. The peaks in the absorption coefficients for native and coagulated BPH tissues were respectively 0.438 and 0.416 mm(-1) corresponding to the same wavelength of 990 nm, the maximum difference in the absorption coefficients of native and coagulated BPH tissues is 86.79% at 1 064 nm, and the minimum difference is 4.74% at 920 nm. The thermal coagulation of BPH tissues induced an increase in the reduced scattering coefficients in the spectral range from 600 to 1 064 nm obviously, and induced a decrease in the reduced scattering coefficients at 590 nm obviously. The peaks in the reduced scattering coefficients for native and coagulated BPH tissues were respectively 1.090 and 1. 449 mm(-1) corresponding to the same wavelength of 970 nm, and other peaks in the reduced scattering coefficients for native and coagulated BPH tissues were respectively 1.116 and 1.627 mm(-1) corresponding to the same wavelength of 1 050 nm, the maximum difference in the reduced scattering coefficients of native and coagulated BPH tissues is 47.73% at 1 064 nm, and the minimum difference is 4.86% at 600 nm.

[Absorption and scattering characteristics of human benign prostatic hyperplasia tissue with Ti: sapphire laser irradiation in vitro].

The optical properties and their differences of human benign prostatic hyperplasia (BPH) tissues removed using transurethral plasma kinetic resection of the prostate (PKRP) and transurethral vaporization of the prostate (TUVP) at 640, 660, 680, 700, 720, 740, 760, 780, 800, 820, 840, 860 and 880 nm of Ti: Sapphire laser were studied in vitro. The measurements were performed using a double-integrating-sphere setup, and the absorption and scattering properties were assessed using the inverse adding-doubling method. The results of measurement showed that the absorption coefficients and reduced scattering coefficients of BPH tissues removed using PKRP and TURP obviously decreased with the increase in the wavelength for thirteen different laser wavelengths. The absorption coefficient and reduced scattering coefficient of BPH tissues removed using PKRP at a certain laser wavelength were obviously smaller than that of BPH tissues removed using TUVP at the same laser wavelength. The maximum absorption coefficient and maximum reduced scattering coefficient of BPH tissues removed using PKRP and TURP were respectively (0. 885 +/- 0. 022) and (0.955 +/- 0.024)mm(-1), and (1.564 +/- 0.039) and (1.658 +/- 0.042)mm(-1) at 640 nm, their differences were respectively 7.91% and 6.01%, and the minimum absorption coefficient and minimum reduced scattering coefficient of BPH tissues removed using PKRP and TURP were respectively (0.443 +/- 0.011) and (0.455 +/- 0.011) mm(-1), and (1.117 +/- 0.028) and (1.197 +/- 0.030)mm(-1) at 640 nm, their differences were respectively 2.71% and 9.13%. The maximum difference in the absorption coefficients of BPH tissues removed using PKRP and TURP is 8.95% at 660 nm, and the minimum difference is 1.75% at 860 nm. The maximum difference in the reduced scattering coefficients of BPH tissues removed using PKRP and TURP is 9.13% at 800 nm, and the minimum difference is 6.01% at 640 nm.

[Canceration and thermal coagulation of human liver induced changes in the absorption and scattering properties of liver-tissue at near infrared in vitro].

