Assessing age-related change in Japanese mental foramen opening direction using multidetector computed tomography.

OBJECTIVE: The purpose of this study was to investigate how the opening direction of the mental foramen (MF) changes with age in a Japanese population using multi-detector computed tomography (MDCT). METHODS: Post-mortem MDCT scans of 121 Japanese subjects (66 males and 55 females) were carried out where all subjects possessed at least twenty teeth, including molar teeth, in the upper and lower jaws. Two angles of the mental foramen opening were measured, namely the superior-inferior angle in the coronal plane and anterior-posterior angle in the transverse plane, on the CT reconstructed images. The associations between age and these two angles were evaluated using a multiple regression analysis. RESULTS: For male subjects, the relationship between the superior-inferior angle and age was a quadratic curve (p < 0.001). This angle increased until the subject reached their early 50s and then the angle decreased with age. In the transverse plane, there was a linear relation between the anterior-posterior angle and age (p=0.002).It was noted also that the angle decreased with age. By contrast, however, no significant associations between the two angles and age for either measurement were noted for female subjects. This study demonstrated that the opening direction of the mental foramen changes with age in Japanese male subjects. By contrast this change in the opening direction of the mental foramen was not demonstrated in Japanese female subjects. In male subjects, the opening direction moves superiorly until the individual reaches their early 50s, and then moves inferiorly with advancing age. It also shifts from a posterior to an anterior position with age. CONCLUSION: These observed change differ from the results of previous studies. The findings could be useful for forensic science as they demonstrate a change in the position of mental foramen in a sample of contemporaneous male Japanese subjects.

[Comparison of the therapeutic effects and acid suppression of H2-receptor antagonist and proton pump inhibitor in patients with gastric body ulcer--a prospective controlled trial].

We studied, the rate and the affecting factor of ulcer healing of patients with gastric body ulcer treated by H2-receptor antagonist (H2-RA) and proton pump inhibitor (PPI). Gastric acidity was also examined using 24 hr pH monitoring. No difference was observed between the affecting factor of ulcer healing and healing rate (94.7% and 94.9%) among the patients treated by H2-RA or PPI. The average time below pH3 during treatment with H2-RA or PPI were 17.4 +/- 4.3 hr and 23.0 +/- 1.5 hr, respectively. Acid suppression was superior in PPI treated group than in H2-RA group. From these findings, we concluded that H2-RA had sufficient therapeutic efficacy in treating gastric body ulcer.

Control of gastric pH with ranitidine in patients with Crohn's disease receiving total parenteral nutrition. Comparison of two intravenous regimens.

Eleven patients with Crohn's disease in remission who were receiving total parenteral nutrition (TPN) underwent continuous intragastric 24-h pH monitoring before and during ranitidine administration. The patients were randomly allocated to receive 200 mg/day (group 1) or 400 mg/day (group 2) of ranitidine by continuous infusion. The mean basal 24-h gastric pH was sustained at a low value. After raintidine administration, the mean pH increased significantly both in group 1 (from 2.13 to 3.28) and in group 2 (from 1.91 to 3.36), with the mean holding-time at pH-3 also increasing significantly in both groups. There were no differences in the mean pH or holding-time at pH-3 between the two groups during ranitidine administration; however, the plasma ranitidine concentration was significantly higher in group 2. These findings indicate that the continuous infusion of a standard dose of ranitidine exerted a maximal inhibitory effect on the sustained hyperacidity induced by TPN, but that this infusion was unable to maintain the intragastric pH level at above 3.5.

[Predictable factors in healing of gastric ulcer, comparative analysis of local morphologic factor of gastric ulcer and suppression of intragastric pH].

Predictable factors in healing of 48 patients with gastric ulcer by PPI or H2-RA on 4 and 8 weeks of treatment were investigated. We evaluated the following factors such as patient's profile, local morphologic factors of gastric ulcer and suppression rate of 24 hr intragastric pH between healed and unhealed patients using single and multiple variable analysis. Results obtained from multiple variable analysis, the significant and independent factors of intractable gastric ulcers on the 4th week of treatment were ulcer size in over 20 mm and solitary ulcer. On the contrary, those of 8th week of treatment were shortage of holding time of intragastric pH over pH4 (less than 16.7 hrs) during treatment, the site of ulcer at lesser curvature of gastric angle and the shape of ulceration which showed mucosal overhanging. Considering with single and multiple variable analysis, we concluded that, in early phase, local shapes of the ulceration were important predictors in the healing of gastric ulcer, and the after that, the inhibition of intragastric acidity were significant factors in healing process of gastric ulcer.

Comparison of the effects of single morning and single bedtime doses of famotidine on intragastric acidity in patients with gastric ulcer.

The effects of single morning and single bedtime doses of famotidine on intragastric acidity were studied by 24-h intragastric pH monitoring in 16 patients with gastric ulcer. The patients were randomly allocated to the following regimen: one group (n = 8) received 40 mg famotidine at 8:30 AM and another group (n = 8) received the same dose at 10 PM. The morning group showed significant inhibition of gastric acidity during the 24-h and daytime measurements, compared to those of the bedtime group (p < 0.05 in 24 h, p < 0.01 in daytime). Conversely, the bedtime group showed a significant inhibition of gastric acidity during the nocturnal period compared to the morning group (p < 0.01). These results indicate that the relative importance of suppression of gastric acidity on the gastric ulcer healing process should be evaluated in a clinical trial.

Extracellular ATP-induced regulation of epidermal growth factor signaling in cultured renal LLC-PK1 cells.

We investigated the effect of extracellular ATP on the interaction of epidermal growth factor (EGF) with its receptor in cultured renal epithelial cells, LLC-PK1. Pretreatment with ATP, but not adenosine, inhibited the binding of 125I-labeled EGF. The inhibition demonstrated by ATP resulted from a decrease in the affinity of EGF receptors for its ligand, with no change in the number of EGF receptors. Incubation of phorbol 12-myristate 13-acetate (PMA) for 30 min mimicked the ATP-mediated inhibition. On the other hand, prolonged pretreatment with PMA, which leads to disappearance of protein kinase C activity, reversed the inhibition. In addition, pretreatment with the protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine prevented the ATP-mediated inhibition. ATP triggered an increase in inositol 1,4,5-trisphosphate levels and translocation of protein kinase C from cytosol to membranes, consist with the stimulation of phospholipase C and the activation of protein kinase C. These results demonstrate that extracellular ATP attenuates the ligand binding affinity of EGF receptor via the stimulation of phospholipase C, leading to the activation of protein kinase C in the LLC-PK1 cells.