In vivo fibre optic confocal imaging of microvasculature and nerves in the rat vas deferens and colon

Papworth, Glenn D.; Delaney, Peter; Bussau, Lindsay; Vo, Liem T; King, Roger G

doi:10.1046/j.1469-7580.1998.19240489.x

Cited by 32 publications

(17 citation statements)

References 27 publications

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“…Fibre optic confocal imaging has been used to visualize a number of tissues in vivo . For example, it has been used to study the microvasculature of the rat colon and vas deferens 29 and the subsurface structure of hairless mouse skin 30 . The technique has also been used by us to visualize the rat liver sinusoidal bed in vivo.…”

Section: Discussionmentioning

confidence: 99%

Investigation of the effects of peppermint oil and valerian on rat liver and cultured human liver cells

Chan

King

2003

Clin Exp Pharma Physio

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1. The aim of the present study was to investigate the effects of peppermint oil and valerian on rat liver and cultured human hepatoma cells. 2. Rats received a single oral dose of peppermint oil (8.3-830 microL/kg) or valerian (0.31-18.6 g/kg), or daily oral doses of 83 microL/kg peppermint oil or 3.1 g/kg valerian for 28 days. After 24 h, rats were anaesthetized and measurements made of bile flow, liver function and in vivo sinusoidal area. Livers were then removed for histology. 3. Bile flow was unaffected by any treatment, except acute high-dose peppermint oil (830 microL/kg; 70% increase in flow). No change in liver enzyme activity was found, except for a 45% increase in alkaline phosphatase after chronic peppermint oil. No change in sinusoidal area in vivo or in histology was found following any treatment, although pretreatment with carbon tetrachloride reduced sinusoidal bed area and produced histological damage. Incubation of human hepatoma cells with 0.5 microL/mL (but not 0.05 microL/mL) peppermint oil or 20 mg/mL (but not 2 mg/mL) valerian resulted in increased cell death. 4. In conclusion, the present study demonstrated in vitro toxicity of high doses of valerian and peppermint oil in cultured human hepatoma cells and, at doses 2-3 orders of magnitude greater than those recommended for human use, an increase in rat bile flow after acute peppermint oil and an increase in alkaline phosphatase after chronic peppermint oil.

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Section: Discussionmentioning

confidence: 99%

Investigation of the effects of peppermint oil and valerian on rat liver and cultured human liver cells

Chan

King

2003

Clin Exp Pharma Physio

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“…Over the past decade, numerous efforts have been made to miniaturize confocal microscopes. [2][3][4][5][6][7] In order to achieve subcellular resolution with a conventional single-axis confocal microscope, a high numerical aperture ͑NA͒ is necessary, generally utilizing complex and bulky objectives lenses for diffraction-limited focusing of beams over a wide field of view. Geometrically, a high NA correlates to a short working distance for a given aperture size, thus limiting the depth at which subsurface imaging may be performed in tissue.…”

Section: Background and Introductionmentioning

confidence: 99%

Dual-axes confocal reflectance microscope for distinguishing colonic neoplasia

et al. 2006

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A dual-axes confocal reflectance microscope has been developed that utilizes a narrowband laser at 1310 nm to achieve high axial resolution, image contrast, field of view, and tissue penetration for distinguishing among normal, hyperplastic, and dysplastic colonic mucosa ex vivo. Light is collected off-axis using a low numerical aperture objective to obtain vertical image sections, with 4- to 5-microm resolution, at tissue depths up to 610 microm. Post-objective scanning enables a large field of view (610 x 640 microm), and balanced-heterodyne detection provides sensitivity to collect vertical sections at one frame per second. System optics are optimized to effectively reject out-of-focus scattered light without use of a low-coherence gate. This design is scalable to millimeter dimensions, and the results demonstrate the potential for a miniature instrument to detect precancerous tissues, and hence to perform in vivo histopathology.

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“…To achieve this level of performance, a conventional objectives with a large numerical aperture (NA) usually has a physical dimension on the centimeter scale. [2][3][4][5][6] The optics cannot easily be reduced to the millimeter dimensions necessary for imaging within the body without sacrificing resolution, field of view (FOV), or working distance (WD). Since a scanning mechanism is usually located between the laser source and the objective, elimination of aberrations often requires use of compound lenses to achieve high performance, thus further increasing the objective size.…”

Section: Introductionmentioning

confidence: 99%

Performance of dual axes confocal microscope for in vivo molecular and cellular imaging

et al. 2004

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The application of conventional confocal microscopes with high numerical aperture (NA) to in vivo imaging is limited by the objectiveís large physical dimensions and short working distance. We are developing a confocal microscope that uses simple low NA lenses oriented in a dual axes configuration for miniaturization and in vivo imaging. This architecture achieves a long working distance, micron level axial resolution, and reduced noise from scattered light outside the focal volume. Combined with the novel method of post-objective scanning, this design can be scaled down to millimeter dimensions. We derive the dual axes response from diffraction theory, and construct two tabletop prototypes to demonstrate the performance of this approach. We collect images from freshly excised biopsy specimens of human esophagus and transgenic mouse cerebellum expressing GFP. With horizontal cross-sectional images, we achieve 1 to 2 µm resolution and collect reflectance and fluorescence images. With vertical cross-sectional images, we achieve 4 to 5 µm resolution, dynamic range of 70 dB, and tissue penetration over 1 mm. An instrument miniaturized with this configuration could be used for in vivo cellular and molecular imaging.

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In vivo fibre optic confocal imaging of microvasculature and nerves in the rat vas deferens and colon

Cited by 32 publications

References 27 publications

Investigation of the effects of peppermint oil and valerian on rat liver and cultured human liver cells

Investigation of the effects of peppermint oil and valerian on rat liver and cultured human liver cells

Dual-axes confocal reflectance microscope for distinguishing colonic neoplasia

Performance of dual axes confocal microscope for in vivo molecular and cellular imaging

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