Comparison of Diagnostic Performance Between PI-RADS v2.1 and PI-RADS v2 for Prostate Cancer: A Meta-analysis / 肿瘤防治研究

Objective To compare the diagnostic performance of PI-RADS v2.1 and PI-RADS v2 in the detection of clinically significant prostate cancer(csPCa) by Meta-analysis. Methods The major biomedical databases were searched (CNKI, CBM, Medline, and Embase) with the keywords "PIRADS v2.1" or "PI-RADS v2.1". The Quality Assessment of Diagnostic Accuracy Studies Tool v2 (QUADAS-2) was used to evaluate literature quality. Meta-analysis was performed using STATA17.0 and ReMan5.4 software. Forest plots were used to represent the sensitivity and specificity of PI-RADS v2.1 and PI-RADS v2 for each study. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were combined, and diagnostic performance was evaluated using asummary receiver operating characteristic curve (SROC). Subgroup analysis was performed on three covariables: tumor location, threshold, and the nationality of authors. Results A total of 12 studies were included, involving 3 158 patients and 3 243 lesions. Forall zones and the whole gland, PI-RADS v2.1 had a larger area under the SROC curve (AUC) for csPCa performance, compared with PI-RADS v2. Subgroup analysis: PI-RADS v2.1 also had a larger area under the SROC (AUC) to detect transitional zone csPCa. Different diagnostic thresholds: when a score of 4 was used for the threshold, PI-RADS v2.1 had the maximum area under SROC (AUC) for csPCa performance detection. Author nationality: Researches of PI-RADS v2.1 in Chinese authors had the largest area under the SROC (AUC) in detecting csPCa performance. Conclusion Compared with PI-RADS v2, the diagnostic performance of PI-RADS v2.1 in detecting csPCa is not obviously improved and overall specificity is still low.

Effect of Qingjin Huatantang on AECOPD Inflammatory Factors by Regulating p62 / 中国实验方剂学杂志

Objective:To regulate autophagy protein p62 of airway epithelial cells in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) rats with Qingjin Huatantang, in order to explore its effect on interleukin (IL) -1β and tumor necrosis, tumor necrosis factor-α (TNF-α), leukotriene B4 (LTB4), and leukotriene C4 (LTC4). Method:Airway epithelial cells and AECOPD airway epithelial cells were cultured. Sixty SPF male SD rats were randomly divided into 6 groups, namely high, medium and low-dose Qingjin Huatantang groups, western medicine group, model group and normal group. Except for the normal group, the remaining groups were included into the AECOPD model by lipopolysaccharide (LPS) tracheal instillation method + fumigation method. After modeling, the dosage of the high-dose traditional Chinese medicine group was 30 g·kg-1·d-1, that of the middle-dose group was 15 g·kg-1·d-1, that of the low-dose group was 7.5 g·kg-1·d-1, the positive control group was given luo erythromycin (0.017 5 g·kg-1·d-1), the model group and the blank control group were orally given normal saline with the volume of 20 mL·kg-1·d-1. Serum was extracted two weeks after administration, and the cells were intervened with drug-containing serum. The content of interleukin IL-1β, TNF-α, and LTB4 in cell supernatants were detected by enzyme-linked immunosorbent assay (ELISA). And LTC4 content, p62 mRNA and protein expressions in lung airway epithelial cells were detected by quantitative real-time fluorescence polymerase chain reaction (Real-time PCR) and Western blot. Result:Compared with the normal group, ELISA results showed that IL-1β, TNF-α, LTB4, and LTC4 in the model group were significantly increased (P<0.01). Compared with the model group, IL-1β, TNF-α, LTB4, LTC4 in cell supernatants in each administration group were significantly reduced (P<0.01), mRNA and protein expressions in p62 showed that compared with the normal group, mRNA and protein expressions in p62 of model group significantly decreased (P<0.01). Compared with the model group, the mRNA and protein expressions of p62 in each administration group significantly increased to different degrees (P<0.01). The expression of autophagy in Qingjin Huatantang high-dose group and western medicine group was comparable. Conclusion:Qingjin Huatantang can reduce the inflammatory response in airway epithelial cells, which may be related to the regulation of autophagy protein p62.

