Biomedical subjects

J Bai

Publications and source records attributed to J Bai.

At least 109 records · Page 6Linked to original sources

PubMed1998

Optimization and mechanism of step-leap respiration exercise in treating of cor pulmonale.

The interaction between cardiovascular system and the respiratory system is complicated and may be used for the rehabilitation of the cor pulmonale disease. To study the effects of different breathing mode on the cardiac and pulmonary systems, a mathematical model is established based on the previous work. Using this model, computer simulation experiments are carried out for searching an optimal respiration mode in treating of cor pulmonale disease. Results indicate that the step-leap respiration mode could provide a better assistant to the rehabilitation of the cor pulmonale patients in the sense of increasing coronary flow, reducing pulmonary arterial pressure and reducing the working load for the right heart. This result is also proven by the clinical experiments. This work may suggest that a proper directed respiration exercise can be used in the treatment of cor pulmonale disease.

Algorithms↗

PubMed1998

Design and development of an interactive medical teleconsultation system over the World Wide Web.

The objective of the medical teleconsultation system presented in this paper is to demonstrate the use of the World Wide Web (WWW) for telemedicine and interactive medical information exchange. The system, which is developed based on Java, could provide several basic Java tools to fulfill the requirements of medical applications, including a file manager, data tool, bulletin board, and digital audio tool. The digital audio tool uses point-to-point structure to enable two physicians to communicate directly through voice. The others use multipoint structure. The file manager manages the medical images stored in the WWW information server, which come from a hospital database. The data tool supports cooperative operations on the medical data between the participating physicians. The bulletin board enables the users to discuss special cases by writing text on the board, send their personal or group diagnostic reports on the cases, and reorganize the reports and store them in its report file for later use. The system provides a hardware-independent platform for physicians to interact with one another as well as to access medical information over the WWW.

Internet↗

PubMed1998

Questionnaire items that predict asthma and other respiratory conditions in adults.

The International Union Against Tuberculosis and Lung Disease questionnaire is widely used in epidemiologic studies of adult asthma. We examined whether the symptom questions could be classified into groups that represent different "syndromes," and whether some questions are better for predicting asthma than others. We analyzed questionnaire data from a population sample of 1,527 adults aged 18 to 55 years using factor analyses to classify the 17 respiratory symptom questions into four different groups that we termed asthma, cough, breathlessness, and urgent medical visit. The urgent medical visit was a subset of asthma. These four "syndromes" had good validity when measured against airway responsiveness to histamine, atopy to common allergens, lung function, smoking status, and body mass index. Questions that predicted asthma syndrome were those that asked about wheeze at rest or following exercise, asthma attack, chest tightness, and shortness of breath at rest. Questions about cough identified a different group of subjects who apparently did not have asthma. Questions of breathlessness did not aggregate with "asthma" or with "cough syndrome." The identification of particular questions that measure different respiratory conditions is important for epidemiologic studies when short questionnaires or more precise definitions are required.

Adolescent↗

PubMed1998

Experimental model of renovascular hypertension.

OBJECTIVE: To establish a model of renovascular hypertension. METHODS: A 4/0 resorbable chromic catgut ligature was used to ligate subtotally the renal arteries of 18 dogs, forming experimental renovascular hypertension steadily. Blood pressure, plasma renin activity, the ultrastructural changes of juxtaglomerular apparatus and renal artery wall were studied after the constriction. RESULTS: It was reasonable that renal blood flow measured with an electromagnetic flowmeter was reduced by 30% after the constriction. The pathological changes of the induced renal artery stenosis were similar to those of fibromuscular dysphasia. CONCLUSION: The findings provide valuable evidence for the treatment of renovascular hypertension.

Animals↗

PubMed1998

[The studies on MTS1/p16 gene deletion during transformation of human bronchial epithelial cells].

