Shear bond strengths of indirect resin composites to hybrid ceramic

A hybrid ceramic, Estenia, is a highly-filled composite for indrect use. The purpose of this study was to measure the shear bond strength between Estenia and six incremental materials: Estenia, Cesead II, Epricord, Gradia, Prossimo, and Solidex. Five specimens were prepared for each group, and all specimens were subjected to shear bond strength testing at a cross-head speed of 1 mm/min. Data were analyzed using two-way ANOVA and Dunnett's T3 test at 95% confidence level. The results indicated that the shear bond strength of Estenia to Estenia was significantly lower than that of any other combinations. Apart from storage condition that was found to influence shear bond strength statistically, thermal cycling of the specimens also tended to decrease the bond strength between Estenia and the incremental materials. It was concluded that regularly-filled composites are suitable to be used as an incremental material facing Estenia in combination technique.     

Influence of cavity configuration on the adhesion of two resin-based composites to pulpal floor dentin

PURPOSE: To evaluate the effect of cavity configuration on microtensile bond strengths of two resin composites for core build-up to pulpal floor dentin. METHODS: Access cavity preparation and root canal filling with gutta percha were performed on extracted human molars. Following this, the gutta percha in the pulp chamber was completely removed to expose pulpal floor dentin. The cavity walls remained as a control group (Cavity). For another group, the cavity walls were removed to create a flat surface for bonding (Flat). For the Cavity group, Clearfil SE Bond was applied to the cavity according to the manufacturer's instructions, and either a light-cured resin composite (PH, Clearfil Photo Core) or a dual-cured resin composite (DC, Clearfil DC Core), was placed in the bonded cavity. Clearfil Photo Core was placed in three increments while bulk-filling was used for Clearfil DC Core. The application of the bonding system and the composites to the flat dentin surface was the same as that for cavity. Specimens were stored in water for 1 week, then sectioned vertically into 2 or 3 slabs (0.7 mm thick) and trimmed for the microtensile bond strength (MTBS) test. The MTBSs were measured with a universal testing machine at a crosshead speed of 1.0 mm/minute. RESULTS: The results (mean +/- SD, MPa, n=10) of PH/Cavity, PH/Flat and DC/Flat were 21.9 +/- 3.4, 28.9 +/- 4.0, and 27.6 +/- 6.1 respectively. The MTBS could not be determined in DC/Cavity because of debonding occurred during sample preparation.     

Open-ended questions: are they really beneficial for gathering medical information from patients?

Open-ended questions, which allow patients to discuss their concerns freely, are widely considered an efficient method gathering medical information from patients during a medical interview. However, few studies have examined the relationship between the use of open-ended questions and the amount of information obtained from patients during the medical interview. This study examines this relationship using a relatively large sample size under more standardized conditions than in previous studies. The Japanese Group for Research on the Medical Interview undertook this research in 2002-2003. A total of 1,527 medical students conducted medical interviews with standardized patients, and 1,220 met the inclusion criteria for this study. The interview was limited to five minutes. Evaluators (medical school faculty physicians) evaluated the use of open-ended questions during the medical interview. The reliability of the evaluation sheet was also examined. The amount of information obtained was measured through the medical interview evaluation sheet. The use of open-ended questions was positively related to the amount of information elicited from the patients (F = 41.0, p < 0.0001). This study provides data to support the hypothesis regarding the favorable relationship between the use of the open-ended questions and the amount of information from the patients.     

Perisaccadic perception of continuous flickers

To realize perceptual space constancy, the visual system compensates for the retinal displacement caused by eye movements. It has been reported that the compensation process does not function perfectly around the time of a saccade--a perisaccadic flash is systematically mislocalized. However, observations made with transient flash stimuli do not necessarily indicate a general perisaccadic failure of space constancy. To investigate how the visual system realizes perisaccadic space constancy for continuous stimuli, we examined the time course of localization for a perisaccadic 500 Hz flicker with systematic variation of the onset timing, the offset timing and the duration. If each flash in the flicker is localized individually in the same way as a single flash, the apparent position and length of the flicker should be predicted from the time course of mislocalization of a perisaccadic flash. However, the results did not support this prediction in many respects. A dot array (of half the length of the retinal image) was perceived when the flicker was presented during a saccade, while only a single dot was perceived when the flicker was presented only before or after the saccade. A flash in a flicker was localized at a different position, depending on the onset timing, the offset timing and the duration of the flicker, even if the flash was presented at the same timing to the saccade. In general, our results support a two-stage localization in which the local geometrical configuration is first generated primarily based on the retinal information, and then localized as a whole in the egocentric or exocentric space. The localization is based on the eye position signal sampled at a time temporally distant from the saccade, which enables precise localization and space constancy for continuous stimuli.     

Effective use of combination chemotherapy with paclitaxel and 5-fluorouracil in a case of non-resectable advanced gastric cancer

The patient was a 67-year-old man who had gastric cancer located in the posterior wall of the stomach and who underwent surgery on June 27, 2001. The operative finding was carcinomatous peritonitis in which the primary lesion was considered to be surgically unresectable. Therefore, only a probe laparotomy was performed. Under full informed consent, we performed combination chemotherapy with paclitaxel and 5-fluorouracil, 5-fluorouracil (600 mg/m2/day) was infused continuously for 120-hours (day 1-5) on administration and paclitaxel (60 mg/m2) was infused for 1.5 hours after premedication at day 8, 15 and 22 on an outpatient basis. After 2 courses of the chemotherapy, the tumor markers were reduced remarkably, ascites had completely disappeared, and abdominal lymph nodes had decreased. No serious adverse event was observed and the patient maintained good QOL throughout the treatment.     

Alum augments the experimental allergenicity of Kunitz-type soybean trypsin inhibitor independent of the antigen-adsorption

In order to inspect the significance of the adsorbing property in the adjuvant activity to enhance IgE production, we immunized BALB/c mice against Kunitz-type soybean trypsin inhibitor (KSTI), the most potent experimental allergen among soybean proteins, associated with Aluminum hydroxide (alum) or DEAE-Sephadex particles. The production of immunoglobulin isotypes was analyzed at the various amounts, 3-3,000 microg per mouse, of the antigen dosages. In our experiments, although alum did not adsorb KSTI significantly, it augmented the total and the antigen-specific IgE without affecting the optimal range of the antigen dosage. On the other hand, alum did not effectively enhance the production of the other immunoglobulin isotypes. The production of immunoglobulin isotypes other than IgE increased dose-dependently on the antigen. These results ensured our previous finding that another protein, ovalbumin, was used as the antigen. We also demonstrated that the adsorption of KSTI by DEAE-Sephadex in the immunizing vehicle resulted in the requirement of more KSTI for accomplishing the equal immunity in BALB/c mice compared to the control. Moreover, we demonstrated that, regardless of the inability to adsorb KSTI, alum exerted its adjuvant activity only when it was co-injected with the antigen. These results showed that some biochemical effect, other than adsorptive activity, to enhance the production of the antigen-specific IgE resides in alum.