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R Du

Publications and source records attributed to R Du.

At least 55 records · Page 3Linked to original sources
PubMed1998

Alpha-1 adrenergic receptors in liver plasma membranes of cirrhotic patients with portal hypertension: a quantitative study.

OBJECTIVE: To investigate the changes of alpha-1 adrenergic receptors in cirrhotic liver and the relationship between the changes and the pathogenesis of portal hypertension. METHODS: The concentration and affinity of alpha-1 adrenergic receptors in the liver plasma membranes of posthepatitic cirrhotic patients with portal hypertension were quantitatively measured using radioligand binding analysis. RESULTS: Compared with 8 controls without hepatic pathological changes, the maximal binding capacity (Bmax) of 9 posthepatitic cirrhotic patients decreased (129.1 +/- 12.0 vs 142.1 +/- 14.1 fmol/mg protein, P > 0.05), dissociation constant (Kd) values increased (0.3945 +/- 0.0974 vs 0.2382 +/- 0.0548 nmol/L, P < 0.01), and the receptor maximal content (RMC) decreased (417.4 +/- 76.8 vs 739.9 +/- 167.6 fmol/g liver, P < 0.01). CONCLUSIONS: The decreased concentration and affinity of alpha-1 adrenergic receptors may play an important role in the metabolic disturbances of catecholamines often seen in some cirrhotic patients, and have implications in the pathogenesis of portal hypertension.

Adult↗
PubMed1998

[Clinical observation of splenectomy on chronic idiopathic thrombocytopenic purpura in 63 patients].

OBJECTIVES: To investigate the effectiveness of splenectomy in patients with idiopathic thrombocytopenic purpura who failed to respond to conservative management. METHOD: Sixty-three patients were treated with splenectomy and followed up for 2 months to 16 years (average 4.7 years). RESULT: The patients had symptoms of bleeding and their platelet count on average was 24 x 10(9)/L. The first, 3rd, 5th and 7th day after operation, the average platelet count was 110 x 10(9)/L, 202 x 10(9)/L, 251 x 10(9)/L and 246 x 10(9)/L. Their platelet recovered to normal during a week in 51 cases (80.9%). The total effective rate was 86.9% after follow-up for 2 months. The recurrence rate was 17.9% in 39 cases after follow-up for longtime. CONCLUSIONS: The curative effect of splenectomy is better in children than in adults. In patients with increased platelet have a favourable prognosis. Splenectomy is safe and effective in the treatment of idiopathic thrombocytopenic purpura.

Adolescent↗
PubMed1998

[Portacaval shunt with H-grafts of small diameter in treating cirrhotic patients with portal hypertension].

OBJECTIVE: To evaluate the effectiveness of portacaval shunt with H-grafts of small diameter in the treatment of cirrhotic patients with portal hypertension. METHOD: 48 patients cirrhotic with portal hypertension were randomized into three groups: portacaval shunt with H-grafts of 8 mm diameter with external ring reinforced (20 patients), proximal splenorenal shunt (17), and side-to-side portacaval shunt (11). The preoperative liver function in Child's grade and the history of variceal bleeding were the same in the three groups. RESULT: The postoperative decrease in portal pressure was comparable in the three groups (0.83 +/- 0.31 kPa, 0.81 +/- 0.50 kPa, and 1.02 +/- 0.45 kPa, P > 0.05). There was no significant difference in postoperative rebleeding rate during the follow-up for 15-28 months, and in hospital mortality between the three groups. However, postoperative encephalopathy developed much less in patients undergoing portacaval shunt with H-grafts than those receiving side-to-side portacaval shunt (5.0% vs. 36.4%, P < 0.05). Postoperative transfemoral portography performed within one month showed shunt patency in 95% of the 20 patients undergoing H-graft shunting. B-mode ultrasonography follow-up of up to 15 months also showed shunt patency in all 19 survivals receiving H-graft shunt. CONCLUSION: This procedure shows less trauma, lower postoperative encephalopathy rate, while as effective in preventing recurrent variceal bleeding as the traditional portosystemic shunt.

