The upper airways play important roles in respiratory defensive reflexes. Although solitary chemosensory cells and chemosensory cell clusters have been reported in the laryngeal mucosa of mammalian species, the distribution and cellular morphology of chemosensory cells remain unclear. In the present study, the distribution and morphology of solitary chemosensory cells and chemosensory cell clusters were examined by immunofluorescence for GNAT3 on whole‐mount preparations of the rat laryngeal mucosa. Electrophysiological experiments were performed to analyze the respiratory reflexes evoked by bitter stimuli to the laryngeal cavity. In the whole area of the laryngeal mucosa, the numbers of GNAT3‐immunoreactive solitary chemosensory cells and chemosensory clusters were 421.0 ± 20.3 and 62.7 ± 6.9, respectively. GNAT3‐immunoreactive solitary chemosensory cells were mainly distributed in the mucosa overlying epiglottic and arytenoid cartilage, and chemosensory clusters were mainly distributed on the edge of the epiglottis and aryepiglottic fold. GNAT3‐immunoreactive solitary chemosensory cells were slender with elongated processes or had a flask‐like/columnar shape. The number of GNAT3‐immunoreactive cells in chemosensory clusters was 6.1 ± 0.4, ranging between 2 and 14 cells. GNAT3‐immunoreactive cells in the cluster were variform and the tips of apical processes gathered at one point at the surface of the epithelium. The tips of apical cytoplasmic processes in solitary chemosensory cells and cells in the cluster were immunoreactive for espin, and faced the laryngeal cavity. Physiological experiments showed that the application of 10 mm quinine hydrochloride to the laryngeal cavity decreased respiratory frequency. The present results revealed the chemosensory field of the larynx and the morphological characteristics of the laryngeal chemosensory system for respiratory depression.

Background: Screening for coronary artery disease (CAD) at the initiation of dialysis is a K/DOQI recommendation. However, it remains unclear when screening for CAD should be repeated in patients without significant disease at the time of starting dialysis. The objectives of this study were to determine: (1) the survival of hemodialysis (HD) patients without CAD at the initiation of dialysis, (2) the major predictors of CAD events, and (3) the best time to repeat screening for CAD after the initiation of HD. Methods: In order to assess the occurrence of de novo major adverse cardiac events (MACE) in HD patients without CAD, we prospectively followed patients who were normal according to screening tests for CAD performed at the initiation of HD. To detect CAD, 177 of 305 new HD patients underwent coronary angiography and/or pharmacologic stress thallium-201 single photon emission computed tomography within 1 month after starting HD. Among these 177 patients, 100 did not have significant CAD and they were followed for a median of 24 months. Results: Five MACE occurred during follow-up, but no events were observed within 1 year after starting HD. All 5 events occurred during the second year of HD (two events occurred immediately after the end of the first year). An increased level of C-reactive protein (CRP) was the only independent predictor of MACE (hazard ratio: 1.39; 95% CI: 1.03–1.78, p = 0.008) according to Cox regression analysis. The optimum cut-off value of CRP for predicting MACE was 3.5 mg/l. The MACE-free rate at 2 years (99 vs. 79%, p = 0.0008) was significantly higher in patients with a CRP level (3.5 mg/l than in those with a level <3.5 mg/l). Conclusion: One year after the initiation of HD could be the optimum time to repeat screening for CAD in patients without disease at the initiation of HD. If the serum CRP level is less than 3.5 mg/l, postponing repeat screening for CAD could be considered.

Early identification of leukoplakic oral squamous cell carcinoma (OSCC) is difficult. The purpose of this study was to determine whether it was possible to detect change from normal epithelium to leukoplakic OSCC using a fluorescence visualization (FV) device in a 4-nitroquinoline 1-oxide (4NQO) -induced rat tongue cancer model. If successful, this would facilitate early detection of OSCC. The rats (3 groups of 5) were administered 50 ppm 4NQO in their drinking water over a period of 10, 15, or 20 weeks. Five nontreated rats were used as a control group. Images of their tongues obtained by FV were analyzed for change in fluorescence intensity (FI) using image analysis software. Immunoreaction for anti-CK13, anti-CK17, and anti-E-cadherin antibodies was also histopathologically evaluated. Receiver operating characteristic (ROC) analysis was used to calculate the cut-off values, sensitivity, specificity, and area under the curve. The most marked change in FI was found between the control and 10-week groups, with an increase observed in its average value and range in the latter. These findings differed from those characteristic of leukoplakia. No significant difference was observed in the positive cell rate for immunoreaction for anti-CK13 or anti-CK17 antibodies between the control and 10-week groups. A significant decrease was observed in the positive pixel ratio of immunoreaction for anti-E-cadherin antibody in the 10-week group in comparison with in the control group (p <0.05). These results showed that disruption of intercellular adhesion could be observed at 10 weeks. In the ROC analysis, the FI cut-off value in the 10-week and control groups was 51.9, sensitivity 95.5%, and specificity 96.9%. This indicated that normal epithelium could be accurately distinguished from low-grade dysplasia with high probability. These results demonstrate that analysis of change in FI as measured by FV could facilitate early detection of leukoplakic OSCC.