OBJECTIVE: To detect the deletion of MTS1/p16 and the expression of P16 protein during the transformation of human bronchial epithelial cell line M. METHODS: Dual-color fluo-rescence in situ hybridization (FISH), immunohistochemical staining and western blot analysis were carried out. RESULTS: No deletion of MTS1/p16 gene was found in MP18 cells of the cell line M. But partial deletions occurred in the MP36 and MP120 cells of the cell line M. Immunohistochemical analysis and western blot test showed lower expression of P16 protein in the MP120 cells than in MP20 cells. CONCLUSIONS: MTS1/p16 gene deletion contributes to the malignant transformation of the human bronchial epithelial cell line M. Also FISH is a useful technique in detecting gene deletion.

Bronchi↗

PubMed1998

Overexpression of CuZnSOD gene suppresses the growth of hepatocellular cancer cell line HepG2.

OBJECTIVE: To explore the inhibiting effect of superoxide dismutase (SOD) on the growth of hepatocellular cancer cell line HepG2. METHODS: By gene transfer technique, hepatocellular cancer cells (HepG2) were transfected with a retroviral vector containing human CuZnSOD cDNA. The elevated SOD gene expression of the transfected cells was compared with the parental and neo control cells. RESULTS: Compared to the control cells, cancer cells transfected with SOD gene showed an inhibited cell growth, a reduced number of cells in S phase and decreased clone forming ability in soft agar, as well as a smaller tumor size formed in nude mice. CONCLUSION: The overexpression of CuZnSOD gene could, to certain extent, suppress the cell growth of hepatocellular cancer cell line HepG2.

Carcinoma, Hepatocellular↗

PubMed1998

[Clinical and experimental study on treatment of acute alcohol intoxication with xiangnaojing injection].

OBJECTIVE: To study the therapeutical mechanism of traditional Chinese medicine Xingnaojing injection (XNJI) for acute alcohol intoxication. METHODS: XNJI was used in treating the experimental model rabbits (n = 26) and the patients (n = 8) admitted to the emergency department with acute alcoholism. Before and after the treatment, beta-EP, superoxide anion (free radicals) and SOD were measured. RESULTS: XNJI could enhance the regaining consciousness of rabbits and patients, simultaneously reduce the concentration of beta-EP in plasma to the normal level (drunk rabbits 127.09 +/- 13.67 ng/L, normal rabbits 41.48 +/- 7.46 ng/L. P < 0.01, drunk patients 292.97 +/- 14.85 ng/L, normal people 221.60 +/- 15.95 ng/L, P < 0.01). The concentration change of superoxide anion (free radicals) in plasma of rabbits and patients was similar to beta-EP (drunk rabbits 313.39 +/- 15.64 u/L, normal rabbits 254.27 +/- 21.71 u/L, P < 0.01; drunk patients 278.47 +/- 11.48 u/L, normal people 159.92 +/- 11.51 u/L, P < 0.01), and SOD was inversely changed (drunk rabbits 53.57 +/- 6.48%, normal rabbits 77.18 +/- 7.89%, P < 0.01; drunk patients 43.76 +/- 7.84%, normal people 82.53 +/- 4.33%, P < 0.01). CONCLUSIONS: XNJI is similar to Naloxone in pharmacologic action. And it is an effective antioxidant. It can be used for treating alcoholism.

Adult↗

PubMed1998

[An internet based medical communication server].

The telemedicine and medical conference usually need multi-point to multi-point communication. Because the communication users can be patients, specialists or medical centers, they have different communication ratios and different physical connection, therefore, this kind of communication is complicated and limited by the communication ratios. In this paper, to meet the requirements of medical communication, we presented a concept of medical communication server which is able to receive data packages and deliver them according to the request of clients, and described its implementation in Windows 95 environment by using Windows Sockets.

Computer Systems↗

PubMed1998

A simulation study on +Gz protection afforded by extended coverage anti-G suits.

Computer simulation studies using our newly developed mathematical model of human cardiovascular (CV) system were performed to investigate the effect of bladder coverage and inflation schedule of anti-G suit on G protection and CV response. The simulation results agree well with centrifuge experiments. The study demonstrates that additional +Gz protection provided by the extension of the bladder coverage depends mainly upon the pressure transmission efficiency to the underlying tissues and vessels. Although G tolerance increases clearly with the increase of suit inflation schedule, the tendency of increase seems slower when inflation schedule becomes higher than 10 kPa/G.

