A photochemical method for in vitro evaluation of fluid flow in human dentine

Objective

To evaluate the flow dynamics of dentine fluid using a chemiluminescence method in vitro.

Materials and methods

Horizontally sliced coronal dentine specimens with thicknesses of 1.4, 1.6, 1.8, and 2.0 mm (n = 10 each) were prepared from extracted human third molars. After cleaning with EDTA, a mounted specimen was clamped between 2 acrylic chambers attached to both the occlusal and pulpal sides. The occlusal chamber, which was closed with a glass coverslip, was filled with a chemiluminescent solution (0.02% luminol and 1% sodium hydroxide in water). A trigger solution of 1% hydrogen peroxide and 1% potassium ferricyanide was injected into the pulpal chamber at a constant pressure of 2.5 kPa, and allowed to immediately flow into the patent dentinal tubules. Four consecutive measurements (T1–T4) were performed on each sample by recording the emission of chemiluminescence with a photodetector. The relationship between the crossing time of the liquid through the slice and dentine thickness was examined.

Results

An apparent time delay was detected between the starting points of the trigger solution run and photochemical emission at T1. Dt (Dt, s) values of each thickness group were 13.6 ± 4.25 for 1.4 mm, 18.1 ± 2.38 for 1.6 mm, 28.0 ± 2.46 for 1.8 mm, and 39.2 ± 8.61 for 2.0 mm, respectively. Dt significantly decreased as dentine became thinner towards the pulp chamber (P < 0.001).

Conclusions

The velocity of fluid flow increased both with increasing dentine depth or reduction of remaining dentine thickness.     

Variations in the preoperative resources use and the practice pattern in Japanese cholecystectomy patients

Purpose  

There are several preoperative treatment options, such as the staged bile duct intervention (BDI), for the successful completion of a cholecystectomy, regardless of the use of an open cholecystectomy (OC) or a laparoscopic cholecystectomy (LC). However, few studies have investigated how the characteristics of the patient or the hospital affect the preoperative resource use. This study determined the factors, including the hospital characteristics, associated with the preoperative resource utilization or with the treatment process.     

A case of small cell carcinoma of the kidney

A 47-year-old man had a retroperitoneal tumor measuring 18 cm in maximum diameter of the left kidney that was diagnosed with computed tomography (CT)-guided needle biopsy as small cell carcinoma. Microscopically, the tumor cells showed immunohistochemical reaction for neural cell adhesion molecule antibodies. This patient with advanced renal small cell carcinoma and multiple metastatic lesions was treated with the first-line combination chemotherapy of cisplatin, etoposide and ifosphamide, which showed a partial response of primary renal tumor and a complete response of liver metastasis, and with the second-line chemotherapy of cisplatin and irinotecan, which showed a complete response of Virchow's nodal metastasis. Thereafter, in spite of salvage chemotherapy of amurubicin hydrochloride for persistent and refractory renal small cell carcinoma, he died 32 months after the first presentation due to local progression. However, combination chemotherapy of these anticancer agents made his prognosis more favorable than we expected before treatment. The extrapulmonary small cell carcinomas are generally known to be more aggressive and malignant than the lung small cell carcinomas, and small cell carcinoma arising from the kidney is an extremely rare malignant neoplasm, with only 34 cases reported in the English or Japanese literature. The prognosis of renal small cell carcinomas is currently limited as compared with the lung small cell carcinomas, and therefore a cumulative investigation of a larger number of cases treated with multidisciplinary modalities including combination chemotherapy is necessary.     

A case of neobladder-cutaneo fistula after cystectomy

A 69-year-old man was admitted for the treatment of muscle-invasive bladder carcinoma. Total cystectomy was performed and an ileal neobladder was constructed by a modification of Studer's method. However, a week later, a subcutaneous abscess occurred withwound dehiscence. Open drainage and wound debridement was carried out. Three weeks later, a neoblader-cutaneous fistula was seen on cystography. We managed it conservatively by means of wound debridement and washing with physiological saline. The fistula was closed on the 95th day after operation. The patient can now pass urine by himself.     

Schwannoma arising from the urinary bladder wall: a case report

A 50-year-old woman visited our department for further examination of incidental bladder tumor detected by ultrasound at her health check. Cystoscopy demonstrated a submucosal tumor in the anterior wall of the urinary bladder. Magnetic resonance imaging revealed that the tumor had high intensity in T2- weighted images. The slightly-elevated serum level of dopamine and uptake image in the meta iodobenzyl granidine-scintigraphy test suggested that she might have ectopic pheochromocytoma in the urinary bladder. Partial cystectomy with extirpation of the tumor was performed. The histological diagnosis was schwannoma, which is rarely found in the urinary bladder.     

Cell proliferation activity and the expression of cell cycle regulatory proteins in oral lichen planus

BACKGROUND: In oral lichen planus (OLP), destruction of the basal cell layer, which is one of the characteristic histological features, is seen and many changes in cell proliferation, cell repair and cell death occur in the injured mucosal epithelium. METHODS: We studied mucosal tissues from 19 patients of OLP and 10 controls, with immunohistochemistry for Ki-67, p53, cyclin dependent kinase inhibitors (CDKI) and cyclins. Mitotic count was calculated. TUNEL assay was also performed for evaluation of apoptotic cell death. RESULTS: Mitotic count, Ki-67 and cyclin D1 labeling indices in the basal and parabasal layers of OLP mucosa were elevated in comparison with those of controls. p53, p21Cip1 and TUNEL indices of OLP mucosa were also increased. CONCLUSIONS: These complex changes, which concomitantly occur in the injured mucosal epithelium, could contribute to the development and maintenance of characteristic mucosal epithelial architectures seen in OLP.     

Species-related differences in inotropic effects of angiotensin II in mammalian ventricular muscle: receptors, subtypes and phosphoinositide hydrolysis.

1. Experiments were carried out to clarify the mechanisms responsible for variations in the positive inotropic effect (PIE) of angiotensin II (AII) on ventricular muscles from various mammals. We examined the density of AII receptors, the relative proportions of receptor subtypes and the acceleration of the hydrolysis of phosphoinositide that was induced by AII, as well as the PIE of AII in ventricular muscles from the rabbit, dog, rat and ferret. 2. In the rabbit, AII (1 microM) in the presence of bupranolol (0.3 microM) and prazosin (0.1 microM) elicited a concentration-dependent PIE, which was antagonized by a selective AT1 subtype antagonist, losartan, but not by an AT2 antagonist, PD123319. AII did not have any inotropic effects in ventricular muscles from the dog, rat and ferret. 3. Specific high-affinity binding of [125I]-AII, with a similar Kd value in each case (1-2 nM), was observed with membrane fractions derived from ventricular muscle of all four species tested. 4. In the rabbit, losartan and PD123319 each displaced approximately 50% of [125I]-AII specific binding having high affinity for the receptors, and indicating that AT1 and AT2 subtypes were present in equal numbers. In the other species the AT1 subtype of receptors was predominant. 5. In all four species AII caused a concentration-dependent acceleration of the hydrolysis of phosphoinositide in ventricular slices that had been prelabelled with myo-[3H]-inositol. 6. The results indicate that the signal-transduction process distal to acceleration of the hydrolysis of phosphoinositide may be responsible for the wide range of species variations in the inotropic action of AII on mammalian ventricular myocardium.