Effect of Qingjin Huatan Tang on COPD of Rat Inflammatory Response by Regulating Autophagy / 中国实验方剂学杂志

Objective: To explore the effect of Qingjin Huatan Tang (QJHTD) on the inflammatory response of chronic obstructive pulmonary disease(COPD) rats by observing the autophagy regulating effect of QJHTD on COPD rats. Method: The 50 SPF grade male rats were randomly divided into 5 groups, with 10 rats in each group. In addition to the normal group, the remaining 40 male rats were randomly divided into 5 groups. After the establishment of the hematoxylin and eosin(HE) staining identification model, the drugs were given to the 5 groups by gavage for 2 weeks, high and low-dose QJHTD groups were give the drug at 30, 10 g·kg-1. Roxithromycin positive control group was given the drug at 0.017 5 g·kg-1. The model control group and the normal group were given the same volume of normal saline. At 1 h after the last gavage, the rats were put to death to extract the airway, and the expressions of autophagy microtuble-associated protein light chain 3 (LC3),Beclin-1 were detected by Real-time quantitative PCR (Real-time PCR) and Western blot. Changes of inflammatory cytokines interleukin-6 (IL-6) and interleukin-8(IL-8) were detected by enzyme linked immunosorbent assay (ELISA). Result: Real-time PCR analysis showed that compared with the normal group, Beclin-1 and LC3 mRNA expressions of autophagy factors in the model group were increased to varying degrees(PPPPPConclusion: QJHTD can alleviate the bronchial inflammation in COPD rats, and its mechanism may be related to the inhibition of autophagy in airway epithelium by QJHTD.

Investigation on microbial contamination of infant formula powder during production process / 中国食品卫生杂志

Objective The aim of this study was to investigate the microbial contamination situation in infant formula powder during the processes of production.Methods A total of 880 samples were collected from Gansu Province,which included raw materials,manufacturing facilities,personnel swabs and final infant formula powder.The detection method conducted in this study were complied with the standard of the SN/T 0738-1997 and GB 4789,and the microbial species detected in this study included Enterobacteriaceae,Enterobacter sakazakii,and Bacillus cereus.Results The detection rate of Enterobacteriaceae was 28.41％ (250/880),the detection rates of Enterobacter sakazakii and Bacillus cereus were 0.46％ (4/872) and 16.94％ (31/183) respectively.The prevalence of Enterobacteriaceae (40.00％,40/100) was the highest in raw materials.Four Enterobacter sakazakii strains were isolated from the pretreatment workshop,equipment and environment surface.The prevalence of Bacillus cereus was 22.73％ (10/44) in final product.Conclusion The microbial contamination was existent widely in infant formula powder and the production procession.Rigid laws and managements should be conducted to reduce the microbial contamination in raw materials,production processes and the environment,which might improve the quality of infant formula powder.

Detection of the Urinary Biomarkers PYD, CTX-II, and DPD in Patients with Kashin-Beck Disease in the Qinghai Province of China / 生物医学与环境科学（英文）

Kashin-Beck disease (KBD) is an endemic degenerative osteoarthropathy of uncertain etiology. The aim of our study was to identify changes in C-telopeptide of type II collagen (CTX-II), pyridinoline (PYD), and deoxypyridinoline (DPD) among KBD patients. 54 KBD patients and 78 healthy controls were included this study. Urinary samples were collected and measured by ELISA. The median quantities of PYD, CTX-II, and DPD of KBD patients were 1107.73 ng/μmol.cre, 695.11 ng/μmol.cre, and 1342.34 pml/μmol.cre, while the median quantities of healthy controls were 805.59 ng/μmol.cre, 546.47 ng/μmol.cre, and 718.15 pml/μmol.cre, respectively. The differences between KBD patients and healthy controls were statistically significant (Z = 4.405, 3.653, and 3.724; P < 0.001). The higher levels of PYD, CTX-II, and DPD detected in KBD patients indicate that they could be used as biomarkers of KBD.

