acriflavine and Mouth-Neoplasms

Confocal laser endomicroscopy (CLE) is a technology that enables microscopic visualization of lesions in real-time (optical biopsy) and has been successfully applied for clinical use in gastroenterology. Recently, it was also introduced for head and neck squamous cell carcinoma (HNSCC) diagnostics. We previously designed a self-made CLE, which can provide bichrome images, with topical contrast agents that are safe for use in patients. Herein, we report findings of a pilot study using our self-made CLE to image pairs of normal and cancerous tissues. This study aimed to characterize the features of HNSCC compared with normal mucosa and to establish a methodology of in vivo real-time optical biopsy of HNSCCs.. HNSCC tissues were acquired from 10 patients who underwent surgical resection. Dissected specimens were first evaluated for their auto-fluorescence spectral profiles with 473 nm laser excitation and further optical observation. While obtaining the image, auto-fluorescence spectrum and intensity of the reflectance fluorescent signals were measured in real-time by a spectrometer. Subsequently, acriflavine was applied to the specimen to fluorescently label the nuclei and observe the difference between normal and cancerous tissues with 473 nm laser excitation. Finally, double staining with acriflavine and edible Food Red No.106 was performed to observe both nuclei and the cytoplasm of normal and cancerous tissues at 473 nm and 561 nm laser excitation.. Lower signals were detected from auto-fluorescence images of cancer tissues than normal tissues with 473 nm laser excitation. After acriflavine application, there was a clear difference between cancer and normal mucosa in the uniformity of nuclear size and shape. In normal mucosa, cells were arranged in an orderly manner, with each cell resembling a frog's egg. By contrast, in cancer tissues, the cell density was higher, and the cellular arrangement was less orderly. Using both acriflavine and Food Red No.106, images became more vivid, but more complicated because red dye staining of the cytoplasm emerged as fluorescence at different wavelengths.. Real-time in vivo imaging using the newly developed CLE and conditions may be used to distinguish cancer tissue from normal mucosa without invasive biopsy.

Topics: Acriflavine; Aged; Aged, 80 and over; Biopsy; Endoscopy; Female; Fluorescent Dyes; Head and Neck Neoplasms; Humans; Intravital Microscopy; Laryngeal Neoplasms; Male; Microscopy, Confocal; Middle Aged; Mouth Neoplasms; Optical Imaging; Pharyngeal Neoplasms; Pilot Projects; Squamous Cell Carcinoma of Head and Neck

Fibered confocal fluorescence microscopy (FCFM) allows in vivo investigation of pulmonary microstructures. However, the bronchial epithelium can only be imaged using exogenous fluorophores. The objective of this study is to compare methylene blue (MB) and acriflavine genotoxicity and to assess FCFM performance for in vivo imaging of precancerous lesions.. Genotoxicity was assessed using the comet assay on both cultured human lymphocytes and NCI-H460 cells, which had been exposed to MB or acriflavine before being illuminated at 660 or 488 nm, respectively. FCFM was performed on precancerous lesions in the hamster cheek pouch model, following topical application of the fluorophores. FCFM data were analyzed according to histology.. No genotoxicity was found using 0.01% (w/v) MB after illumination at 660 nm for 2 and 15 min (5 mW). Acriflavine exposure (0.025%) led to DNA damages, increasing from 2 to 15 min of light exposure at 448 nm in both lymphocytes (83.4 to 88%, p = 0.021) and NCI H460 cell populations (79.9 to 84.6%, p = 0.045). In total, 11 invasive carcinoma, 24 reserve cell hyperplasia, and 17 dysplasia lesions were imaged using FCFM in vivo. With both fluorophores, the cellular density increased from hyperplasia to high-grade dysplasia (p < 0.05). With MB, the cellular diameter significantly decreased (48.9 to 13.9 μm) from hyperplasia to carcinoma (p < 0.05). In this model, a cut-off diameter of 30 μm enabled the diagnosis of high-grade lesions with a sensitivity of 94.7% and a specificity of 97%.. Methylene blue can be used safely to image precancerous lesions in vivo. This study does not support the use of acriflavine in humans.