Adult↗
PubMed1998

[Intrahepatic portal vein compliance in cirrhosis].

OBJECTIVE: To elaborate the effects of increase in portal flow on intrahepatic vein compliance with isolated perfused cirrhotic model (IPCM). METHOD: Cirrhosis was induced by CCl(4) in 80 Wistar rats, which were divided into two groups A and B, by portal with/without hepato-artery. Portal flow was increased and hemodynamic parameters were recorded and analysed. RESULT: In group A, compared with 1.65 +/- 0.28 kPa at basal control, portal pressure was elevated from 2.55 +/- 0.40 kPa to 3.96 +/- 0.67 kPa. Q(35)-Q(55) flow rates were raised from 35 to 55 ml/min, respectively. A correlation existed between portal flows and pressures (r = 0.985, P < 0.01). The low flow rate of 15 ml/min at Q(15) caused a irreversible model injury. A largest flow rate in IPCM was, less than in IPRL. In group B, no low flow-injury was found. CONCLUSION: Portal vein compliance of liver is decreased markedly in cirrhotic portal hypertension, but hepatic flow is increased. There are likely some compensative relations between portal and hepato-arterial system.

Animals↗
PubMed1998

[Effect of somatostatin on portal and hepatic hemodynamics and portal venous pressure in cirrhotic patients with portal hypertension].

OBJECTIVE: To investigate the effect of somatostatin on hepatic and portal hemodynamics and portal venous pressure in cirrhotic patients with portal hypertension. METHOD: Colorful doppler ultrasonography was used to measure the diameter and maximum hemokinetic velocity of portal vein and hepatic vein before and after intravenous administration somatostatin, and thus their hemokinetic volume was calculated respectively. Among 15 surgical patients, changes of the portal venous pressure were observed via a catheter before and after the administration of somatostatin. RESULT: One hour and 1.5 hour after the administration, the pressure of portal vein significantly decreased from 2.77 +/- 0.26 kPa to 2.42 +/- 0.27 kPa and 2.40 +/- 0.27 kPa, respectively (P < 0.01). The systolic pressure, diastolic pressure and heart rate showed no significant changes. After the administration, the sectional area of portal vein decreased by 7.28% but without significance. The maximum hemokinetic velocity of portal vein significantly decreased by 18.96% (from 19.72 +/- 7.75 cm/sec to 15.98 +/- 7.26 cm/sec, P < 0.01). The mean total hemokinetic volume increased from 1786.22 +/- 926.37 ml/min to 1836.17 +/- 844.24 ml/min, but without significance (P > 0.05). CONCLUSION: Continuous instillation of somatostatin via peripheral vein can decrease the portal venous pressure in cirrhotic patients with portal hypertension. The mechanism may be the decrease of hemokinetic volume caused by the decrease of hemokinetic velocity of the portal vein.

Adult↗
PubMed1998

[Development of an electrode for atrial epicardial mapping].

Procedure of a electrode for atrial epicardial mapping (template electrode) is introduced in this paper. It is easy to made, we can get sharp and clear waveforms and a constant baseline while mapping. If the electrode is connected with computer, it is able to be used for epicardial mapping of atrial arrhythmias, especially atrial fibrillation in real time.

Animals↗
PubMed1997

[Treatment of atrial fibrillation using maze procedure by radiofrequency ablation].

From May 1994 to May 1996, 20 cases of atrial fibrillation were treated by means of Maze procedure by radiofrequenncy ablation, at the same time 19 cases of these patients were complicated with rheumatic heart valve disease and valve replacement operations were perfomned, in the other case atrial septal defect was repaired. Yoshio Kosakai's operation route was adopted in radiofrequency ablation procedure. After operation 16 patients of atrial fibrillation resumed sinus rhythm (80%), in 4 casess of atrial fibrillation sinus rhythm was unsuccessfully restored, two patients remained atrial fibrillation, one patient was of atrial flutter, the other was of nodal rhythm. Short time was needed in radiofrequency ablation Maze procedure, average time increase of aortic clamping was 20.5 minutes, and there was no danger of hemorrhage related to this kinds of Maze procedure. During 7-10 days after operation, there appeared superventricular arrhythmia which might be related to ill-distribution of radiofrequency ablation, and interference of atrial electric activity.