Analysis of risk factors for anastomotic infectious complications following bowel resection for Crohn disease / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the risk factors for anastomotic infectious complications after bowel resection in patients with Crohn disease.</p><p><b>METHODS</b>Clinical data of 124 patients with Crohn disease undergoing bowel resection between January 1990 and October 2012 were analyzed retrospectively. The risk factors were identified by χ(2) test and Logistic regression.</p><p><b>RESULTS</b>Fourteen patients (12.3%, 14/114) developed anastomotic infectious complications in the postoperative period, including anastomotic leak (n=7), intra-abdominal abscess (n=6), and enterocutaneous fistula (n=1). Crohn disease activity index (CDAI)>150 (OR=2.185, 95%CI:1.098-6.256, P=0.040), steroid usage (OR=2.674, 95%CI:1.118-8.786, P=0.027), and the presence of preoperative abscess/fistula (OR=3.447, 95%CI:1.254-10.462, P=0.014) were identified as independent risk factors of anastomotic infectious complications. In the absence of these 3 risk factors, the rate of anastomotic infectious complication was 5.7% (3/53), which increased to 11.4% (4/35) when one risk factor was present, 21.1% (4/19) when two risk factors were present, and 42.9% (3/7) when all the 3 risk factors were present.</p><p><b>CONCLUSIONS</b>CDAI>150, steroid usage and preoperative abscess/fistula are associated with higher rates of anastomotic infectious complications following bowel resection for Crohn disease. A prudent management should be carried out if risk factors can not be eliminated preoperatively.</p>

Diagnostic value of Crohn disease activity indices in assessing postoperative recurrence / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the diagnostic value of Crohn disease activity indices (CDAI) in assessing symptomatic recurrence following ileocolic resection for Crohn disease.</p><p><b>METHODS</b>A total of 85 patients who underwent ileocolic resection between March 2003 and March 2010 were included. Clinical and endoscopic evaluation were performed within 12 months after operation. Endoscopic appearance was assessed using Rutgeers score and endoscopic recurrence was defined as endoscopic score ≥i2. Symptomatic recurrence was defined by the composite of symptom severity warranting medical therapy and endoscopic recurrence. The receiver operator characteristic (ROC) curve was used to explore the utility of CDAI in determining the presence or absence of symptomatic disease.</p><p><b>RESULTS</b>Nineteen patients had symptomatic recurrence within 12 months postoperatively. The mean CDAI of patients with symptomatic recurrence was 205±93, significantly higher than those with sustained remission(97±44, P<0.01). The area under the ROC curve for symptomatic recurrence and CDAI was 0.786. Symptomatic recurrence was best predicted by a CDAI cutoff of 150 and the sensitivity, specificity, and accuracy was 73.7%, 81.8% and 80.0% respectively. When a combined endoscopic and CDAI was applied, the specificity and accuracy was markedly improved to 95.5% and 90.6%. In comparison to CDAI alone, the combined use of CDAI and endoscopic evaluation had a higher level of agreement on symptomatic recurrence(Kappa value, 0.718 vs. 0.462).</p><p><b>CONCLUSIONS</b>CDAI is effective to predict symptomatic recurrence. A combination of CDAI and endoscopic evaluation can further improve the accuracy of assessing symptomatic recurrence.</p>

Effects of short-term forest bathing on human health in a broad-leaved evergreen forest in Zhejiang Province, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the effects of short-term forest bathing on human health.</p><p><b>METHODS</b>Twenty healthy male university students participated as subjects and were randomly divided into two groups of 10. One group was sent on a two-night trip to a broad-leaved evergreen forest, and the other was sent to a city area. Serum cytokine levels reflecting inflammatory and stress response, indicators reflecting oxidative stress, the distribution of leukocyte subsets, and plasma endothelin-1 (ET-1) concentrations were measured before and after the experiment to evaluate the positive health effects of forest environments. A profile of mood states (POMS) evaluation was used to assess changes in mood states.</p><p><b>RESULTS</b>No significant differences in the baseline values of the indicators were observed between the two groups before the experiment. Subjects exposed to the forest environment showed reduced oxidative stress and pro-inflammatory level, as evidenced by decreased malondialdehyde, interleukin-6, and tumor necrosis factor a levels compared with the urban group. Serum cortisol levels were also lower than in the urban group. Notably, the concentration of plasma ET-1 was much lower in subjects exposed to the forest environment. The POMS evaluation showed that after exposure to the forest environment, subjects had lower scores in the negative subscales, and the score for vigor was increased.</p><p><b>CONCLUSION</b>Forest bathing is beneficial to human health, perhaps through preventive effects related to several pathological factors.</p>

