X‐ray Radiation Causes Electromagnetic Interference in Implantable Cardiac Pacemakers

Background: X‐rays are not thought to cause electromagnetic interference (EMI) in implantable cardiac pacemakers. However, x‐ray radiation during computed tomography (CT) scanning has been reported to cause EMI in some implantable cardiac pacemakers. The objectives of this study were to identify the location within the pacemakers where x‐ray radiation causes EMI and to investigate the association of EMI with the x‐ray radiation conditions. Methods: We verified the location where x‐ray radiation caused EMI using a CT scanner and conventional radiographic x‐ray equipment. An inhibition test and an asynchronous test were performed using five types of implantable cardiac pacemakers. Results: X‐ray radiation inhibited the pacing pulses of four types of implantable cardiac pacemakers when the body of each implantable cardiac pacemaker, containing a complementary metal‐oxide semiconductor (CMOS), was scanned using a CT scanner. We confirmed that x‐ray‐induced EMI depends on the x‐ray radiation conditions, that is, the tube voltage, tube current, x‐ray dose, and direction of x‐ray radiation, as well as the sensing thresholds of the implantable cardiac pacemakers. Conclusions: X‐ray radiation caused EMI in some implantable cardiac pacemakers, probably because the CMOS component was irradiated. The occurrence of EMI depended on the pacemaker model, sensing threshold of the pacemaker, and x‐ray radiation conditions. (PACE 2010; 33:1174–1181)     

Promoting the effects of intravesical instillation of saline on bladder lesion development in rats pre-treated with BBN

BACKGROUND: At present, immunotherapeutic agents such as bacillus Calmette-Guerin (BCG) and anti-tumor chemotherapeutic agents in saline are used intravesically in patients with bladder carcinoma. However, of greater significance is the possibility that the saline vehicle may itself promote carcinoma development in the bladder. METHODS: The potential promoting effects of intravesical instillation of saline were assessed in female F344 rats. The animals were divided into 3 groups, all of which received 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in their drinking water for the first 10 weeks. They were then maintained without further treatment (group 1) or received intravesical instillations of 0.3 mL of saline or distilled water once a week for 6 weeks, 15 weeks after the end of the BBN treatment (groups 2 and 3). At 32 weeks, all the animals were killed and examined immunohistochemically with proliferating cell nuclear antigen (PCNA) antibody, as well as by routine histopathologic examination. RESULTS: Both the incidence and the number of bladder carcinomas were higher in the animals that received instillations of saline than in those who did not receive the instillations. Significant increases in tumor size were also noted for the saline-treated groups, although this was not linked with the PCNA labeling index. CONCLUSIONS: The results indicate that saline is a promoter of urinary bladder carcinogenesis either because of the catheterization or the fluid itself.     

Economic evaluation of Helicobacter pylori eradication for the treatment of duodenal ulcer disease in Japan: A decision analysis to assess eradication strategy in comparison with a conventional strategy

To evaluate the socio-economic effects of Helicobacter pylori eradication in the treatment of duodenal ulcer disease in Japan, a clinical decision analysis was performed to assess H. pylori eradication therapy compared with the conventional strategy of maintenance with histamine-2 receptor antagonists. A decision tree-based state transition model (Markov chain approach) implemented to simulate a 5 year period of follow up was constructed. The H. pylori eradication strategy was found to be superior to the conventional maintenance strategy with regard to clinical effectiveness and other dimensions of a patient’s outcome. Furthermore, in a long-term perspective, the eradication strategy was less costly than the maintenance strategy. Helicobacter pylori eradication should be recommended as the ?rst choice treatment of H. pylori-positive duodenal ulcer patients. The clinical implication of H. pylori eradication entails an improvement in clinical effectiveness and other dimensions of a patient’s outcome and a signi?cant reduction in the costs of duodenal ulcer treatment. The long-term total costs do not depend on the initial drug cost of an eradication regimen. Pursuing a high eradication rate of H. pylori is essential in improving the patient’s outcome and the cost-effectiveness of treatment.     

Two Cases of Bladder Carcinoma with Similar Initial Features That Exhibited Completely Different Clinical Courses

Two cases of bladder carcinoma are described. The patients wereof similar age, were both smokers and were treated for the sameperiod, but exhibited completely different later clinical courses.Initially, both had a single, papillary, pedunculate tumor,identified as a transitional cell carcinoma, grade 2. pTa. Onepatient, six years later, had multiple papillary tumors coveringalmost all the mucosal surface and underwent simple cystectomy.Histologically the tumors were identified as transitional cellcarcinomas, grade 2, pT1. The other patient, nine years later,had a single nodular invasive tumor with a concomitant, verytiny papillary tumor and underwent radical cystectomy. Histologicallythe tumor was transitional cell carcinoma, grade 2>3, pT4.Many of the questions raised by these cases are unanswered,but comparison of such cases should provide sonic cities tothe natural history of bladder carcinoma.