Canceration and thermal coagulation of human liver induced changes in the absorption and scattering properties of liver tissue at 710, 730, 750, 77, 790, 810, 830, 850, 870 and 890 nm of Ti: sapphire laser were studied in vitro. The measurements were performed using a double-integrating-sphere setup, and the absorption and scattering properties were assessed from these measurements using the inverse adding-doubling method. The results of measurement showed that canceration of liver induced significant decrease in the absorption coefficients of liver tissue, and the maximum change in the absorption coefficients is 86.12% at 850 nm, while the minimum change in the absorption coefficients is 82.65% at 750 nm. Thermal coagulation of normal liver induced obvious change in the absorption coefficients from 710 to 890 nm, and the maximum change in the absorption coefficients is 79.55% at 710 nm, while the minimum change in the absorption coefficients 0.72% at 790 nm. Thermal coagulation of carcinoma liver tissue induced significant increase in the absorption coefficients, the maximum change in the absorption coefficients of carcinoma liver tissue is 78.69% at 810 nm, in the minimum change in the absorption coefficients of carcinoma liver tissue 38.16% at 710 nm. Canceration of liver induced significant increase in the scattering coefficients of liver tissue, and the maximum change in the scattering coefficients is 158.37% at 710 nm, while the minimum change in the scattering coefficients is 136.03% at 890 nm. Thermal coagulation of normal liver induced significant increase in the scattering coefficients of liver tissue, and the maximum change in the scattering coefficients is 632.92% at 890 nm, while the minimum change for the scattering coefficients is 587.40% at 710 nm. Thermal coagulation of carcinoma liver tissue induced significant increase in the scattering coefficients, and the maximum change in the scattering coefficients of carcinoma liver tissue is 384. 25% at 810 nm, while the minimum change in the scattering coefficients of carcinoma liver tissue is 330. 86% at 710 nm. The change in the absorption and scattering properties also varies with the change of laser wavelength.

Changes in Nitric Oxide Releases of the Contralateral Acupoint during and after Laser Acupuncture at Bilateral Same-Name Acupoints in Human.

OBJECTIVE: The purpose of the study was to examine the effects of laser acupuncture (LA) at right Neiguan (RPC6)/left Neiguan (LPC6) acupoints on the releases of nitric oxide (NO) in the treated and contralateral/nontreated PC6, compared to the nonacupoint control area. METHODS: 24 mW LA at RPC6, LPC6, and nonacupoint in 22 healthy subjects for 40 min: sterilized dialysis tube was taped to the nontreated PC6/nonacupoint during the treatment and immediately taped to the treated and nontreated PC6/nonacupoint after LA removal. NO-scavenging compound was injected into the tube for 40 min to absorb the molecular which was tested by spectrophotometry in a blinded fashion. RESULTS: LA-induced NO releases over PC6 acupoints for the nontreated and treated sides all significantly increased after LA removal, but for the nontreated acupoints they did not change during LA stimulation. LA at RPC6 induced the more release of the NO at contralateral side than stimulating LPC6, but not on nonacupoints. The results suggest that LA-induced NO release over contralateral acupoint and NO release resulting from the lateralized specificity all are different and specific to the acupoint within different time course. CONCLUSIONS: LA-evoked NO release over acupoints could improve the neurogenic, endothelial activity of the vessel wall to further facilitate microcirculation.

[Comparison of light attenuation characteristics and optical penetration depths between native and coagulated human liver tissues].

A double-integrating-spheres and IAD method were used to study the differences in the optical penetration depths (OPDs) and light attenuation (LA) native and coagulated human liver tumors and liver tissues at the wavelengths of 680, 720, 780, 810, 850 and 890 nm of Ti: Sapphire laser. The results of measurement showed that the OPDs for native and coagulated human liver tumors and liver tissues at six different wavelengths obviously increase with increasing laser wavelength, the OPDs of coagulated human liver tumors and liver tissues at six different wavelengths were significantly smaller than that of native human liver tumors and liver tissues at the same wavelength respectively (P<0.05), and the OPDs of native and coagulated human liver tumors at six different wavelengths were significantly bigger than that of native and coagulated human liver tissues at the same wavelength respectively (P<0.05). The LA for native and coagulated human liver tumors and liver tissues at six different wavelengths obviously decreases with increasing laser wavelength, and the LA for coagulated human liver tumors and liver tissues at six different wavelengths is significantly bigger than that for native human liver tumors and liver tissues at the same wavelength respectively (P<0.05). The LA for native and coagulated human liver tumors at six different wavelengths is significantly bigger than that for native and coagulated human liver tissue at the same wavelength respectively (P<0.05).