Value of quantitative examination via contrast-enhanced ultrasonography in evaluating the activity of Crohn disease at endoscopy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the predictive value of quantitative examination via contrast-enhanced ultrasonography on the activity of Crohn disease at endoscopy.</p><p><b>METHODS</b>A total of 59 cases with Crohn disease in People's Hospital of Lishui City between January 2009 and December 2010 were collected prospectively and underwent both colonoscopy and contrast-enhanced ultrasonography. According to the Simple Endoscopic Score, Crohn disease was divided into inactive and active disease by colonoscopy. To assess the vascularization of the involved bowel loop in a region expected to be seen at colonoscopy, the contrast agent uptake was measured by using quantitative analysis. Measurement of contrast enhancement was assessed as the percentage of increase in wall brightness in regions of interest (ROI). The receiver operating characteristic curve was used to evaluate the value of contrast agent uptake in predicting the severity determined at endoscopy.</p><p><b>RESULTS</b>Colonoscopy showed active lesions in 45 cases and inactive lesions in 14 cases, in whom the percentages of increase of brightness were (90±32)% and (41±29)% respectively. At a threshold value of 45% for the percentage of increase of brightness, sensitivity, specificity and accuracy of predicting the severity at endoscopy were 95.6%, 78.6% and 91.5%, the Youden index was 0.74, and area under curve was 0.846.</p><p><b>CONCLUSIONS</b>Quantitative measurement of bowel enhancement by using contrast-enhanced ultrasonography can discriminate between active and inactive Crohn disease at endoscopy. Contrast-enhanced ultrasonography may be a useful technique to monitor the activity of Crohn disease.</p>

Endemic fluorosis in Guide county of Qinghai province in 2008: an analysis of surveillance results / 中国地方病学杂志

Objective To investigate the prevalence of endemic fluorosis in Guide county of Qinghai province, in order to provide appropriate measures to monitor and control the disease. Methods Damo, Wenquan, Baoning villages(water source has been changed) and Taiping village(water source has not been changed) in Guide county were involved in the study in 2008. One tap water sample was collected in dry and rainy seasons, respectively. Water fluoride was tested in accordance with the "Standard Test Methods for Drinking Water" (GB/T 5750.5-2006); of all the children aged 8 to 12, dental fluorosis was diagnosed using Dean criteria; 6 copies of urine samples were collected in each age group, urinary fluoride was measured using fluoride ion-selective electrode (WS/T 89-1996). According to the "Clinical Diagnostic Criteria of Endemic Skeletal Fluorosis "(WS 192-2008), clinical skeletal fluorosis was determined in adults over the age of 16 by X-ray examination for 10 people in each selected village. Results The mean water fluoride was 0.58,0.38,2.28,0.37 mg/L in Damo, Wenquan, Taiping, and Baoning villages, respectively, and that of Taiping village exceeded the national standard(1.0 mg/L). One hundred and ninety-three children aged 8-12 were checked, the detection rate of dental fluorosis was 49.74% (96/193); urine samples of 116 children were tested, median urinary fluoride was 1.49 mg/L A total of 1503 adults over the age of 16 were examined, the clinical detection of skeletal fluorosis was 51.63%(776/1503); a total of 82 people were X-rayed, X-ray detection of skeletal fluorosis was 20.73%(17/82). The characteristic of X-rays were degeneration and ossification of interosseous membrane. Conclusions Prevalence of dental fluorosis of children and adult clinical skeletal fluorosis are higher. The endemic fluorosis is still comparatively serious. Prevention efforts need to be further strengthened.

Endemic fluorosis in Huangyuan county Qinghai province in 2009: an analysis of surveillance results / 中国地方病学杂志

