BACKGROUNDAdvances in catheter ablation procedures for the treatment of supraventricular arrhythmias have created the need to understand better the morphological and electrophysiological characteristics of the inferior nodal extension (INE) and transitional cellular band (TCB) in the atrioventricular (AV) junctional area.

METHODSFirstly, we observed the histological features of 10 rabbit AV junctional areas by serial sections under light microscopy. Then we recorded the action potentials (APs) of transitional cells (TCs) in the INE, TCBs, AV node, and ordinary right atrial myocytes from the AV junctional area of 30 rabbits using standard intracellular microeletrode techniques.

RESULTSUnder light microscopy, the INE appeared to be mostly composed of transitional cells linking upward to the AV node. Four smaller TCBs originated in the orifice of the coronary sinus, the region between the septal leaflet of the tricuspid valve and the coronary sinus, the inferior wall of the left atrium, and the superior interatrial septum, respectively, all linking to the INE or the AV node. Compared with ordinary atrial myocytes, the AP of the TCs in both the INE and the TCBs had a spontaneous phase 4 depolarization (not present in ordinary atrial myocytes), with a less negative maximum diastolic potential, a smaller amplitude, a slower maximum velocity of AP upstroke, and a longer action potential duration at 50% repolarization (APD50) and at 30% repolarization (APD30). The AP characteristics of these TCs were similar to those of the AV node, except that the velocities of the phase 4 spontaneous depolarization were slower and their action potential durations at 90% repolarization (APD90) were shorter. Moreover, APD50 and APD30 of the TCs of the TCBs were shorter than in the case of TCs of the AV node.

CONCLUSIONSThe TCs of the INE and TCBs are similar to slow response automatic cells. They provide a substrate for slow pathway conduction. In addition, repolarization heterogeneity exists in the AV junctional area.

Action Potentials ; Animals ; Atrioventricular Node ; cytology ; physiology ; Female ; Male ; Rabbits

We established the rapid response system for non-hospitalized patients from 2012 in order to improve the effectiveness of emergent critical care for non-hospitalized patients when emergency happened.From January 2013 to December 2016,there were 122 cases with RRS activation for non-hospitalized patients.The time to arrive was 3.16±0.41 min,and 107 cases(86.89％)were sent to the emergency department.Fifteen patients(14.02％)were classified as level 1,26(24.03％)as level Ⅱ,48(16.82％)as level Ⅲ,and 18(16.82％) as level ⅣV,and 83％ were critical patients.Rapid response system is important to cope with emergency in non-hospitalized patients.

Objective: To establish the quality control methods for the standard decoction of Puerariae Thomsonii Radix.Method:According to the preparation principles for traditional Chinese medicine (TCM) standard decoction,13 batches of Puerariae Thomsonii Radix from different origins were analyzed under the chromatography conditions established in this study and verified with methodology.By referring to Chinese Pharmacopoeia of 2015,puerarin was used as a quantitative indicator to calculate the transfer rate.In this study,the structures of main chromatographic peaks were also identified to clarify the main chemical constituents in the standard decoction.Result:The 13 batches of medicinal herbs were identified as Puerariae Thomsonii Radix,with a recovery rate of 98.0%,and RSD of 1.1%,indicating that the method was accurate and reliable.The transfer rate ranged from 41.4% to 60.0%,and the extraction rate was within the range of 15.7%-34.3%.The corresponding fingerprints were prepared for 13 batches of the standard decoction,and their similarities were all greater than 90.0%.The chemical constituents from Puerariae Thomsonii Radix were identified by mass spectrometry analysis,including citric acid,4'-O-glucosyl puerarin/daidzein-4',7-diglucoside,3'-hydroxy puerarin/genistein puerarin,puerarin apioside,daidzin puerossid A and daidzein,etc.Conclusion: The 13 batches of Puerariae Thomsonii Radix decoction in different origins had consistent properties with the basic properties of medicinal decoction pieces.The established method of quality evaluation can be used to systematically evaluate the standard decoction,providing reference for quality control of related decoction preparations of Puerariae Thomsonii Radix.

Objective: To evaluate the effect of inactivated SARS-CoV-2 vaccine on the clinical outcomes of patients infected with the Omicron variant. Methods: A total of 1 403 Omicron-infected patients admitted to 20 designated hospitals in Guangdong Province from January 1 to May 31, 2022, were selected as subjects in this study. A case-control study was conducted to collect the demographic data, underlying disease, vaccination status, last exposure date, gene sequencing of infected strains and clinical outcomes from the China Disease Prevention and Control Information System and Guangdong telemedicine platform. Pneumonia (common, severe and critical) and non-pneumonia (asymptomatic and mild) were selected as the case group and control group. The effect of inactivated SARS-CoV-2 vaccine on the clinical outcomes of patients infected with the Omicron variant was analyzed. Results: The median age [M (Q₁, Q₃)] of the subjects was 36 (27-47) years old, with males accounting for 52.25% (733 cases). The main outcome of the infection was non-pneumonia, accounting for 92.09% (1 292 cases), and the duration [M (Q₁, Q₃)] of the disease was 18 (14-22) days. There were 134 (9.55%), 39 (2.78%), 403 (28.72%), 437 (31.15%) and 390 (27.80%) cases with no or partial vaccination, within 90 days of primary vaccination, over 90 days of primary vaccination, within 90 days of booster vaccination and over 90 days of booster vaccination, respectively. Multivariate logistic regression analysis showed that after adjusting for gender, age, underlying disease, and location of the report, compared with those with no or partial vaccination, the risk of developing pneumonia was lower in those with over 90 days of primary vaccination, within 90 days of booster vaccination and over 90 days of booster vaccination [OR (95%CI) values were 0.52 (0.28-0.98), 0.39 (0.21-0.73) and 0.40 (0.21-0.77), respectively]. Cox proportional hazard regression model analysis showed that after adjusting for gender, age, underlying disease and location of the report, the duration of the disease was shorter in those who received booster vaccinated for more than 90 days compared with that in those who had no or partial vaccination [HR (95%CI): 1.26 (1.03-1.55)]. Conclusion: The inactivated SARS-CoV-2 vaccine affects the clinical outcomes of patients infected with the Omicron variant.
Adult ; Humans ; Male ; Middle Aged ; Case-Control Studies ; China/epidemiology* ; COVID-19/prevention & control* ; COVID-19 Vaccines ; SARS-CoV-2 ; Female