Decreased anti-parietal cell antibody titer in the advanced phase of autoimmune gastritis.

BACKGROUND: Autoimmune gastritis (AIG) is histologically classified into three phases according to the severity of oxyntic mucosal atrophy: early, florid, and end phases. This study aimed to clarify the relationship between the AIG phase and the anti-parietal cell antibody titer. METHODS: Patients who underwent upper gastrointestinal endoscopy were retrospectively reviewed in this study. We enrolled patients who were histologically diagnosed with AIG and serologically tested for anti-parietal cell antibody (APCA). AIG patients were classified into three groups: early, florid, and end phase groups. Clinical characteristics, including APCA titers, were compared among these three groups. RESULTS: A total of 44 AIG patients were enrolled. There were two patients in the early phase, 11 in the florid phase, and 31 in the end phase. APCA-positive rates were 100% in the early phase, 90.9% in the florid phase, and 90.3% in the end phase. The mean APCA titer was 480 U in the early phase, 220 U in the florid phase, and 150 U in the end phase. There was a stepwise decrease in the APCA titer from the early phase to the end phase. The mean APCA titer for the end phase was significantly lower than that of the early phase or florid phase. Additionally, there was a stepwise decrease in serum gastrin levels from the early phase to the end phase. CONCLUSION: AIG progresses from the early phase to the end phase, and the APCA titer shows a decrease. The negativity of APCA could occur, especially in the end phase.

Highly durable double sol-gel layer ratiometric fluorescent pH optode based on the combination of two types of quantum dots and absorbing pH indicators.

Long-term stable ratiometric fluorescent optical pH sensors (optodes) based on double sol-gel silica layers are prepared with the first layer embedding two types of quantum dots (QDs) and the second layer embedding light-absorbing pH indicators. The sensors are fabricated by a simple general sol-gel spin-coating method. The resulting double-layer pH optodes are designed as having long Stokes shift as well as ratiometric fluorescence emission response to pH in aqueous solutions of varying pH values. This optode has high durability against continuous light exposure, even under severe acidic condition (1 M HCl), and the storage stability is over a period of more than 6 months. These results indicate that the double-layer ratiometric fluorescence-based pH optode allows for long-term pH sensing. When two pH indicators of different pK(a) values with an optimized mixing ratio are embedded into the second layer, a double-layer pH optode with reproducible linear response in a wide pH range of over 6 pH units (from pH 4 to 10) can be designed and fabricated.

Verapamil suppresses the inhomogeneity of electrical remodeling in a canine long-term rapid atrial stimulation model.

Verapamil is known to suppress shortening of the atrial effective refractory period (AERP) during relatively short-term atrial pacing, although the effect of a long-term stimulation model is unclear. The effect of verapamil on electrical remodeling was evaluated in a canine rapid atrial stimulation model. The right atrial appendage (RAA) was continuously paced (400 beats/min) for 2 weeks. Four pairs of electrodes were sutured at four atrial sites; the RAA, right atrium close to the inferior vena cava, Bachmann's bundle, and LA. AERP, AERP dispersion (AERPd), conduction time, and inducibility of AF were evaluated during the pacing phase and the recovery phase. The same protocol was performed under the administration of verapamil. In five control dogs, the AERP shortening was inhomogeneous and the shortening of the AERP was most prominent in the LA. AERPd increased during the rapid pacing phase by 5 +/- 2 ms, but recovered quickly in the recovery phase. The max AERPd was 46 +/- 4 ms in the control group and was larger than that in the verapamil group (31 +/- 3 ms, P = 0.001). At the LA site, the shortening of the AERP was decreased by verapamil administration (-19 +/- 3 vs -5 +/- 2 ms, P = 0.04). However, the AF inducibility was not significantly different between the two groups. The effect of verapamil on electrical remodeling was inhomogeneous, depending on the anatomic portion. As a result, AERPd widening during the rapid pacing phase was suppressed by verapamil, while the AF inducibility was unchanged.