Acceleration↗

PubMed1998

[Effects of the glucoprotein component of musk on functions of rat polymorphonuclear leukocytes activated by LTB4 in vitro].

To investigate the effects of musk-1, a glucoprotein component isolated from the water extract of musk, on some functions of rat polymorphonuclear leukocytes activated by LTB4, an in vitro incubation system with rat polymorphonuclear leukocytes was used. The superoxide anion production was determined by cytochrome C reduction, and the beta-glucuronidase and lysozyme release was quantitated by enzyme reactions in which phenolphthaleinglucuronic acid and micrococcus lysodeikticus were used as the substrates. In comparison with the control, musk-1 at final concentrations of 1 microgram/ml-100 micrograms/ml can increase the superoxide anion production by 28.7%-202.1% and decrease the beta-glucuronidase and lysozyme release by 3%-46% and 6%-32% respectively in rat polymorphonuclear leukocytes. It is concluded that musk-1 can significantly affect the functions of rat polymorphonuclear leukocytes activated by LTB4. One of the mechanisms of this anti-inflammatory action of musk may consist in the inhibition of lysosomal enzyme release.

Animals↗

PubMed1998

[Production, identification and redirected cytotoxicity of CD3/CD19 bispecific monoclonal antibody].

OBJECTIVE: To prepare CD3/CD19 bispecific monoclonal antibody (BsAb) and study its biological effects. METHODS: The CD3/CD19 BsAb was prepared by using hybri-hybridoma technique. The presence of BsAb was demonstrated by double-isotype ELISA and cell conjugate assay. RESULTS: We obtained three strains of CD3/CD19 quadromas, including a stable one. 51Cr release assay showed that CD3/CD19 supernatants, CD3/CD19 purified antibody and CD3/CD19 chemical heterocongjugate greatly enhanced the cytotoxic activity of CD3 AK cells against Nalm-6 cells (P < 0.05-0.001). CONCLUSIONS: The CD3/CD19 BsAb we prepared was efficient in redirecting activated T cells against target tumor cells. This indicates that the CD3/CD19 BsAb has potential value of clinical use.

Animals↗

PubMed1998

[Cell density and expression of proliferating cell nuclear antigen (PCNA) in the lens epithelium of children and aging patients with cataract].

OBJECTIVE: To determine the cell density and expression of proliferating cell nuclear antigen (PCNA) in the lens epithelium of children and aging patients with cataract. METHODS: The lens epithelial cells (LECs) of the central area were examined in two groups, children (less than 12 years old) and senile persons (51 - 80 years old). The densities of LECs in the two groups were calculated with samples stained with hematoxylin and eosin (HE) staining, and the PCNA was tested immunohistochemically. The integral optical density (IOD) of PCNA expression was measured through a medical color image analysis system. RESULTS: The densities of LECs in children and senile persons were 5,020.25 +/- 246.01 cells/mm(2) and 4,340.00 +/- 240.95 cells/mm(2) (P < 0.05), the IODs were 2.89 +/- 0.57 and 2.13 +/- 0.63 (P < 0.05) respectively. CONCLUSION: The LEC counting and IOD values in children eyes are significantly higher than that of senile persons, suggesting that they be one of the important factors in the formation of posterior capsular opacification (PCO) or after cataract in children eyes.

Aged↗

PubMed1998

[Physical simulation of radial artery displacement].

A previous developed physical cardiovascular simulation is used to investigate the displacement of radial artery during a cardiac cycle. Simulation result shows that the displacement is much greater than the change in the radius of the radial artery. The result is similar to the clinical observation reported before. Based on the simulation result, it is suggested that the displacement of radial artery plays an important part in the Maixiang (pulse condition), which is one of the most important contents of diagnostics in Traditional Chinese Medicine.

Cardiovascular Physiological Phenomena↗

PubMed1998

[A methodological study on the detection of myocardial ultrasonic integrated backscatter].

The cyclic fluctuation of ultrasonic integrated backscatter(IB) of myocardium has been found to be a potential indicator of clinical significance in the diagnosis of myocardial ischemia. To investigate the feasibility of such a technique, a clinical IB testing system is established in our laboratory. Six male subjects with no history of heart diseases were tested by using this system. Based on the clinical data obtained during the tests, the effects of echo position, bandwidth, and different calculation algorithms on IB value were analyzed and compared. The results are available to provide a guideline for the design of instrumentation for IB detection.