Objective To investigate the prevalence change of drinking water type of endemic fluorosis and the effect of control measures implemented in Huangyuan county of Qinghai province. Methods In 2009, all the endemic fluorosis villages in Huangyuan county were divided into two degrees, light and medium, according to the water fluorosis content before implementing the improving water project, 1 to 2 villages were selected from each degree village, respectively,as monitoring sites, and a total of 3 villages were selected. Source water and tap water samples were collected from each village and water fluoride concentration was determined. Dental fluorosis of all children aged 8 to 12 of monitoring villages was examined, and urine samples were collected by age group of children for determination of urinary fluoride. Clinical skeletal fluorosis of adults over 16 years of age was examined, and 20 copies of adults urine samples were collected to determine urinary fluoride. One village was selected in the 3 villages monitored to conduct X-rays examination of skeletal fluorosis. Water fluoride was tested in accordance with the "Non-metallic Targets Test Methods for Drinking Water" (GB/T 5750.6-2006); urinary fluoride was tested by fluoride ion-selective electrode method (WS/T 89-1996); dental fluorosis was diagnosed using Dean method;adult skeletal fluorosis was diagnosed by "Clinical Diagnostic Criteria for Endemic Skeletal Fluorosis"(WS 192-2008). Results Twelve water samples were assayed, water fluoride was (0.35 ± 0.43) mg/L. The detectable rate of dental fluorosis of 122 children aged 8-12 was 34.43%(42/122) and the geometric mean urinary fluoride was 0.89 mg/L of the 96 children. Of the 834 adults aged 16 and over, clinical detection of skeletal fluorosis was 47.72% (398/836) and geometric mean urinary fluoride was 1.10 mg/L of the 65 cases of adult urine samples assayed, detection rate of X-rays was 31.4% (11/35) in Gangou village of the 35 adults examined.Conclusions In Huangyuan county, water fluoride of the 3 surveyed villages are normal but the endemic fluorosis is still serious. It should strengthen monitoring and analyze the causes and improve prevention measures.

Analysis of surveillance results of drinking water type of endemic fluorosis in Qinghai province in 2009 / 中国地方病学杂志

ObjectiveTo investigate the development trend of drinking water type of endemic fluorosis in Qinghai province, and to provide the basis for the prevention and treatment of the disease. MethodsIn 2009, six monitoring counties were chosen by using simple random sampling methods, all diseased villages of the six monitoring counties were classified into light, moderate and severe disease types according to water fluorine content on the historical data, and 1 village was respectively chosen from each type. In monitoring villages with improved water, 3 tap water and one source water samples were collected, respectively. Five water samples were collected randomly in water unimproved monitoring villages according to water well locations of east, west, south, north and center. The fluorine content in water and urine was determined according to the Standard Testing Methods for Drinking Water (GB/T 5750-2006). Children aged 8 to 12 were examined for dental fluorosis by Dean method.Clinical osteofluorosis of all the resident over the age of 16 was examined, 2 village of these counties were randomly selected, and clinically diagnosed patients with skeletal fluorosis were examined again by X-ray using Diagnostic Criteria of Endemic Skeletal Fluorosis (WS 192-2008). Urine sample of 30 children aged 8 to 12 and of 20 adults over the age of 16 were randomly collected and urinary fluoride was determined by F-ion selective electrode method (WS/T 89-2006). ResultsImproving water projects had been implemented in 14 monitoring villages of the 18 villages in 6 counties, the rate of improved-water was 77.78％(14/18). Among the 14 projects, 5 improved-water projects ran normally, and 9 projects ran with intermittently water supply. Seventy-five water samples were tested, themean of water fluoride was 0.48 mg/L. The prevalence of dental fluorosis was 31.95％ (285/892), that of clinical skeletal fluorosis was 36.55％(1570/4295) and the X-ray detection rate of skeletal fluorosis was 25.64％ (20/78).Five hundred and seventy-one urine samples of children were determined, and geometric mean of urinary fluorine was 1.04 mg/L; 370 adult urine samples were determined, and geometric mean of urinary fluorine was 1.52 mg/L Conclusion Epidemic of drinking water type of endemic fluorosis is still serious in Qinghai province, and drinking water defluoride measures should be further strengthened and improved.

