Yang Hq

In vivo quantification of propylene glycol, glucose and glycerol diffusion in human skin with optical coherence tomography

The purpose of study is to quantify and compare diffusion of propylene glycol, glucose, glycerol in the human skin in vivo noninvasively. Optical coherence tomography (OCT) was utilized in the functional imaging of optical cleaning agents for monitoring and quantifying the permeability coefficients (PCs) of them. Our experiments showed that the permeability coefficient of 40% propylene glycol from different subjects was averaged and found to be (2.52 ± 0.02) × 10−6 cm/s, the permeability coefficient of 40% glucose was (1.94 ± 0.05) × 10−6 cm/s, and the permeability coefficient of 40% glycerol was (1.82 ± 0.04) × 10−6 cm/s. The results indicated that the diffusion of propylene glycol solutions was faster than that of glucose solution, and the diffusion of glucose solutions was faster than that of glycerol solutions. The dependence of the permeability on the different hyperosmotic analytes could potentially be used in various basic science and clinical fields, such as optical clearing of tissues and cells as well as in clinical pharmacology.

Establishing diagnostic features for identifying the mucosa and submucosa of normal and cancerous gastric tissues by multiphoton microscopy

BACKGROUND Establishing diagnostic features is essential and significant for developing multiphoton endoscopy to make an early diagnosis of gastric cancer at the cellular level. Until now, these diagnostic features have not been clearly described and understood. DESIGN Study of diagnostic features based on multiphoton microscopy (MPM). OBJECTIVE Establishing diagnostic features to identify the mucosa and submucosa of human normal and cancerous gastric tissues by investigating their multiphoton microscopic images. SETTING Fujian Normal University and Fujian Provincial Tumor Hospital. PATIENTS Ten pairs of normal and cancerous specimens were obtained from 10 patients (ages 51-68 years) undergoing radical gastrectomy. INTERVENTIONS MPM was performed on specimens. MAIN OUTCOME MEASUREMENTS Establishment of diagnostic features. RESULTS MPM has the ability to exhibit not only the mucosal and submucosal microstructures of normal and cancerous gastric tissues but also the distribution and content of abnormal cells in these 2 layers. More importantly, it can provide the diagnostic features to qualitatively and quantitatively differentiate between normal and cancerous gastric tissues. LIMITATIONS The selection bias and preparation of specimen. CONCLUSIONS These findings provide the groundwork for further establishing diagnostic criteria.

Differentiating keloids from normal and hypertrophic scar based on multiophoton microscopy

We use a novel nonlinear optical technique, multiphoton microscopy, to differentiate keloids from hypertrophic and normal scars through the morphological and quantitative analysis of collagen and elastin in superficial dermis of scar tissues and boundary between normal skin and scar tissue.

Heat treatment of human esophageal tissues: Effect on esophageal cancer detection using oxygenated hemoglobin diffuse reflectance ratio

The main objective of the present work is to study the influence of heat treatment on the esophageal cancer detection using the diffuse reflectance (DR) spectral intensity ratio R540/R575 of oxygenated hemoglobin (HbO2) absorption bands to distinguish the epithelial tissues of normal human esophagus and moderately differentiated esophageal squamous cell carcinoma (ESCC) at different heat treatment temperature of 20, 37, 42, 50, and 60°C, respectively. The DR spectra for the epithelial tissues of the normal esophagus and ESCC in vitro at different heat-treatment temperature in the wavelength range 400–650 nm were measured with a commercial optical fiber spectrometer. The results indicate that the average DR spectral intensity overall enhancement with concomitant increase of heat-treatment temperature for the epithelial tissues of normal esophagus and ESCC, but the average DR spectral intensity for the normal esophageal epithelial tissues is relatively higher than that for ESCC epithelial tissues at the same heat-treatment temperature. The mean R540/R575 ratios of ESCC epithelial tissues were always lower than that of normal esophageal epithelial tissues at the same temperature, and the mean R540/R575 ratios of the epithelial tissues of the normal esophagus and ESCC were decreasing with the increase of different heat-treatment temperatures. The differences in the mean R540/R575 ratios between the epithelial tissues of normal esophagus and ESCC were 13.33, 13.59, 11.76, and 11.11% at different heat-treatment temperature of 20, 37, 42, and 50°C, respectively. These results also indicate that the DR intensity ratio R540/R575 of the hemoglobin bands is a useful tool for discrimination between the epithelial tissues of normal esophagus and ESCC in the temperature range from room temperature to 50°C, but it was non-effective at 60°C or over 60°C.

Effect of differently sized nanoparticles’ accumulation on the optical properties of ex vivo normal and adenomatous human colon tissue with OCT imaging and diffuse reflectance spectra

Using optical coherence tomography (OCT) and diffuse reflectance spectra, we investigated the dynamics of titanium dioxide (TiO2) nanoparticles, of different sizes, when penetrating and accumulating in human normal colon tissue (NC) and adenomatous colon tissue (AC). The process of nanoparticle penetration and accumulation in biotissue is accompanied by changes in the optical properties of tissue. Continuous OCT monitoring showed that, after application of TiO2 nanoparticles, the OCT signal intensities of NC and ac both increase with time, and the larger nanoparticles tend to produce a greater signal enhancement in the same type of tissue. The average attenuation coefficient decreased from 4.03 ± 0.36 to 2.68 ± 0.24 mm−1 at approximately 127 min for NC with 60 nm TiO2, from 4.14 ± 0.38 to 2.91 ± 0.27 mm−1 at about 148 min for NC with 100 nm TiO2, from 8.49 ± 0.77 to 3.54 ± 0.34 mm−1 at about 110 min for AC with 60 nm TiO2, and from 8.61 ± 0.79 to 3.89 ± 0.41 mm−1 at about 128 min for AC with 100 nm TiO2, respectively. Spectral measurements confirm that the nanoparticles penetrate and accumulate in NC and AC. The results suggest that the penetration and accumulation of TiO2 nanoparticles have significant effects on the optical properties of NC and AC.

