Terumichi Fujikura

Histochemical and functional characteristics of metachromatic cells in the nasal epithelium in allergic rhinitis: Studies of nasal scrapings and their dispersed cells

BACKGROUND In allergic rhinitis, metachromatic cells in the nasal epithelium increase in number and are thought to play an important role in nasal allergic manifestation. METHODS To determine immunohistochemical and functional characteristics of the metachromatic cells, nasal scrapings and their dispersed cells from patients with perennial allergic rhinitis were studied. RESULTS Eighty-three percent of all metachromatic cells in dispersed cell preparations were tryptase-positive mast cells (MCT), 10% were tryptase-chymase-positive cells (MCTC), and 7% were negative (n = 10). The mean histamine chymase-positive cells (MCTC), and 7% were negative (n = 10). The mean histamine content per metachromatic cell was 1.9 +/- 2 pg. The histamine content and histamine release from nasal surface scrapings of patients sensitized with mite antigen were strongly correlated with the level of serum IgE antibody for mite antigen. The net histamine release from nasal scraping was antigen-dose-dependent (1:2 x 10(7) to 1:2 x 10(3) dilution), and the antigen stimulated release of up to 17% of cell-associated histamine within 5 to 7 minutes. Histamine release from nasal scrapings induced by calcium ionophore A23187 was up to 21% of cell-associated histamine within 2 to 4 minutes, but no histamine release was stimulated by compound 48/80, substance P, or poly-L-lysine. Histamine release from nasal scrapings was inhibited 46% (10(-5) mol/L) to 96% (10(-4) mol/L) by quercetin and 58% (10(-4) mol/L) to 72% (10(-3) mol/L) by sodium cromoglycate. CONCLUSIONS These findings show the predominant characteristics of mast cells in the nasal epithelium in allergic rhinitis, and this information may be useful in relation to a therapeutic approach.

Mast cell quantitation in nasal polyps, sinus mucosa and nasal turbinate mucosa

The distribution and abundance of mast cells in nasal polyps, the maxillary sinus mucosa of patients with sinusitis and the turbinate mucosa of allergic rhinitis was microscopically examined using different methods of fixation. In the epithelium of the surface and the ducts of nasal polyps (n = 8), the mean number of mast cells was over 20,000 per mm3 using Motas fixation and the increase was correlated with the epithelial thickness (P < 0.05). On the other hand those of the maxillary sinus mucosa (n = 6) and the nasal turbinate mucosa (n = 7) were less than 6,000 per mm3. In the subepithelial layer or areas deeper than the area with the glands, however, mast cell counts were less than 3,200 per mm3 in all diseases. More than 70-90 per cent of all mast cells in the epithelium of the mucosal surface and the ducts of the polyp, the maxillary sinus mucosa and nasal turbinates were formalin sensitive. Most of the mast cells in the subepithelial and deeper areas were formalin resistant in all diseases. These results suggest that conditions for mast cell growth differ between polyps and the other diseases, and that the conditions which affect mast cells may contribute to polyp development.

Adrenomedullin level in the nasal discharge from allergic rhinitis cohort

Adrenomedullin (AM) is a potent hypotensive and vasodilatory peptide. AM may exert protective actions against the development of many diseases by modulating the blood circulation and body fluid balance. In addition to these functions, it has recently been reported to play important roles in the development of allergy and infections. The purpose of the present study was to demonstrate the existence of AM in the human nasal mucosa and to discuss whether AM might contribute to the pathogenesis of nasal congestion. We measured the total AM concentrations in the nasal discharge. The total AM concentration in the nasal discharge was significantly higher in the non-allergy group (72.1 ± 55.5 fmol/ml) than in the allergy group (37.1 ± 44.2 fmol/ml). By immunohistochemical examination, we identified AM-containing cells in the nasal mucosa from both subjects with and without nasal allergy, and also in nasal polyps. Moreover, those cells were positive for anti-tryptase antibody which recognizes mast cells. In nasal allergy, vasodilatation and increase in vascular permeability are characteristic features of the immediate phase response. Reduced AM levels in the nasal discharge may be associated with attenuation of both of these factors. On the other hand, immunohistochemical analysis demonstrated AM-immunoreactive cells in the chronic phase of rhinosinusitis. In the late and inflammatory phase, mast cells produce AM, which possibly acts as an inhibitor of inflammatory cell migration. In conclusion, AM may be actively secreted into the nasal discharge. AM in the nasal discharge may have protective and anti-inflammatory effects in the nasal mucosa.

