Differential Role of Epicardial and Endocardial KATP Channels in Potassium Accumulation During Regional Ischemia Induced by Embolization of a Coronary Artery with Latex

Epicardial and and Endocardial [K⁺]₀ Rise and K_ATP Channels. Introduction: K_ATP channels are activated predominantly in the epicardium during regional ischemia. Therefore, the role of K_ATP channels in ischemia-induced rise of extracellular potassium concentration ([K⁺]_o) might he greater in the epicardium. Methods and Results: In 18 anesthetized dogs, the left anterior descending coronary artery (LAD) was ligated, followed by injection of 23-μm latex heads into the occluded artery to interrupt collateral flow, by which accumulated [K⁺]_o might wash out. Epicardial and endocardial [K⁺]_o were measured during a 20-minute period of ischemia using a valinomycin membrane. The dogs were divided into three groups: 6 control dogs (CTRL); 7 dogs pretreated with intravenous glibenclamide (0.3 mg/kg [GLIB]), a blocker of K_ATP channels: and 5 dogs pretreated with intravenous nicorandil (0.2 to 0.25 mg/kg [NCR]), a K_ATP channel opener. Before LAD occlusion, there was no difference in [K⁺]_o among the three groups. In the control group, epicardial and endocardial [K⁺]_o were increased to a similar level as a function of time after occlusion (CTRL) at both layers. Ischemia-induced epicardial [K⁺]_o rise was suppressed by GLIB (8.4 ± 0.4 vs 6.7 ± 0.5 mM, P < 0.05) but augmented by NCR (12.9 ± 2.0 mM, P < 0.05). In contrast, endocardial [K⁺]_o, rise remained unaffected (7.6 ± 0.2 mM CTRL, 7.6 ± 1.3 mM GLIB, and 9.4 ± 2.2 mM NCR, P = NS). Conclusion: Activation of K_ATP channels plays an important role in epicardial [K⁺]_o rise, but not in endocardial [K⁺]_o rise, during regional ischemia. Another mechanism(s) may he important for endocardial [K⁺]_o accumulation.     

江苏宜兴地区中小学生常年性变应原致敏状况调查

目的:观察江苏宜兴地区中小学生的常年性变应原致敏状况。方法:2002￣2003年以宜兴市丁山镇930名中小学生(6～16岁)为对象进行室尘和尘螨变应原皮肤划痕试验。结果:室尘和尘螨变应原的皮试阳性率分别为13.1%和10.0%,总阳性率为17.5%。CochranArmitage趋势分析表明,变应原致敏率随年龄增长而上升(P<0.005);小学一、四年级与初中一年级各组间变应原致敏率无统计学差异,而高中一年级学生的致敏率明显高于其他各年级组(P<0.005)。结论:宜兴地区中小学生对常年性变应原的致敏随年龄呈增加趋势,尤以高中学生的致敏率上升为著,应加强环境干预。     

Impaired expression of MHC class II molecules in response to interferon-gamma (IFN-γ) on human thymoma neoplastic epithelial cells

A human thymoma is a neoplasm derived from the thymic epithelial cell, and is well known for its association with autoimmune diseases, especially myasthenia gravis. The neoplastic epithelial cells of thymoma clearly retain thymic epithelial functions, but the development of T cells in thymoma is somewhat impaired. In this study, we quantified by flow cytometry the in vitro expression of MHC molecules on neoplastic epithelial cells precultured with IFN-γ. While MHC class I expression was comparable with that on normal thymic epithelial cells, the level of MHC class II molecules on neoplastic epithelial cells was lower than in controls, and also varied greatly from case to case. Additionally, there was a significant positive correlation between the expression level of MHC class II and the proportion of mature CD3⁺ cells in the CD4⁺CD8^? subset. Thus, accumulation of CD3^?CD4⁺CD8^? cells in thymoma may result from impaired expression of the MHC class II molecules, suggesting that the function of the neoplastic epithelial cells might determine the maturation and the positively selected repertoire of T cells in thymomas.     

Application of Peroral Cholecystoscopy in a Case of Cholecystocolic Fistula

A patient with a cholecystocolic fistula, complicating cholecysto-choledocholithiasis, was treated endoscopically with gallbladder observation by peroral cholecystoscopy (POCCS). The patient was a 71-year-old female admitted to our hospital for investigation and treatment of biliary stones and a cholecystocolic fistula. Endoscopic lithotripsy and extracorporeal shock wave lithotripsy (ESWL) were performed after endoscopic sphincterotomy, and the gallbladder was subsequently investigated using a duodenoscope/ cholangioscope of the mother and baby type. Full distension of the gallbladder with saline solution allowed POCCS observation of the entire surface. The gallbladder mucosa was smooth, and neither stones nor tumors were observed. Though the cholecystocolic fistula itself could not be observed, we concluded that it had resulted from cholecystitis. Peroral cholecystoscopy is thus a useful method of investigating the gallbladder in such cases.     

