The binding of [3H]‐(R)α‐methylhistamine and [3H]‐Nα‐methylhistamine to histamine H3‐receptors, [3H]‐SCH23390 to dopamine D1‐receptors, and [3H]‐YM09151‐2 to dopamine D2‐receptors was investigated by quantitative receptor autoradiography in the rat brain following 6‐hydroxydopamine injection into the substantia nigra. The levels of [3H]‐(R)α‐methylhistamine binding sites in the denervated striatum and substantia nigra were significantly higher than those in the contralateral side from 1 week to 12 weeks after nigral lesions. The H3‐receptor binding was maximal at 3 weeks after nigral lesions and maintained until 12 weeks. The increased number of histamine H3‐receptors was decreased to the level of the contralateral side by chronic treatment with a selective dopamine D1 agonist, SKF38393, but not modified by a selective dopamine D2 agonist, quinpirole. Dopamine D1‐ and D2‐receptors in the striatum were similarly up‐regulated after unilateral nigral lesion. On the other hand, the number of dopamine D2‐receptors in the substantia nigra was markedly decreased after administration of 6‐hydroxydopamine. The treatment with (S)α‐fluoromethylhistidine increased the H3‐receptor binding in both the ipsilateral and contralateral sides. As a result, the magnitude of the ratio of the H3‐receptor binding between ipsilateral and contralateral sides was partially attenuated by treatment with (S)‐α‐fluoromethylhistidine. These results strongly suggest that the expression of histamine H3‐receptors in the striatum and substantia nigra is influenced through D1‐receptors by tonic nigrostriatal dopaminergic inputs.

Background Atrial fibrillation (AF) is the most common cardiac arrhythmia, with its incidence making up nearly one‐third of all hospital admissions. Atrioventricular block (AVB) is a conduction abnormality along the atrioventricular node or the His‐Purkinje system. The relationship between atrioventricular conduction block and AF is controversial. Hypothesis This study is designed to observe whether there is a correlation between AVB and AF, and which type of AVB has the most obvious correlation with AF. Methods This study retrospectively reviewed 1345 patients. We classified the AVB according to the AVB classification criteria. One hundred and two patients were excluded, and the final total sample size was 1243 patients, including 679 patients in the AF group (378, 55.7% males) and 564 patients in the non‐AF group (287, 50.8% males). AF group and non‐AF group were compared to observe the relationship between AVB and AF. Results The I AVB have a relative statistical risk of 1.927 (95% confidence interval [CI]: 1.160‐3.203, P < 0.05) with the occurrence of AF. II AVB occupied the largest proportion, accounting for 67 cases (9.87%), and the statistical risk of II AVB in AF is 16.845 (95% CI: 6.099‐46.524, P < 0.000). III AVB has a comparative statistical risk of 17.599 (95% CI: 4.212‐73.541, P < 0.000). Conclusions The three types of AVB in the AF group were significantly higher than that in the non‐AF group. II AVB has the highest incidence rate compared with other types of AVB in the AF group. AVB can be used as a risk factor for AF occurrence.

Cardiac complications of KD with CAAs include thrombosis, coronary stenosis, myocardial infarction, sudden death, and calcification. Although rare, rupture of giant CAAs is fatal and might occur earlier after the onset of disease. Mortality occurred primarily in the earlier cases when anticoagulant therapy was insufficient and in patients who did not receive regular treatment. Echocardiography can provide reliable information for assessing the progression and prognosis of this condition.

Background: NT Pro-BNP is a blood marker secreted by cardiomyocytes. Myocardial stretch is the main factor to stimulate NT Pro-BNP secretion in cardiomyocytes.NT Pro-BNP is an important risk factor for cardiac dysfunction, stroke, and pulmonary embolism. So does atrial myocyte stretching occur when patients have atrial fibrillation (AF)? Whether atrial muscle stretch induced by AF leads to increased NT Pro-BNP remains unclear. The purpose of this study is to investigate the relationship between NT Pro-BNP and AF.Hypothesis: AF can cause changes in myocardial tension. Changes in myocardial tension may lead to increased secretion of NT Pro-BNP. We hypothesize that NT Pro-BNP may increase in AF with or without LAD enlargement.Methods: This clinical study is an observational study and has been approved by the Ethics Committee of the First Affiliated Hospital of Xi'an Jiaotong University. Ethical approval documents is attached. The study retrospectively reviewed 1345 patients with and without AF. After excluding 102 patients who were not eligible, the final total sample size was 1243 cases: AF group 679 patients (378, 55.7% males) and non-AF group 564 patients (287, 50.8% males). NT Pro-BNP was observed in AF group and non-AF group with or without LAD. After adjusting for age, gender, BMI, left atrial diameter, hypertension, diabetes, coronary heart disease, and cerebral infarction, NT Pro-BNP remains statistically significant with AF. Conclusion:NT Pro-BNP can be used as a risk predictor of AF with or without left atrial enlargement.

No abstract