Differences in optical properties between healthy and pathological human colon tissues using a Ti:sapphire laser: an in vitro study using the Monte Carlo inversion technique.

The purpose of the study is to analyze and compare differences in the optical properties between normal and adenomatous human colon tissues in vitro at 630-, 680-, 720-, 780-, 850-, and 890-nm wavelengths using a Ti:sapphire laser. The optical parameters of tissue samples are determined using a double integrating sphere setup at seven different laser wavelengths. The inverse Monte Carlo simulation is used to determine the optical properties from the measurements. The results of measurement show that the optical properties and their differences vary with a change of laser wavelength for normal and adenomatous colon mucosa/submucosa and normal and adenomatous colon muscle layer/chorion. The maximum absorption coefficients for normal and adenomatous human colon mucosa/submucosa are 680 nm, and the minimum absorption coefficients for both are 890 nm. The maximum difference of the absorption coefficients between both is 56.8% at 780 nm. The maximum scattering coefficients for normal and adenomatous colon mucosa/submucosa are 890 nm, and the minimum scattering coefficients for both are 780 nm. The maximum difference of the scattering coefficients between both is 10.6% at 780 nm. The maximum absorption coefficients for normal and adenomatous colon muscle layer/chorion are 680 nm, and the minimum absorption coefficients for both are 890 nm. The maximum difference of the absorption coefficients between both is 47.9% at 780 nm. The maximum scattering coefficients for normal and adenomatous colon muscle layer/chorion are 890 nm, and the minimum scattering coefficients for both are 680 nm. The maximum difference of the scattering coefficients between both is 9.61% at 850 nm. The differences in absorption coefficients between normal and adenomatous tissues are more significant than those in scattering coefficients.

Determination of optical properties of normal and adenomatous human colon tissues in vitro using integrating sphere techniques.

AIM: The purpose of the present study is to compare the optical properties of normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion in vitro at 476.5, 488, 496.5, 514.5 and 532 nm. We believe these differences in optical properties should help differential diagnosis of human colon tissues by using optical methods. METHODS: In vitro optical properties were investigated for four kinds of tissues: normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion. Tissue samples were taken from 13 human colons (13 adenomatous, 13 normal). From the normal human colons a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion), and from the adenomatous human bladders a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion). The measurements were performed using a double-integrating-sphere setup and the optical properties were assessed from these measurements using the adding-doubling method that was considered reliable. RESULTS: The results of measurement showed that there were significant differences in the absorption coefficients and scattering coefficients between normal and adenomatous human colon mucosa/submucosa at the same wavelength, and there were also significant differences in the two optical parameters between both colon muscle layer/chorion at the same wavelength. And there were large differences in the anisotropy factors between both colon mucosa/submucosa at the same wavelength, there were also large differences in the anisotropy factors between both colon muscle layer/chorion at the same wavelength. There were large differences in the value ranges of the absorption coefficients, scattering coefficients and anisotropy factors between both colon mucosa/submucosa, and there were also large differences in these value ranges between both colon muscle layer/chorion. There are the same orders of magnitude in the absorption coefficients for four kinds of colon tissues. The scattering coefficients of these tissues exceed the absorption coefficients by at least two orders of magnitude. CONCLUSION: There were large differences in the three optical parameters between normal and adenomatous human colon mucosa/submucosa at the same laser wavelength, and there were also large differences in these parameters between both colon muscle layer/chorion at the same laser wavelength. Large differences in optical parameters indicate that there were large differences in compositions and structures between both colon mucosa/submucosa, and between both colon muscle layer/chorion. Optical parameters for four kinds of colon tissues are wavelength dependent, and these differences would be useful and helpful in clinical applications of laser and tumors photodynamic therapy (PDT).

Optical properties of human normal small intestine tissue determined by Kubelka-Munk method in vitro.