Adult↗
PubMed1997

[Polymorphism of group specific component (Gc) in nine Han subpopulations in China].

Isoelectric focusing (IEF) followed by immunofixation in thin layer polyacrylamide gels (pH4-6) was used to analyse the Gc subtypes of 1841 individuals from nine Han geographically distributed populations in China. The Gc1F gene frequencies in these Han subpopulations from Lanzhou, Huhhot, Harbin, Xi'an, Zhengzhou, Chengdu, Guiyang, Zhangzhou and Harras in Guangdong Province were 0.3905, 0.4333, 0.4193, 0.4146, 0.4182, 0.4035, 0.4045, 0.4381 and 0.4347 respectively; Gc1S were 0.3071, 0.2190, 0.2734, 0.2261, 0.2182, 0.2871, 0.2889, 0.2738 and 0.2764 respectively; Gc2 were 0.2786, 0.3357, 0.2917, 0.3367, 0.3295, 0.2896, 0.3065, 0.2667, and 0.2814 respectively. GcV were 0.0238, 0.0119, 0.0156, 0.0226, 0.0341, 0.0198, 0.0000, 0.0214 and 0.0075 respectively. The results of present study indicated a clear cline of linear change from north to south China in allelic frequency at the Group-Specific Component (Gc) locus among nine Chinese populations. Three alleles, Gc1F, Gc2 and GcV, showed frequencies varying from 0.3905 to 0.4381, from 0.2786 to 0.3367 and from nil to 0.0341, respectively, over these geographical subpopulations. In addition, some rare variant phenotypes of Gc in Chinese populations were discussed.

China↗
PubMed1996

High resolution evoked potential imaging of the cortical dynamics of human working memory.

High resolution evoked potentials (EPs), sampled from 115 channels and spatially sharpened with the finite element deblurring method, were recorded from 8 subjects during working memory (WM) and control tasks. The tasks required matching each stimulus with a preceding stimulus on either verbal or spatial attributes. All stimuli elicited a central P200 potential that was larger in the spatial tasks than in the verbal tasks, and larger in the WM tasks than in the control tasks. Frequent, non-matching stimuli elicited a frontal, positive peak at 305 msec that was larger in the spatial WM task relative to the other tasks. Irrespective of whether subjects attended to verbal or spatial stimulus attributes, non-matching stimuli in the WM tasks also elicited an enhanced P450 potential over the left frontal cortex, followed by a sustained potential over the superior parietal cortex. A posterior P390 potential elicited by infrequent, matching stimuli was smaller in amplitude for both spatial and verbal WM tasks compared to control tasks, as was a central prestimulus CNV. These results indicate that WM is a function of a distributed system with both task-specific and task-independent components. Lesion studies and course temporal resolution functional imaging methods, such as PET and fMRI, tend to paint a fairly static picture of the cortical regions which participate in the performance of WM tasks. In contrast, the fine-grain time resolution provided by imaging brain function with EP methods provides a dynamic picture of subsecond changes in the spatial distribution of WM effects over the course of individual trials, as well as evidence for differences in the activity elicited by matching and non-matching stimuli within sequences of trials. This information about the temporal dynamics of WM provides a critical complement to the fine-grain spatial resolution provided by other imaging modalities.

Acoustic Stimulation↗
PubMed1996

[Serum adrenaline and noradrenaline levels in cirrhosis patients with portal hypertension].

