A novel method for assessing bladder-related pain reveals the involvement of nerve growth factor in pain associated with cyclophosphamide-induced chronic cystitis in mice.

BACKGROUND: Pain is a prominent feature of interstitial cystitis/painful bladder syndrome (IC/PBS), but the underlying mechanisms are not fully understood. There is a lack of well-characterized research tools, such as pain evaluation methods and experimental animal models, for investigating non-ulcerative cystitis. We developed a novel method for evaluating bladder pain in mice with cyclophosphamide (CYP)-induced cystitis. METHODS: Cystitis was produced by a single intraperitoneal injection of CYP (300 mg/kg) or repeated injections of CYP (150 mg/kg once daily for 4 days). Blunt stimulation with a cotton probe was applied to the abdominal region, and the thresholds for withdrawal responses were measured quantitatively using an anaesthesiometer. RESULTS: The single injection of CYP provoked acute cystitis with severe bladder inflammation in mice. In these mice, we could detect an increased sensitivity to blunt stimulation, which was abolished by intravesical lidocaine. The stimulation induced phosphorylation of extracellular signal-regulated kinases in bladder-projecting sensory neurons. Chronic treatment with CYP produced persistent pain responses to the blunt stimulus. Although there were few signs of bladder inflammation in these mice, the concentration of nerve growth factor (NGF) was elevated in bladder tissue, and NGF antiserum inhibited the hypersensitivity. CONCLUSIONS: The blunt probe method is useful for evaluating bladder pain signalling in mice, and revealed the involvement of an NGF-sensitive pain pathway in chronic cystitis pain. This assessment method may be useful for studying the pathophysiology of bladder pain and for developing therapeutic strategies for non-ulcerative IC/PBS in patients.

Tooth shape reconstruction from dental CT images with the region-growing method.

OBJECTIVES: The three-dimensional shape information of teeth provides useful information. However, obtaining accurate three-dimensional shapes of teeth is difficult without extracting them physically. In this study, we aimed to develop a method for automatically extracting accurate three-dimensional shapes of teeth from dental CT images. METHODS: The proposed method includes pre-processing and region extraction. Pre-processing is a combination of image-processing techniques that enhances tooth regions. In the region-extraction process, the region-growing method is introduced for extracting a region of each tooth. Constraint conditions determined by considering the characteristics of the structure of teeth are introduced for accurate extraction. Finally, morphological image processing is applied for eliminating discontinuous points. RESULTS: We carried out an experiment in which the three-dimensional shapes of teeth were reconstructed from dental CT images. Quantitative evaluation was performed by measuring the three-dimensional spatial accordance rates between the region obtained by the proposed method and the manually extracted region. The proposed method was significantly more accurate than an existing method at the 5% level. CONCLUSIONS: The experimental results showed that the proposed method reconstructs the shapes of teeth with high precision. However, an unextracted region remained at the surface of the enamel. Solving this problem and improving the extraction accuracy are important topics for future work.

[Silicon of the medium in the postoperative maxillary cyst].

As part of a study on chronic inflammatory disease of the mucous membrane, silicon of the medium in postoperative maxillary cysts and in other cysts was measured, and following results were obtained. Silicon concentrations of the medium in the postoperative maxillary cysts and in the postoperative ethmoidal cysts were 34.5 ppm and 42.9 ppm (geometrical mean) respectively, and they were higher than in other primary cysts such as frontal cyst, nasal vestibular cyst, and dental cyst. The silicon content of the medium in the postoperative maxillary cyst varied with the water content of the medium; the lower the water content the higher was the silicon content and the relationship was expressed by the following equation. log S = 7.43 + 7.14 log d-6.14 log w, where S = Si (mcg), d = dry weight (g.) and w = wet weight (g.). The high concentration of silicon in the postoperative cyst was considered to be due to the large amount of silicon transudate from the surrounding fibrous tissue through a highly damaged or missing epithelial wall of the cyst.

Dermoid cyst of the auricle: report of two cases.

Dermoid cyst of the auricle is a very rare lesion in Japan. The cysts studied for this report demonstrated a benign clinical course with a tendency to become larger. The clinical and pathological characteristics of these cysts are reviewed.