AIM: To study the optical properties of human normal small intestine tissue at 476.5 nm, 488 nm, 496.5 nm, 514.5 nm, 532 nm, 808 nm wavelengths of laser irradiation. METHODS: A double-integrating-sphere system, the basic principle of measuring technology of light radiation, and an optical model of biological tissues were used in the study. RESULTS: The results of measurement showed that there were no significant differences in the absorption coefficients of human normal small intestine tissue at 476.5 nm, 488 nm, 496.5 nm laser in the Kubelka-Munk two-flux model (P>0.05). The absorption coefficients of the tissue at 514.5 nm, 532 nm, 808 nm laser irradiation were obviously increased with the decrease of these wavelengths. The scattering coefficients of the tissue at 476.5 nm, 488 nm, 496.5 nm laser irradiation were increased with the decrease of these wavelengths. The scattering coefficients at 496.5 nm, 514.5 nm, 532 nm laser irradiation were obviously increased with the increase of these wavelengths. The scattering coefficient of the tissue at 532 nm laser irradiation was bigger than that at 808 nm. There were no significant differences in the total attenuation coefficient of the tissue at 476.5 nm and 488 nm laser irradiation (P>0.05). The total attenuation coefficient of the tissue at 488 nm, 496.5 nm, 514.5 nm, 532 nm, 808 nm laser irradiation was obviously increased with the decrease of these wavelengths, and their effective attenuation coefficient revealed the same trend. There were no significant differences among the forward scattered photon fluxe, backward scattered photon fluxe, and total scattered photon fluxe of the tissue at 476.5 nm, 488 nm, 496.5 nm laser irradiation. They were all obviously increased with attenuation of tissue thickness. The attenuations of forward and backward scattered photon fluxes, and the total scattered photon fluxe of the tissue at 514.5 nm laser irradiation were slower than those at 476.5 nm, 488 nm, 496.5 nm laser irradiation respectively. The attenuations of forward and backward scattered photon fluxes, and total scattered photon fluxes at 532 nm laser irradiation were obviously slower than those at 476.5 nm, 488 nm, 496.5 nm, 514.5 nm laser irradiation. The attenuations of forward and backward scattered photon fluxes, and total scattered photon fluxe at 808 nm laser irradiation were all obviously slower than those at 476.5 nm, 488 nm, 496.5 nm, 514.5 nm, 532 nm laser irradiation respectively. CONCLUSION: There are significant differences in optical parameters of human normal small intestine tissue in the Kubelka-Munk two-flux model at six different wavelengths of laser radiation. The results would provide a new method of information analysis for clinical diagnosis.

[Comparative research on attenuation characteristics of human bladder cancer tissue at different wavelengths of laser and their linearly polarized laser in vitro].

In this paper, a double-integrating-spheres system, the basic principle of measuring technology of ray radiation, and the optical model of biological tissues were used for the study. Attenuation characteristics of human bladder cancer tissue at 467.5, 488, 496.5, 514.5 and 532 nm laser and their linearly polarized laser irradiation were studied. The results of measurement showed that the attenuation characteristics of human bladder cancer tissue in Kubelka-Munk two-flux model were different at different wavelengths of laser irradiation in the range of five different laser wavelengths. There were significant differences in the total attenuation or effective attenuation coefficients of human bladder cancer tissue at 476.5, 496.5, and 532 nm wavelengths of laser and their linearly polarized laser irradiation (P>0.05), and there were no significant differences at 488 and 514.5 nm wavelengths of laser and their linearly polarized laser irradiation in two-flux model (P>0.05). The total attenuation and effective attenuation coefficients of human bladder cancer tissue at 532 nm laser and its linearly polarized laser irradiation were obviously bigger than those at other four different wavelengths of laser and their linearly polarized laser irradiation in two-flux model. The total attenuation and effective attenuation coefficients of human bladder cancer tissue at five different wavelengths of laser and their linearly polarized laser irradiation increased with the decrease of these wavelengths, there were significant differences in those at 476.5, 496.5 and 514.5 nm wavelengths of laser and their linearly polarized laser irradiation (P<0.05), and there were no significant differences in those at 488 and 532 nm wavelengths of laser and their linearly polarized laser irradiation in light transport theory (P>0.05).