High Pressure Liquid chromatography was used to measure serum adrenaline (E) and noradrenaline (NE) concentrations in 38 portal hypertensive patients, 28 idiopathic hypertensive patients, and 34 controls, respectively. It was found that peripheral E in portal hypertensive patients and controls was 57.5 +/- 37.4 pg/ml and 23.5 +/- 11.2 pg/ml respectively (P < 0.01), and peripheral NE was 451.1 +/- 381.2 pg/ml and 183.0 +/- 83.3 pg/ml (P < 0.01). Compared with controls, peripheral E and NE in idiopathic hypertensive patients were also significantly increased (54.9 +/- 39.9 pg/ml vs. 23.6 +/- 11.2 pg/ml, P < 0.01, and 524.3 +/- 219.9 pg/ml vs. 183.0 +/- 83.3 pg/ml, P < 0.01). E and NE in superior vena cava (SVC), portal vein, and peripheral artery in portal hypertensive patients were also increased, but only the elevation of E in SVC was significant (207.2 +/- 55.4 pg/ml vs. 83.7 +/- 46.7 pg/ml, P < 0.05). Our results reveal significant metabolic disorders of E and NE in portal hypertensive patients, which may play an important role in the pathogenesis of portal hypertension.

Adult↗
PubMed1995

Mapping cognitive brain function with modern high-resolution electroencephalography.

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. While electroencephalography (EEG) provides temporal resolution in the millisecond range, which would seem to make it an ideal complement to other imaging modalities, traditional EEG technology and practice provides insufficient spatial detail to identify relationships between brain electrical events and structures and functions that are visualized by magnetic resonance imaging (MRI) or positron emission tomography (PET). Recent advances overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical information from each subject's MRI, and by correcting the distortion that is caused by volume conduction of EEG signals through the skull and scalp. Along with its ability to record how brains think when performing everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.

Brain↗
PubMed1995

Towards measurement of brain function in operational environments.

In operational environments that demand sustained vigilance or that involve multiple tasks competing for limited attentional resources, continuous monitoring of the mental state of the operator could decrease the potential for serious errors and provide valuable information concerning the ergonomics of the tasks being performed. There is widespread discussion and appreciation of the basic feasibility of utilizing neurophysiological measurements to derive accurate, reliable, rapid and unobtrusive assessments of mental state. However, progress in transitioning this idea into practical applications has been impeded by the fact that at present no convenient, inexpensive and effective means exists to derive a meaningful index of brain activity outside of laboratory settings. In this paper, we review some recent advances in recording technology and signal processing methods that will help overcome this limitation. For example, rapid progress is being made in the engineering of recording systems that are small, rugged, portable and easy-to-use, and thus suitable for deployment in operational environments. Progress is also being made in the development of signal processing algorithms for detecting and correcting recording artifacts and for increasing the amount of useful information that can be derived from brain signals. Finally, results from basic research studies suggest that accurate and reliable inferences about the mental load and alertness of an individual can be derived from neurophysiological measures in a practical fashion. These research and engineering successes suggest that it is reasonable to expect that in the near term a basic enabling technology will be deployed that will permit routine measurement of brain function in operational environments.

Arousal↗
PubMed1995

[Analysis of the causes of recurrence of atrioventricular reentry tachycardia in patients treated with radiofrequency current ablation].

The recurrence rate of atrioventricular reentry tachycardia (AVRT) after radiofrequency current ablation (RFCA) of 124 accessory atrioventricular pathways (AP) in 122 patients were reported and the possible causes of recurrence of AVRT were analyzed. Of the 122 patients, 81 were male, 41 female. The average age of the patients was 46.3 +/- 14.4 (14-71) hears. There were 81 manifest AP in 80 patients, 43 concealed AP in 42 patients. 13 of the 124 AP were located in left anterior wall, 59 left lateral wall, 8 left posterior wall, 10 left posterior interventricular septum. 14 right anterior interventricular septum, 2 mid-septum, 14 righy posterior interventricular septum and 4 right free wall. All patients had no organic heart disease. The total recurrence rate of 124 AP in the 122 patients during a follow-up period of 2-25 (13.5 +/- 7.1) months was 4.03% (5/124), with manifest and concealed AP 1.23% (1/81) and 9.30% (4/43), respectively (P < 0.05); left free wall and interventricular septum AP were 2.5% (2/80) and 7.5% (3/40), respectively (P > 0.05); left and right AP were 3.3% (3/90) and 3.1% (1/32), respectively (P > 0.05). The recurrence time was from 0.5 to 60 (15.4 +/- 25.4) days. The recurrence may be related to inaccurate ablation target site, functional and anatomical characteristics of AP, locations of AP, and insufficient ablation energy, etc. It is suggested that AVRT patients receiving RFCA should be followed up for a certain period.