Inhibition of malignant phenotype of HeLa cells by RNA interference of the telomerase activity / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the biology of HeLa cells upon inhibition of human telomerase catalytic subunit (hTERT) gene by RNA interference in vitro.</p><p><b>METHODS</b>Four shRNAs (A, B, C and D) targeting hTERT gene were designed and prepared by in-vitro transcription. The expression of hTERT gene was evaluated by immunofluorescent staining and telomeric repeat amplification protocol (TRAP) ELISA (TRAP-ELISA), after transient transfection of shRNAs by lipid formulation. Through the initial selection, shRNA (B) was noticed as the most efficient one in down-regulating hTERT gene and therefore was chosen as the ultimate shRNA used in the experimental groups. Those transfected by non-silencing RNAi were chosen as the control groups. Cell spreading and migration were studied by microscopy and cell adhesion to fibronectin (FN) was assayed by cell counting kit-8 (CCK-8). Cell invasion was assessed by Boyden chamber assay.</p><p><b>RESULTS</b>Cell spreading study revealed that the rates of spreading cells in the experimental groups were (5.6 +/- 2.3)% at 30 min, and (26.3 +/- 6.1)% 2 h after the inoculation, respectively, whereas the rates of spreading cells in the control groups were (31.3 +/- 7.9)% and (79.4 +/- 4.8)%, respectively. There were significant differences between the two groups (P < 0.01). However, most of the cells in both groups became spreading after 24 h. Cell adhesion assay demonstrated that the rate of adhesion cells on FN in experimental groups was (67.2 +/- 2.8)%, less than that in control groups (83.7 +/- 5.4)% (P < 0.05). The relative migration distance was (27.1 +/- 6.2)% in the experimental group, lower than that of the control group (58.7 +/- 15.0)%. The invasion assay revealed that the invading cells were 75.7 +/- 14.5 in the experimental group, in contrast to 165.1 +/- 11.0 in the control group after 4 h incubation on matrigel. The difference between these two groups was significant (P < 0.05).</p><p><b>CONCLUSION</b>In vitro shRNA silencing of hTERT gene can down-regulate the telomerase activity, leading to an inhibition of the malignant phenotype of HeLa cells, including decreased ability of cell spreading and adhesion, reduction of cell migration, and declined invasive ability through Matrige assay.</p>

Analysis on the prevention and treatment of drinking water fluorosis Guide county, in Qinghai province / 中国地方病学杂志

Objective To observe the state of endemic flurosis, construction and running status of water improvement projects in order to provide a scientific basis for prevention and treatment fluorosis. Methods Water samples of the diseased and nondiseased villeges were collected from east, west, south, north and centre of each villege in 2005, and fluoride concentration was determined for each surveyed village with unimproved-water. At the same time, all the tap water and source water samples were collected to determine fluoride concentration in each water-improved village surveyed. In 2008, all the endemic fluorosis villages in Guied county were divided into slight, medium and heavy types according to the water fluoride content before water improved, and 1,1,3 survey villages were chosen from each type. In all of the village children aged 8 to 12 years were tested for dental fluorosis by Dean method. Six copies of the urinary fluoride were sampled in different age groups. The fluorine content in water and urine was determined by F-ion selective electrode. The situation of clinical skeletal fluorosis of adults over 16 years of age was investigated, 20 adults (evenly divided between men and women) in the villages of medium and heavy types were examined by X-ray for skeletal fluorosis. Results In 3 village fluoride content of drinking water exceeded the national drinking water standards ( <1.0 mg/L) of 85 surveyed villages with improved-water. Among the 16 projects, 8 were intermittently running and 3 were retired, leaving only 31.25% of the projects active. Theprevalence of enamel fluorosis was 41.13%( 116/282), that of skeletal flurosis was 47.95%(969/2021) and that of X-ray checked was 20.73% (17/82). The median of urine fluoride was 1.06 mg/L and the scope was 0.20 - 9.44 mg/L.Conclusions Most of the improved-water projects do not normally supply water in the disease ward of Guide county. Therefore, there is an increasing trend of the disease, so further control measures are needed.

Morphologic Localization and Purified Cultivation of Sinoatrial Nodes Isolated from Newborn Rabbits / 实用儿科临床杂志

Objective To localize the sinoatrial node (SAN) of the newborn rabbits in vivo and cut it for purifying cultivation and study the morophologic characters of primary cultured pacemaker cells of SAN under light microscope and transmissional electron microscope. Methods Hearts of the newborn rabbits were embedded in paraffin for HE-staining and observed the location, form of SAN under optical microscope; SAN cells isolated from neonatal rabbits cultured and purified with the method of differential attachment and BrdU-treatment.Results SAN localized in the anterior wall of the superior vena cava and the posterior-lateral atrial wall.There was about 0.32 mm between its lowest point and sulcus terminalis. Three distinctly different types of cells were observed among the cultured cells of SAN: spindle, araneiform and polygon. The spindle cells covered the greatest proportion of the cultured cells of SAN (59.6%?7.3%). The frequency of spontaneous contraction of spindle cells was the highest among the constrcting cells (145 ?9)time/min. The results of ultrastructure observation showed that myofibrils and other organelles in spindle cells were poorly organized and significantly decreased in number compared with araneiform cells. There was no significant difference between araneiform cells isolated from SAN and from atrial muscle.Conclusion Among the cultured cells from neonatal rabbits SAN, the spindle cells are the pacemaker cells of SAN.