Efficacy of Proliferation of HeLa Cells under Three Different Low-Intensity Red Lasers Irradiation

This study was intended to compare the efficacy of proliferation of HeLa cells under three different low-intensity laser irradiation (LIL), that is, 633 nm, 658 nm, and 785 nm. The time-dependent responses of proliferation of HeLa cells after the red laser irradiation and the influence of fetal bovine serum (FBS) at 1%, 2%, 5%, or 10% on the proliferation of cells were also investigated. The results indicated that the proliferation of HeLa cells in 10% FBS was in proliferation-specific homeostasis (PSH) so that it was not modulated with LIL; the proliferation in FBS at 1%, 2%, or 5% was far from PSH so that it may be wavelength dependently modulated with LIL, and the maximum proliferation promotion was conducted with LIL at 633 nm amongst the three different LIL. It was concluded the wavelength-dependent photobiomodulation of LIL on proliferation of HeLa cells may be homeostatic.

In vitro study of the effects of ultrasound-mediated glycerol on optical attenuation of human normal and cancerous esophageal tissues with optical coherence tomography

Previous studies from our group have demonstrated that glucose solution can induce optical clearing enhancement of esophageal tissues with optical coherence tomography (OCT). The aims of this study were to evaluate the optical clearing effects of ultrasound-mediated optical clearing agents (OCAs) and to find more effective methods to distinguish human normal esophageal tissues (NE) and cancerous esophageal tissues (CE). Here we used the OCT technique to investigate the optical attenuation of NE and CE in vitro after treatment with 30% glycerol alone and glycerol combined with ultrasound, respectively. Experimental results showed that the averaged attenuation coefficient of CE was significantly larger than that of NE. The maximal decreases of averaged attenuation coefficients of NE and CE were approximately 48.7% and 36.2% after treatment with 30% glycerol alone, and they were significantly lower than those treated with 30% glycerol and ultrasound (57.5% in NE and 44.8% in CE). Moreover, after treatment with 30% glycerol alone, the averaged attenuation coefficients of NE and CE reached their minima in about 80 min and 65 min, respectively. The times were much shorter in NE and CE after treatment with glycerol with ultrasound, being about 62 min and 50 min, respectively. The results suggest that there is a significant difference in the optical properties of NE and CE, and that OCT with an ultrasound–OCAs combination has the ability to distinguish CE from NE.

Characterizing lamina propria of human gastric mucosa by multiphoton microscopy

Lamina propria (LP) of gastric mucosa plays an important role in progression of gastric cancer because of the site at where inflammatory reactions occur. Multiphoton imaging has been recently employed for microscopic examination of intact tissue. In this paper, using multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG), high resolution multiphoton microscopic images of lamina propria (LP) are obtained in normal human gastric mucosa at excitation wavelength ?ex = 800 nm. The main source of tissue TPEF originated from the cells of gastric glands, and loose connective tissue, collagen, produced SHG signals. Our results demonstrated that MPM can be effective for characterizing the microstructure of LP in human gastric mucosa. The findings will be helpful for diagnosing and staging early gastric cancer in the clinics.

Second harmonic generation imaging of dermal collagen component in human keloid tissue

In this paper, we report second harmonic generation (SHG) imaging of human keloid tissue. High resolution SHG images of collagen component were obtained in the superficial, medial and deep dermis of human keloid tissue, respectively. Our results show that this method has a capability to observe the structure of collagen component in human keloid tissue, which will help to better understand the formation process of human keloid scar at the molecular level.

Electroporation-assisted penetration of zinc oxide nanoparticles in ex vivo normal and cancerous human colon tissue

In this study, we presented the research of the penetration of zinc oxide nanoparticles (ZnO NPs) (30 and 90 nm), and electroporation (EP) assisted penetration of the ZnO NPs in the human normal colon (NC) and adenomatous colon (AC) tissues studied with optical coherence tomography (OCT) and diffuse reflectance (DR) measurement. The results have shown that the attenuation coefficient of colon tissue after the application of 30 or 90 nm ZnO NPs alone decreased approximately by 28% and 14% for NC tissue, 35% and 22% for AC tissue, respectively; while the attenuation coefficient of colon tissue after combined application of 30 or 90 nm ZnO NPs/EP decreased approximately by 46% and 30% for NC tissue, and 53% and 42% for AC tissue, respectively. The results illustrate EP can significantly increase the penetration of ZnO NPs in the colon tissue, especially in AC tissue. Through the analysis of attenuation coefficient and reflectance intensity of the colon tissue, we find that the accumulation of the ZnO NPs in the colon tissue greatly influenced the tissue optical properties.