Liqin Zheng

Quantitatively linking collagen alteration and epithelial tumor progression by second harmonic generation microscopy

Collagen alteration is critical for epithelial tumor initiation and progression. Quantitatively linking collagen alteration and epithelial tumor progression is essential for developing an optical endoscopy to evaluate epithelial tumor progression. In this work, we established a quantitative link between collagen alteration and epithelial tumor progression using second harmonic generation (SHG) microscopy. It was found that SHG microscopy can provide quantitative features to effectively evaluate epithelial tumor progression, and to locate tumor and determine the margin of tumor regions. These results suggest that SHG microscopy has the potential in offering a noninvasive in vivo imaging tool to quantify epithelial tumor progression.

Multiphoton microscopy study of the morphological and quantity changes of collagen and elastic fiber components in keloid disease

Multiphoton microscopy was used to study the extracellular matrix of keloid at the molecular level without tissue fixation and staining. Direct imaging of collagen and elastin was achieved by second harmonic generation and two-photon excited fluorescence, respectively. The morphology and quantity of collagen and elastin in keloid were characterized and quantitatively analyzed in comparison to normal skin. The study demonstrated that in keloid, collagen content increased in both the upper dermis and the deep dermis, while elastin mostly showed up in the deep dermis and its quantity is higher compared to normal skin. This suggests the possibility that abnormal fibroblasts synthesized an excessive amount of collagen and elastin at the beginning of keloid formation, corresponding to the observed deep dermis, while after a certain time point, the abnormal fibroblast produced mostly collagen, corresponding to the observed upper dermis. The morphology of collagen and elastin in keloid was disrupted and presented different variations. In the deep dermis, elastic fibers showed node structure, while collagen showed obviously regular gaps between adjacent bundles. In the upper dermis, collagen bundles aligned in a preferred direction, while elastin showed as sparse irregular granules. This new molecular information provided fresh insight about the development process of keloid.

Depth-cumulated epithelial redox ratio and stromal collagen quantity as quantitative intrinsic indicators for differentiating normal, inflammatory, and dysplastic epithelial tissues

Multiphoton microscopy was used to isolate the intrinsic emission contribution of epithelial cellular origins and stromal collagen in normal, inflammatory, and dysplastic epithelial tissues, and quantify the depth-cumulated epithelial redox ratio and stromal collagen quantity. It was found that both inflammatory and dysplastic epithelial tissues display a large decrease in stromal collagen quantity but have very different epithelial redox ratio. These results suggest that probing differences in epithelial redox ratio in addition to stromal collagen quantity can serve as quantitative intrinsic indicators for differentiating normal, inflammatory, and dysplastic epithelial tissues.

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.

Multiphoton laser scanning microscopy of localized scleroderma.

Background/purpose: A real‐time, non‐invasive method will confer a benefit for the diagnosis and treatment of localized scleroderma (LS) in the clinic. The aim of this work was to demonstrate the potential of multiphoton laser scanning microscopy (MPLSM) for diagnosing LS and monitoring the treatment response in vivo.

Quantified characterization of human cutaneous normal scar using multiphoton microscopy.

The morphological alterations of human cutaneous normal scar were quantitatively analyzed using multiphoton microscopy (MPM) based on two-photon excited fluorescence and second harmonic generation. High-contrast, high-resolution images of normal scar and uninjured skin were obtained for comparison. In addition, some quantitative parameters have been extracted to quantitatively discriminate between normal scar and uninjured skin. The MPM combined with quantitative method enable a better understanding of microstructual alterations of the epidermis, elastic fiber, and collagen in normal scar. It may lead the way to making know the mechanism of normal scar formation and identifying feasible therapeutic options.

Multiphoton microscopic imaging of normal human rectum tissue.

In this paper, multiphoton microscopy (MPM), based on two-photon excited fluorescence and second harmonic generation signals, was used to image microstructures of human rectal mucosa and submucosa. The morphology and distribution of the main components in mucosa layer, goblet cells, intestinal glands, and a little collagen fibers have been clearly monitored, and the content and distribution of collagen, elastic fibers, and blood vessels in submucosa layer have also been distinctly obtained. The variation of these components is very relevant to the pathology in gastrointestinal system, especially early rectal cancer. Our results indicate that the MPM technique has the potential application in vivo in the clinical diagnosis and monitoring of early rectal cancer.

Characteristics of scar margin dynamic with time based on multiphoton microscopy

Scar margins dynamic with time were quantitatively characterized using multiphoton microscopy (MPM). 2D large-area and 3D focused images of elastin and collagen at scar margins were obtained to extract quantitative parameters. An obvious boundary was observed at the scar margin, showing altered morphological patterns of elastin and collagen on both sides. Content alteration of elastin and collagen between the two sides of boundary were defined to characterize scar margins from different individuals. The statistical results from 15 normal scar samples strongly demonstrated that content alteration degree of elastin and collagen had decreasing tendency with the increase of patient age or scar duration, consistent with the fact of normal scars regressing spontaneously over time. It indicated that alteration degree can potentially serve as quantitative indicators to examine wound healing and scar progression over time. With the advent of clinical portable multiphoton endoscopes, the MPM technique can be applied in tracking scar formation and progression in vivo by examination of scar margin.

Quantification of scar margin in keloid different from atrophic scar by multiphoton microscopic imaging.

Multiphoton microscopy (MPM) was applied to examine the marginal region at dermis of keloid compared with atrophic scar. High-resolution large-area image showed an obvious boundary at the scar margin and different morphological patterns of elastin and collagen on the two sides, further visualized by the focused three-dimensional images. Content alteration of elastin or collagen between the two sides of boundary was quantified to show significant difference between keloid and atrophic scar. Owing to the raised property of keloid with overproduced collagen on the scar side, the content alteration was positive for elastin and negative for collagen. On the contrary, the content alteration was negative for elastin and positive for collagen in the atrophic scar case due to the atrophic collagen on the scar side. It indicated that examination of the scar margin by MPM may lead a new way to discriminate different types of scars and better understand the scarring mechanisms.

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.