Laparoscopic skill improvement after virtual reality simulator training in medical students as assessed by augmented reality simulator.

Definitive assessment of laparoscopic skill improvement after virtual reality simulator training is best obtained during an actual operation. However, this is impossible in medical students. Therefore, we developed an alternative assessment technique using an augmented reality simulator.

Clinical application of virtual endoscopy as a support system for endoscopic sinus surgery

Conclusions: Computer processing of conventional CT images can provide virtual endoscopic images (VEIs). Surgeons observing these images feel as if they are observing the lesion using an endoscope. Simulation based on animated VEIs before endoscopic sinus surgery (ESS) is useful for the improvement of surgical safety and surgeons’ education. Although the production of VEIs requires certain surgical experience, after the production of VEIs, surgeons can repeat simulation of a surgical procedure and have confidence in the actual operation. Objective: We investigated the clinical application of CT-reconstructed VEIs as a support system for ESS. Materials and methods: A GE Light Speed Ultra 16 as a 16-slice CT scanner and Advantage Workstation 4.2 were used. Software called Navigator in this workstation allows the production of CT-reconstructed VEIs. We applied simulation based on VEIs to endoscopic operations for mucocele or sinusitis. Results: In nine cases of mucoceles and sinusitis, simulation based on animated VEIs was applied. According to the simulation, surgeries were performed, and the mucoceles and obstructed sinuses could be opened readily and safely. This system was more effective when there were landmarks such as polyps or irregular mucosal surfaces allowing macroscopic confirmation ahead of the viewpoint.

Characteristics predicting laparoscopic skill in medical students: nine years’ experience in a single center

IntroductionWe introduced laparoscopic simulator training for medical students in 2007. This study was designed to identify factors that predict the laparoscopic skill of medical students, to identify intergenerational differences in abilities, and to estimate the variability of results in each training group. Our ultimate goal was to determine the optimal educational program for teaching laparoscopic surgery to medical students.MethodsBetween 2007 and 2015, a total of 270 fifth-year medical students were enrolled in this observational study. Before training, the participants were asked questions about their interest in laparoscopic surgery, experience with playing video games, confidence about driving, and manual dexterity. After the training, aspects of their competence (execution time, instrument path length, and economy of instrument movement) were assessed.ResultsMultiple regression analysis identified significant effects of manual dexterity, gender, and confidence about driving on the results of the training. The training results have significantly improved over recent years. The variability among the results in each training group was relatively small.ConclusionsWe identified the characteristics of medical students with excellent laparoscopic skills. We observed educational benefits from interactions between medical students within each training group. Our study suggests that selection and grouping are important to the success of modern programs designed to train medical students in laparoscopic surgery.

Effectiveness of Second-Generation Antihistamine for the Treatment of MorningSymptoms Observed in Patients with Perennial Allergic Rhinitis: ComparisonStudy of Bepotastine Besilate versus Olopatadine Hydrochloride

Objective: The aim of the present study was to examine circadian rhythm-based treatment strategies with the intension of improving the pharmacotherapy for morning symptoms with perennial allergic rhinitis. We investigated the effects of two second generation antihistamines, with different pharmacokinetic parameters, bepotastine besilate and olopatadine hydrochloride, for the treatment of morning symptoms. Methods: Twenty-four subjects with perennial allergic rhinitis were recruited for this study. They were randomly allocated to either a bepotastine group (n=10) or an olopatadine group (n=14). During the 1-hour period after waking up in the morning, the patients counted and recorded the number of sneezes and nose blowing. PNIF was also measured. The study participants took the allocated medicine twice a day. They continued recording their nasal symptoms and PNIF after awakening for 10 to 14 days. Results: In both group, taking bepotastine and olopatadine, the mean sneezing count and the mean nose blowing count were well suppressed. However, a significant change in the nasal congestion score was not observed throughout the study. Especially in olopatadine group, PNIF increased from day 2 onward and a significant increase was observed for the following 10 days. Conclusion: The worsening of nasal symptoms after awakening that is associated with perennial allergic rhinitis has a significant impact on the quality of life of patients. Two second-generation antihistamines, bepotastine besilate and olopatadine hydrochloride, were effective for the treatment of these morning symptoms. The measurement of Peak Nasal Inspiratory Flow (PNIF) value might lead to a favorable self-evaluation of nasal symptom and treatment effects. Some guidance regarding the taking of medicine from Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation the viewpoint of chronotherapy might improve the satisfaction of patients with the results of pharmacotherapy.