Single Transition Layer in Mass-Conserving Reaction-Diffusion Systems with Bistable Nonlinearity

Mass-conserving reaction-diffusion systems with bistable nonlinearity are useful models for studying cell polarity formation, which is a key process in cell division and differentiation. We show the existence and stability of stationary solutions with a single internal transition layer in such reaction-diffusion systems under general assumptions by the singular perturbation theory.Comment: 35 pages, 2 figure

Histopathological Change of Oral Malignant Tumour and Epithelial Dysplasia Subjected to Photodynamic Therapy

Objectives: The purpose of this study is to analyze the morphological change of cell nuclei and the change of proliferating activity of oral malignancy and epithelial dysplasia between before and after photodynamic therapy in order to predict recurrence.Material and Methods: We experienced 14 cases of oral squamous cell carcinoma, one case of verrucous carcinoma and seven cases of epithelial dysplasia treated by photodynamic therapy (PDT). The mean nuclear area (NA) and coefficient of variation of the nuclear area (NACV) of 100 nuclei per slide were calculated using computer-assisted image analysis in hematoxylin and eosin stained biopsy specimens before and after PDT. Additionally, proliferating cell nuclear antigen (PCNA) immunohistochemistry was carried out in each specimen.Results: The mean NA after PDT was significantly lower than that before PDT in the nonrecurrent group. However, there was no significant difference in mean NA before and after PDT in the recurrent group. There were no significance differences in NACV before and after PDT in either the nonrecurrent or recurrent group. Furthermore, the PCNA labelling indices of the specimens after PDT was significantly lower than that before PDT in both the nonrecurrent and the recurrent group.Conclusions: Mean nuclear area in the biopsy specimen after photodynamic therapy is likely to be a predictive marker for the recurrence of oral squamous cell carcinoma or epithelial dysplasia subjected to photodynamic therapy, while coefficient of variation of the nuclear area and proliferating cell nuclear antigen labelling indices are less helpful in predicting the recurrence of such lesions

Laparoscopic Bladder-Preserving Surgery for Enterovesical Fistula Complicated with Benign Gastrointestinal Disease

Enterovesical fistula (EVF) is a relatively uncommon condition that is associated with severe morbidity. Minimally invasive and organ-preserving surgery should be performed in the case of EVF caused by benign diseases. We applied laparoscopic bladder-preserving surgery (LBPS) for EVF caused by benign gastrointestinal disease. Here, we report a surgical technique for LBPS. Patient and instrument port positioning are similar to those used in laparoscopic colorectal surgery. Dissection around the fistula is performed along the intestine as distant from the bladder as possible. If there is sufficient area around the intestinal portion of the fistula, it is isolated and resected using a linear stapler. If this approach is not possible, the intestinal fistula is sharply dissected as far away from the bladder as possible. LBPS for EVF was performed in 4 patients and included 3 direct sharp dissections and 1 stapling dissection. Three of the 4 patients did not require any further treatment for the bladder, and all procedures were feasibly accomplished under laparoscopic conditions. In conclusion, LBPS is feasible in cases of EVF caused by benign gastrointestinal disease, and we suggest that it should be the first choice of intervention in such cases

A Comparative Study between CT and Histopathologic Findings of Amyloid Goiter

There are only a few reports describing the imaging features of amyloid goiter with adequate histopathologic correlation. We present a case of amyloid goiter, focusing the correlation between CT and autopsy specimen findings. CT showed diffuse low attenuation areas (40-50 H.U. ) which corresponded to the tissue with dense amyloid deposits. There was also focal areas of very low attenuation which contained the adipose tissue. The latter finding is relatively characteristic for amyloid goiter, because fatty infiltration is known to be frequently associated with amyloid goiter : a rare finding in other disorders