Neural substrates of emotionally valenced episodic memory: A PET study using film stimuli

Abstract  To reveal the pathogenetic mechanism of post-traumatic stress disorder (PTSD), we modeled the 're-experience' symptom of PTSD in healthy subjects, and investigated its neural substrates using PET activation experiments on an emotionally (fear) valenced episodic memory task and several contrast tasks. Ten right-handed healthy male volunteers underwent H₂¹⁵O-PET. Each subject was required to watch a horror film the previous day. During the PET scan, the subject was shown part of the film for 60 s immediately before the terrifying climax scene and told to recall the following scene. The subject did not watch the scene directly, but re-experienced fear induced by the trigger. The rCBF in this task compared with that in control tasks was analyzed with SPM99. The subjective emotional state of the subject in each task was evaluated using an analog scale. The main cerebral areas where rCBF significantly correlated with the task of emotionally valenced episodic memory, compared with the novel emotional task, were the left retrosplenial cortex (Brodmann's area: BA 31), the left visual association cortex (BA 19) and the right prefrontal cortex (BA 10). Although the retrosplenial cortex or the posterior cingulate gyrus has been regarded as engaged in processing either only emotion or only episodic memory, this area is considered to be involved in processing 'emotionally valenced episodic memory'.     

Risk Factors For Duodenal Ulcer Recurrence: Three-year Follow-up during Famotidine Maintenance Therapy

The recurrence-free rate and factors related to recurrence after healing were investigated in duodenal ulcer patients on H₂-blocker maintenance therapy with famotidine. Famotidine maintenance therapy (20 or 40 mg once a day before bedtime) was performed in 488 evaluable patients after endoscopically-proven healing of ulcers (S₁ or S₂). The cumulative recurrence-free rates were 81.1%, 65.1% and 58.2%, respectively, after one, two and three years of maintenance therapy. Among various background factors, those which have been suggested to be closely associated with ulcer recurrence were compared on the basis of their relation to the recurrence-free rate. These factors included a past history of duodenal ulcer, smoking, alcohol use, bulbar deformation, the endoscopic stage of ulcer healing, concomitant drugs and compliance with famotidine therapy. Recurrence correlated most significantly with a past history of duodenal ulcer and with compliance. Compliance was categorized as excellent, good, fair or poor. The recurrence-free rate was significantly lower in patients with excellent compliance than in any other compliance group. A famotidine dose of 40 mg/day (the standard dose), versus the half dose of 20 mg/day, produced no significant difference in the cumulative recurrence-free rate and it was therefore suggested that 20 mg/day of famotidine is comparable to 40 mg/day in its preventive effect on duodenal ulcer recurrence. In addition, because recurrence was more common in patients who had previously experienced recurrence, a past history of ulcer was suggested to be a significant risk factor for ulcer recurrence.     

Quantitative measurements of Hemophilus influenzae type b capsular polysaccharide antibodies in Japanese children

BACKGROUND: Hemophilus influenzae type b (Hib) infection has a high morbidity and mortality rate in children. The frequency of natural immunity against Hib in Japanese children is not known, and Hib vaccine has not yet been introduced in Japan. METHODS: Anti-capsular polysaccharide-specific IgG (anti-CP) antibody titers were examined in serum samples from 100 children and 107 young adults who were not vaccinated against Hib, in serum samples from eight patients with Hib systemic infection and in 10 commercially available human immune globulin preparations on enzyme-linked immunosorbent assay. RESULTS: A total of 44% (44/100) of Japanese children and all patients with Hib systemic infection in the acute phase did not have the minimum protective level of anti-CP antibodies (>0.15 microg/mL). The rate of natural Hib immunity was lowest in children under 1 year of age and gradually increased with age. Only 3.74% (4/107) of Japanese young adults did not have the minimum protective level of anti-CP antibodies. Analysis of 10 commercially available human immune globulin preparations indicated an average level of 28.25 microg anti-CP antibody/mL immune globulin (range 14.96-44.17 microg/mL). CONCLUSIONS: Approximately half of Japanese children are not protected against Hib infection. Therefore, Hib vaccine should immediately be included as part of the routine immunization program in Japan. It was also found that all tested commercially available immune globulin preparations had high anti-CP titers. Well-controlled clinical trials of i.v. immune globulin administration for prevention and treatment of Hib systemic infection are needed in Japan.