Adolescent↗
PubMed1995

[The level of serum gastrin and ulceration in cirrhotic patients with portal hypertension].

A higher incidence of gastric and duodenum ulcer was well recognized in patients with liver cirrhosis, but the mechanism has not been fully identified. In this study, serum gastrin, free portal pressure (FPP) were measured in 24 consecutively admitted cirrhotic portal hypertensive patients, and preoperative basic acid output (BAO) was measured in 13 randomized patients. Among the 24 patients, concomitant duodenal ulcers were found in 3 by both gastroduodenoscopy and barium series, and gastritis was found in all patients. It was found that most patients (71%) with liver cirrhosis have a elevated level in serum gastrin, whereas BAO is lower than normal in all patients, and the higher the FPP, the lower the BAO is. We believe that the congestive gastroduodenal mucosal lesion was underlying the ulceration most often seen in patients with portal hypertension.

Adult↗
PubMed1995

[A survey on distribution of red cell blood group systems in naxi and primi ethnic groups].

A survey of distribution of red cell blood group systems, including ABO, MNSs, Rh and P, was carried out on the Naxi and Primi ethnic groups in Yunnan province. The results based on 104 cases in each of the two ethnic groups showed that both Naxi and Primi possessed a high gene frequency r of 0.6082 and 0.6882, respectively, with gene frequency p = q. The gene frequency m of Naxi (0.8509) was found to be very high among the populations studied in China until now, only next to that of Lizu (0.8709). The most common phenotype of Rh system was CcDE- in both Naxi and Primi, with a quite high cDE frequency. No case of Rh negative was observed in the two ethnic groups. The P1 in Naxi approximated to that in Primi. The red cell blood group systems and their genetic distances suggested that the Naxi and Primi was genetically close to ethnic groups of North China, but different from those of South China. This fact suggests that these two ethnics groups originated from the North China.

ABO Blood-Group System↗
PubMed1995

Polymorphism of phosphoglucomutase 1 (PGM1) in five Han subpopulations in China.

PGM1 polymorphism in five Han subpopulations in China was investigated by polyacrylamide gel isoelectric focusing. The frequency of PGM1*1A was 0.6256 for Xi'an Han, 0.5982 for Zhengzhou Han, 0.6429 for Huhhot Han, 0.6232 for Lanzhou Han, and 0.6000 for Hakka in Guangdong Province. There was a north to south cline of PGM1*1A frequency.

Alleles↗
PubMed1994

Distribution of red cell blood groups in Han subpopulations of Inner Mongolia, Gansu and Henan Provinces, China.

Three Han subpopulations, Gansu, Henan, and Inner Mongolia were examined for red cell blood group systems, including ABO, Rh, MNSs, Kidd, Duffy, Diego, and Xg. There was no MS type in Gansu, no SS type in Henan and no MNS and NS types in Inner Mongolia, no CCDE- and CcDEE types in Henan, and no ccDee type in Inner Mongolia. The gene frequencies of S (0.0975) and P1 (0.2584) as well as the MS haplotype frequency (0.0629) in Gansu were the highest, while the Di(a) gene frequency (0.0151) in Henan was the lowest among the subpopulations of Han nationality studied so far. The Xg(a) gene frequency in Henan was 0.6055, the highest value observed in China. The genetic distances and phylogenetic tree of eight Han subpopulations showed that the Han in Henan were closest to the Han in Inner Mongolia, and that the Han in Fujian were closest to the Han in Guizhou among others.

Blood Group Antigens↗