Adult↗

PubMed1997

Measurement of spontaneous transfer and transbilayer movement of BODIPY-labeled lipids in lipid vesicles.

An assay was developed to study the spontaneous transfer and transbilayer movement (flip-flop) of lipid analogs labeled with the fluorescent fatty acid, 5-(5,7-dimethyl BODIPY)-1-pentanoic acid (C5-DMB-) in large unilamellar lipid vesicles comprised of 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC). The assay is based on the concentration-dependent changes in fluorescence intensity that occur when donor vesicles containing a C5-DMB-lipid are mixed with nonfluorescent acceptor vesicles. A kinetic model was developed to describe the time-dependent changes in concentration of a lipid undergoing both spontaneous transfer between unilamellar vesicles and transbilayer movement within the vesicle membranes, and a mathematical solution was obtained. Data were obtained using C5-DMB-labeled analogs of sphingomyelin (C5-DMB-SM), ceramide (C5-DMB-Cer), phosphatidylcholine (C5-DMB-PC), and diacylglycerol (C5-DMB-DAG), and kinetic parameters for each lipid were determined using a nonlinear least-squares fitting program. The half-times for interbilayer transfer of the lipids were C5-DMB-SM (21 s) < C5-DMB-PC (350 s) approximately C5-DMB-Cer (400 s) << C5-DMB-DAG (100 h). C5-DMB-Cer (t1/2 approximately 22 min) and C5-DMB-DAG (t1/2 approximately 70 ms) exhibited rapid spontaneous transbilayer movement, while C5-DMB-SM (t1/2 approximately 3.3 h) and C5-DMB-PC (t1/2 approximately 7.5 h) moved across the bilayer very slowly. These results provide a basis for interpreting the behavior of these lipid analogs in cells.

Boron Compounds↗

PubMed1997

First trial of home ECG and blood pressure telemonitoring system in Macau.

OBJECTIVE: To determine the feasibility of home monitoring of patients with cardiac disease or hypertension. METHODS: An improved home electrocardiographic and blood pressure telemonitoring system linked to a central workstation was tested in 10 patients in Macau for 3 months. RESULTS: The total number of connections was 1377. Of the automatic alarm connections, 32.5% were false positive, with the percentage of false positives ranging from 7.6 to 54.6 for different patients. Both patients and physicians found the system easy to use. CONCLUSIONS: Further investigation is required to match the number of patients with the system capacity. A more robust dysrhythmia detection algorithm is needed to reduce the number of false alarms. Nevertheless, the results were sufficiently good that the trial is being expanded.

Blood Pressure Determination↗

PubMed1997

A communication server for telemedicine applications.

The telemedicine applications, in some cases, need multipoint-to-multipoint communication. To meet the requirement of telemedicine communication, the development of a medical communication server is proposed in this paper. To make a working, as well as cost-effective, communication platform for the telemedicine applications, a specially designed communication server model is proposed in this work. This server is able to provide an effective multipoint-to-multipoint communication service for any level applications in telemedicine. The implementation program of this server is developed in a Windows'95 environment by using a winsocket. The trial application testing in a telemonitoring system is also presented to demonstrate the feasibility of taking such a structure with the server. By using the architecture of such a communication server in telemedicine applications, the multipoint-to-multipoint communication is easily managed and the communication processes are simplified and well controlled by the server.

Blood Pressure Monitoring, Ambulatory↗

PubMed1997

A home electrocardiography and blood pressure telemonitoring system.

A home electrocardiography (ECG) and blood pressure telemonitoring system for cardiac patients was installed in the Macau region. The monitoring centre was established in the emergency unit at the Government Hospital of Macau. The first users were 10 cardiovascular patients selected by a physician. The average age of these users was 61 years (range 30-78). The results of a three-month trial showed that the system was easy to operate and technically reliable. It was found to be helpful for cardiac patients. The most significant problem during the trial was electrical noise from the ECG electrodes.

Adult↗