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Pouch Model (pouch + model)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

The Anti-Inflammatory Effect of Bee Venom Stimulation in a Mouse Air Pouch Model Is Mediated by Adrenal Medullary Activity

JOURNAL OF NEUROENDOCRINOLOGY, Issue 1 2003
Y.-B. Kwon
Abstract Cutaneous electrical or chemical stimulation can produce an anti-inflammatory effect, which is dependent on adrenal medullary-sympathetic activation. We have previously shown that peripheral injection of bee venom (BV) also produces a significant anti-inflammatory effect that is neurally mediated. In the present study, we examined whether this anti-inflammatory effect is also dependent on the adrenal gland using the mouse inflammatory air pouch model. Subcutaneous (s.c.) BV injection produced a marked suppression of leucocyte migration and tumour necrosis factor (TNF)- , concentration induced by zymosan injection into the air pouch. The role of the adrenal gland in this suppression was evaluated in adrenalectomized mice. Adrenalectomy significantly reversed the suppression of leucocyte migration and TNF- , elevation caused by BV. Serum concentrations of corticosteroid were increased in mice with zymosan-induced air-pouch inflammation and this increase was reduced by BV administration, suggesting that adrenal corticosteroid release is not involved in mediating the anti-inflammatory effects of BV. To test this hypothesis, the corticosteroid receptor antagonist (RU486) was administered and found not to affect the BV-induced inhibition of leucocyte migration. By contrast, pretreatment with the , -adrenergic antagonist propranolol reversed the BV-induced inhibitory effect on leucocyte migration. These results suggest that the anti-inflammatory effect of s.c. BV administration is mediated in part by the release of catecholamines from the adrenal medulla. [source]

Evaluation of the Photosensitizer Tookad® for Photodynamic Therapy on the Syrian Golden Hamster Cheek Pouch Model: Light Dose, Drug Dose and Drug,light Interval Effects,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2003
François Borle
ABSTRACT We have evaluated the efficacy of the new photosensitizer (PS) Tookad® in photodynamic therapy (PDT) in vivo. This PS is a palladium-bacteriopheophorbide presenting absorption peaks at 762 and 538 nm. The light dose, drug dose and drug injection,light irradiation interval (DLI), ranging between 100 and 300 J/cm2, 1 and 5 mg/kg and from 10 to 240 min, respectively, were varied, and the response to PDT was analyzed by staging the macroscopic response and by the histological examination of the sections of the irradiated cheek pouch. The level of PDT response, macroscopically and histologically, shows a strong dependence on the DLI, light dose and drug dose at the applied conditions in the normal hamster cheek pouch. A decay of the tissular response with increasing DLI is observed corresponding to a time of half-maximum response ranging from 10 to 120 min, depending on drug dose and light dose. The tissues affected at the lowest doses are predominantly the vascularized diffuse connective tissue situated between the inner and outer striated muscle (SM) layers as well as these muscle layers themselves. The highest response at the shortest DLI and the absence of a measurable response at DLI longer than 240 min at 300 J/cm2 and drug dose of 5 mg/kg are characteristics of a predominantly vascular effect of this PS. This observation suggests that Tookad® could be effective in PDT of vascularized lesions or pathologies associated with the proliferation of neovessels. [source]

Dual-mode reflectance and fluorescence near-video-rate confocal microscope for architectural, morphological and molecular imaging of tissue

JOURNAL OF MICROSCOPY, Issue 1 2007
ALICIA L. CARLSON
Summary We have developed a near-video-rate dual-mode reflectance and fluorescence confocal microscope for the purpose of imaging ex vivo human specimens and in vivo animal models. The dual-mode confocal microscope (DCM) has light sources at 488, 664 and 784 nm, a frame rate of 15 frames per second, a maximum field of view of 300 × 250 ,m and a resolution limit of 0.31 ,m laterally and 1.37 ,m axially. The DCM can image tissue architecture and cellular morphology, as well as molecular properties of tissue, using reflective and fluorescent molecular-specific optical contrast agents. Images acquired with the DCM demonstrate that the system has the sub-cellular resolution needed to visualize the morphological and molecular changes associated with cancer progression and has the capability to image animal models of disease in vivo. In the hamster cheek pouch model of oral carcinogenesis, the DCM was used to image the epithelium and stroma of the cheek pouch; blood flow was visible and areas of dysplasia could be distinguished from normal epithelium using 6% acetic acid contrast. In human oral cavity tissue slices, DCM reflectance images showed an increase in the nuclear-to-cytoplasmic ratio and density of nuclei in neoplastic tissues as compared to normal tissue. After labelling tissue slices with fluorescent contrast agents targeting the epidermal growth factor receptor, an increase in epidermal growth factor receptor expression was detected in cancerous tissue as compared to normal tissue. The combination of reflectance and fluorescence imaging in a single system allowed imaging of two different parameters involved in neoplastic progression, providing information about both the morphological and molecular expression changes that occur with cancer progression. The dual-mode imaging capabilities of the DCM allow investigation of both morphological changes as well as molecular changes that occur in disease processes. Analyzing both factors simultaneously may be advantageous when trying to detect and diagnose disease. The DCM's high resolution and near-video-rate image acquisition and the growing inventory of molecular-specific contrast agents and disease-specific molecular markers holds significant promise for in vivo studies of disease processes such as carcinogenesis. [source]

The Anti-Inflammatory Effect of Bee Venom Stimulation in a Mouse Air Pouch Model Is Mediated by Adrenal Medullary Activity

Effects of low-level laser therapy on collagen expression and neutrophil infiltrate in 5-fluorouracil-induced oral mucositis in hamsters

LASERS IN SURGERY AND MEDICINE, Issue 6 2010
Nilza Nelly Fontana Lopes DDS
Abstract Background and Objectives Several studies have suggested that low-level laser therapy (LLLT) can ameliorate oral mucositis; however, the mechanisms involved are not well understood. The aim of this study was to investigate the mechanisms of action of LLLT on chemotherapy-induced oral mucositis, as related to effects on collagen expression and inflammation. Materials and Methods A hamster cheek pouch model of oral mucositis was used with all animals receiving intraperitoneal 5-fluorouracil, followed by surface irritation. Animals were randomly allocated into three groups, and treated with an InGaAIP diode laser at a wavelength of 660,nm and output power of 35 or 100,mW laser, or no laser. Clinical severity of mucositis was assessed at four time-points by a blinded examiner. Buccal pouch tissue was harvested from a subgroup of animals in each group at four time-points. Collagen was qualitatively and quantitatively evaluated after picrosirius staining. The density of the neutrophil infiltrate was also scored. Results Peak clinical severity of mucositis was reduced in the 35,mW laser group as compared to the 100,mW and control groups. The reduced peak clinical severity of mucositis in the 35,mW laser group was accompanied by a decrease in the number of neutrophils and an increase in the proportion of mature collagen as compared to the other two groups. The total quantity of collagen was significantly higher in the control (no laser) group at the day 11 time-point, as compared to the 35,mW laser group, consistent with a more prolonged inflammatory response in the control group. Conclusion This study supports two mechanisms of action for LLLT in reducing mucositis severity. The increase in collagen organization in response to the 35,mW laser indicates that LLLT promotes wound healing. In addition, LLLT also appears to have an anti-inflammatory effect, as evidenced by the reduction in neutrophil infiltrate. Lasers Surg. Med. 42:546,552, 2010. © 2010 Wiley,Liss, Inc. [source]