[Optical properties of human normal bladder tissue at five different wavelengths of laser and their linearly polarized laser irradiation in vitro].

A double-integrating-spheres system, the basic principle of measuring technology of radiation, and an optical model of biological tissues were used for the study. Optical properties of human normal bladder tissue at 476.5, 488, 496.5, 514.5 and 532 nm of laser and their linearly polarized laser irradiation were studied. The results of measurement showed that total attenuation coefficient and scattering coefficient of human normal bladder tissue at these wavelengths of laser and their linearly polarized laser irradiation increased with decreasing wavelengths. And these was an obvious distinction between the results at these wavelengths of laser and their linearly polarized laser irradiation. Absorption coefficient of human normal bladder tissue at these wavelengths of laser and their linearly polarized laser irradiation was tardily increased with decreasing wavelengths. But there were a number of gurgitations. And these were independent of the wavelengths of laser or their linearly polarized laser irradiation. Mean cosine of scattering of human normal bladder tissue at these wavelengths of laser and their linearly polarized laser irradiation also increased with decreasing wavelengths. And these was an obvious distinction with these wavelengths of laser and their linearly polarized laser irradiation. But penetration depth of human normal bladder tissue at these wavelengths of laser and their linearly polarized laser irradiation also increased with increasing wavelengths. But there were a number of gurgitations. Refractive index of human normal bladder tissue at these wavelengths of laser ranged from 1.37 to 1.44. Absorption coefficient, scattering coefficient, total attenuation coefficient, and effective attenuation coefficients of human normal bladder tissue in Kubelka-Munk two-flux model at the same wavelength of laser and the linearly polarized laser irradiation do not exhibit prominent distinction (P > 0.05). Some absorption coefficient, scattering coefficient, total attenuation coefficient, and effective attenuation coefficient of human normal bladder tissue in Kubelka-Munk two-flux model at different wavelengths of laser and their linearly polarized laser irradiation exhibit obvious distinction.

[Optical properties of human normal small intestine tissue with theoretical model of optics about biological tissues at Ar+ laser and 532 nm laser and their linearly polarized laser irradiation in vitro].

A double-integrating-spheres system, basic principle of measuring technology of ray radiation, and optical model of biological tissues were used for the study. Optical properties of human normal small intestine tissue at 476.5, 488, 496.5, 514.5 and 532 nm laser and their linearly polarized laser irradiation were studied. The results of measurement showed that the total attenuation coefficient and scattering coefficient of the tissue at these wavelengths of laser and their linearly polarized laser irradiation increased with decreasing wavelengths. And obviously there was a distinction at 514.5 to 532 nm wavelength between lasers and their linearly polarized laser irradiation. Absorption coefficient of tissue at these wavelengths of laser and their linearly polarized laser irradiation increased with decreasing wavelengths. Absorption coefficient of tissue at 514.5 to 532 nm wavelength of laser was obviously decreasing, which was independent of these wavelengths of laser or their linearly polarized laser irradiation. Mean cosine of scattering of tissue at these wavelengths of laser and their linearly polarized laser irradiation also increased with decreasing wavelengths. But penetration depth of tissue at these wavelengths of laser and their linearly polarized laser irradiation also increased with increasing of wavelengths. Refractive index of tissue between these wavelengths of laser was within 1.38 to 1.48. Absorption coefficient, scattering coefficient, total attenuation coefficient, effective attenuation coefficients of tissue in Kubelka-Munk two-flux model at the same wavelength of laser and their linearly polarized laser irradiation showed no prominent distinction (P>0.01). Absorption coefficient, scattering coefficient, total attenuation coefficient, effective attenuation coefficients of tissue in Kubelka-Munk two-flux model at different wavelength of laser and their linearly polarized laser irradiation showed obvious distinction. Optical properties of tissue at 514.5 to 532 nm wavelength of laser exhibited obvious distinction.