Topics: Acriflavine; Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Cells, Cultured; Comet Assay; Epithelial Cells; Fluorescent Dyes; Humans; Intravital Microscopy; Lung; Lymphocytes; Mesocricetus; Methylene Blue; Microscopy, Confocal; Microscopy, Fluorescence; Mouth Mucosa; Mouth Neoplasms; Mutagenicity Tests; Optical Imaging; Precancerous Conditions

We investigated the potential use of real-time confocal microscopy in the non-invasive detection of occult oral potentially malignant lesions. Our objectives were to select the best fluorescence contrast agent for cellular morphology enhancement, to build an atlas of confocal microscopic images of normal human oral mucosa, and to determine the accuracy of confocal microscopy to recognize oral high-grade dysplasia lesions on live human tissue.. Five clinically used fluorescent contrast agents were tested in vitro on cultured human cells and validated ex vivo on human oral mucosa. Images acquired ex vivo from normal and diseased human oral biopsies with bench-top fluorescent confocal microscope were compared to conventional histology. Image analyzer software was used as an adjunct tool to objectively compare high-grade dysplasia versus low-grade dysplasia and normal epithelium.. Acriflavine Hydrochloride provided the best cellular contrast by preferentially staining the nuclei of the epithelium. Using topical application of Acriflavine Hydrochloride followed by confocal microscopy, we could define morphological characteristics of each cellular layer of the normal human oral mucosa, building an atlas of histology-like images. Applying this technique to diseased oral tissue specimen, we were also able to accurately diagnose the presence of high-grade dysplasia through the increased cellularity and changes in nuclear morphological features. Objective measurement of cellular density by quantitative image analysis was a strong discriminant to differentiate between high-grade dysplasia and low-grade dysplasia lesions.. Pending clinical investigation, real-time confocal microscopy may become a useful adjunct to detect precancerous lesions that are at high risk of cancer progression, direct biopsy and delineate excision margins.

Topics: Acriflavine; Adult; Aged; Aged, 80 and over; Cell Line; Contrast Media; Female; Fluorescent Dyes; Humans; Male; Microscopy, Confocal; Middle Aged; Mouth Mucosa; Mouth Neoplasms

Confocal endomicroscopy is an emerging technique for intravital visualization of neoplastic lesions, but its use has so far been limited to the gastrointestinal (GI) tract. This study was designed to assess the feasibility of in vivo confocal endomicroscopy of different regions of the oropharyngeal mucosa and to evaluate different contrast agents. We examined five different regions of the human oropharynx in vivo, and images were collected in real time by using a confocal laser endoscope as formerly described for the GI tract. Additionally ex vivo specimens were examined using a topical contrast agent. Confocal scanning was performed at 488-nm illumination for excitation of exogenously applied fluorophores (topical acriflavine and intravenous fluorescein). Confocal endomicroscopy allowed for visualization of cellular and subcellular structures of the anterior human oropharyngeal region. Fluorescein staining yielded architectural details of the surface epithelium and also subepithelial layers. Images taken at increasing depth beneath the epithelium showed the mucosal capillary network. Acriflavine strongly contrasted the cell nuclei of the surface epithelium. The findings correlated well with the histology of biopsy specimens. This is the first report showing that the use of fluorescence confocal endomicroscopy represents a promising method to examine cellular details in vivo in different oropharyngeal regions in human.

Topics: Acriflavine; Adult; Biopsy; Capillaries; Carcinoma, Squamous Cell; Contrast Media; Endoscopes; Feasibility Studies; Female; Fluorescein; Humans; Male; Microscopy, Confocal; Mouth Mucosa; Mouth Neoplasms; Neoplasm Invasiveness; Oropharyngeal Neoplasms; Oropharynx; Sensitivity and Specificity; Video Recording