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BACKGROUND: Single strong premature electrical stimulation (S(2)) may induce figure-eight reentry. We hypothesize that Ca current-mediated slow-response action potentials (APs) play a key role in the propagation in the central common pathway (CCP) of the reentry. METHODS: We simultaneously mapped optical membrane potential (V(m)) and intracellular Ca (Ca(i)) transients in isolated Langendorff-perfused rabbit ventricles. Baseline pacing (S(1)) and a cathodal S(2) (40-80 mA) were given at different epicardial sites with a coupling interval of 135 +/- 20 ms. RESULTS: In all 6 hearts, S(2) induced graded responses around the S(2) site. These graded responses propagated locally toward the S(1) site and initiated fast APs from recovered tissues. The wavefront then circled around the refractory tissue near the site of S(2). At the side of S(2) opposite to the S(1), the graded responses prolonged AP duration while the Ca(i) continued to decline, resulting in a Ca(i) sinkhole (an area of low Ca(i)). The Ca(i) in the sinkhole then spontaneously increased, followed by a slow V(m) depolarization with a take-off potential of -40 +/- 3.9 mV, which was confirmed with microelectrode recordings in 3 hearts. These slow-response APs then propagated through CCP to complete a figure-eight reentry. CONCLUSION: We conclude that a strong premature stimulus can induce a Ca(i) sinkhole at the entrance of the CCP. Spontaneous Ca(i) elevation in the Ca(i) sinkhole precedes the V(m) depolarization, leading to Ca current-mediated slow propagation in the CCP. The slow propagation allows more time for tissues at the other side of CCP to recover and be excited to complete figure-eight reentry.  相似文献   
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Background

Rupatadine, a novel nonsedating second-generation H1-antihistamine with antiplatelet-activating factor activity, has been used in the treatment of allergic rhinitis and urticaria in European countries since 2003. However, its efficacy and safety in Japanese patients with chronic spontaneous urticaria (CSU) are unknown.

Methods

We conducted a prospective, multicenter, randomized, placebo-controlled, double-blind study in adolescent and adult CSU outpatients aged 12 to < 65 years (JAPIC-CTI No. 152786). Overall, 94, 91, and 92 eligible patients orally received placebo, rupatadine 10 mg, and 20 mg once daily for 2 weeks, respectively. The primary endpoint was change from baseline to the second week of treatment in total pruritus score (TPS, sum of daytime and nighttime pruritus scores).

Results

The results yielded a least squares mean TPS difference of ?1.956 between rupatadine 10 mg versus placebo, and ?2.121 between rupatadine 20 mg versus placebo (analysis of covariance, both P < 0.001). The incidence of adverse events was 8.5% for placebo, 20.9% for rupatadine 10 mg, and 17.4% for rupatadine 20 mg. Somnolence was the only adverse drug reaction to rupatadine reported in 2 or more subjects. No serious or clinically significant adverse events were observed.

Conclusions

The primary and secondary efficacy endpoints consistently favored rupatadine 10 and 20 mg doses over the placebo. No noteworthy dose-related increase in the incidence of adverse drug reactions was observed. Rupatadine is safe and effective at a dose of 10 mg once daily, and can be safely increased to 20 mg once daily, as necessary.  相似文献   
24.
A 36-year-old woman with rheumatoid arthritis was admitted to our hospital for evaluation of newly developed active systemic lupus erythematosus (SLE). After hospitalization, she showed progressive respiratory failure. Chest CT revealed exacerbation of interstitial pneumonia, showing acute development of air-space consolidation and ground-glass opacity in addition to intensified reticular shadows. Administration of high-dose corticosteroids and cyclosporine A resulted in recovery from respiratory failure, accompanied by obvious improvement in the chest radiographs and CT, as demonstrated by the disappearance of air-space consolidation and ground-glass opacity. Clinically, the exacerbation of her interstitial pneumonia was compatible with acute lupus pneumonitis, a rare complication with active SLE.  相似文献   
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Clinical Rheumatology - We treated two patients with severe respiratory failure due to coronavirus disease 2019 (COVID-19). Case 1 was a 73-year-old woman, and Case 2 was a 65-year-old-man. Neither...  相似文献   
28.
Solid basaloid adenoid cystic carcinoma (SB‐AdCC) is a subtype of breast AdCC which shows more aggressive clinical behavior than other subtypes. Fine‐needle aspiration (FNA) cytology is a useful diagnostic tool for breast malignancies. However, most of the diagnostic cytological characteristics of AdCC are not present in SB‐AdCC and cytomorphological studies of this subtype are limited. Here, we evaluated the utility of FNA in the diagnosis of SB‐AdCC of the breast. A search of the pathology archives of our institutions for FNA specimens of histologically confirmed SB‐AdCC between 2012 and 2019 identified four patients with SB‐AdCC of the breast. All patients were female and the average age was 60 years. Cytologically, one case was classified as malignant, two as indeterminate, and one as unsatisfactory. Smears had low to moderate cellularity. All smears showed ribbon‐like material surrounding the clusters and a vertical nuclear arrangement toward the peripheral rim. Hyaline globules appeared only in one case. Cells in all cases showed an oval, angular, and spindle shape hyperchromatic nuclei with mild to severe atypia, and also dispersed naked nuclei similar to the cells of the clusters were detected in one case. In histological sections, these cytological findings were compatible with the histological findings and divergent histological differentiation was detected. Diagnosing of few cellular smears of SB‐AdCC is difficult whereas the features of peripheral rim of the clusters, naked nuclei, and the divergent differentiation may be important for diagnosing SB‐AdCC of the breast.  相似文献   
29.
Since information concerning reflux oesophagitis in the elderly is limited, particularly in Japan, the severity and symptomatic profiles of reflux oesophagitis in elderly patients were investigated. One hundred and nineteen patients with reflux oesophagitis found among 2278 endoscopy cases between 1993 and 1996 were investigated in this study. The patients were divided into two groups, elderly and non-elderly. The severity of reflux oesophagitis was estimated by the Los Angeles classification. The presence or absence of typical symptoms (heartburn and regurgitation) was determined by interview. Reflux oesophagitis was not only more frequently found in the elderly group, but was more severe than in the non-elderly. Although the degree of manifestation of typical symptoms was similar between the elderly and the non-elderly with high-grade oesophagitis, the elderly patients with mild reflux oesophagitis were less symptomatic than the non-elderly. Mild reflux oesophagitis in the elderly may be missed due to its rarity of typical reflux symptoms and a substantial number of elderly persons might have subclinical reflux oesophagitis.  相似文献   
30.
With increasing expectations for carbon neutrality, dry reforming is anticipated for direct conversion of methane and carbon dioxide: the main components of biogas. We have found that dry reforming of methane in an electric field using a Pt/CeO2 catalyst proceeds with sufficient rapidity even at a low temperature of about 473 K. The effect of the electric field (EF) on dry reforming was investigated using kinetic analysis, in situ DRIFTs, XPS, and DFT calculation. In situ DRIFTs and XPS measurements indicated that the amount of carbonate, which is an adsorbed species of CO2, increased with the application of EF. XPS measurements also confirmed the reduction of CeO2 by the reaction of surface oxygen and CH4. The reaction between CH4 molecules and surface oxygen was promoted at the interface between Pt and CeO2.

In the dry reforming of methane in an electric field, the reaction between CH4 molecules and surface oxygen was promoted at the interface between Pt and CeO2.  相似文献   
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