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Biomedical subjects

M J Wang

Publications and source records attributed to M J Wang.

At least 37 records · Page 2Linked to original sources
PubMed2000

[A study on the inheritance of dried tofu output of soybean].

The P1, P2, F1, F2 and F2:3 in plant generation of three crosses of Liuhexiaoyeqing x Xinyixiaohedou, Shangraoganbusi x Huaiyinqiuhedou and Liuhexiaoyeqing x Nannong 73-935 were used to study the inheritance of dried tofu output. The results of the joint analyses of multiple plant generations showed a consistant one major gene plus polygene mixed inheritance model. The heritability values for dried tofu output were as high as 87.84%-99.98%. In plant generation F2:3 of these crosses, the heritabilities of major gene were 51.80%-61.85%, and those of polygene were 36.12%-48.03%. Therefore, both major gene and polygene effects were important and should be utilized in breeding program.

Glycine max↗
PubMed2000

Tetrahydroprotoberberines inhibit lipid peroxidation and scavenge hydroxyl free radicals.

AIM: To study the effects of tetrahydroprotoberberines (THPB) on rat liver and brain lipid peroxidation (LPO) and oxygen free radicals generation. METHODS: The malondialdehyde (MDA) levels in rat brain and liver homogenates, induction of MDA by Fe(2+)-Vit C in mitochondria, OH. generation by Fenton reaction, and O2.- generation by pyrogallol oxidation were observed in vitro. RESULTS: (1) THPB lowered the MDA contents in the liver homogenate and mitochondria, and the IC50 values of l-THPB-18 and l-stepholidine (SPD) in the liver mitochondria were 3.1 and 12.7 mumol.L-1 respectively. SPD decreased the MDA contents in the brain homogenate and mitochondria with IC50 values of 102 and 35.0 mumol.L-1 respectively. (2) THPB scavenged OH., and the IC50 values of l-THPB-18 and SPD were 0.21 and 3.8 mumol.L-1 respectively, but no effect on O2.- was observed. CONCLUSION: THPB could reduce the MDA contents and scavenge OH. and THPB-18 was the most potent amongst them.

Animals↗
PubMed2000

[Studies on pharmacokinetics of chloroquine in mice infected with chloroquine-resistant strain of Plasmodium berghei].

OBJECTIVE: To compare the pharmacokinetic differences of chloroquine in normal mice and the mice infected with the N and the RC strains of Plasmodium berghei. METHODS: The concentrations of chloroquine in the plasma of normal mice and the mice infected with the N or the RC strains of P. berghei were analyzed by reverse-phase HPLC. The pharmacokinetic parameters were measured with software 3P87. RESULTS: The t1/2 beta value was significantly lower in the mice infected with the RC strain than in normal mice and the mice infected with the N strain(P < 0.05), however, there were no significant differences between the mice infected with the N strain and normal mice. CONCLUSION: Elimination of chloroquine in the mice infected with the RC strain of P. berghei speed up significantly comparing with the mice infected with the N strain.

Animals↗
PubMed1999

Rescue for acute myocarditis with shock by extracorporeal membrane oxygenation.

BACKGROUND: Acute myocarditis (AM) complicated with refractory cardiogenic shock carries a very high mortality. We report our experience in treating these patients, who were rescued by extracorporeal membrane oxygenation (ECMO) and intravenous immunoglobulin. METHODS: Over a 5-year period, 5 patients with AM were rescued with ECMO in our hospital. Femoral venoarterial ECMO was performed in 4 patients, and right atrium-left atrium-aorta ECMO in the other 1 due to ventricular dysfunction. Hemofiltration was applied to 3 patients. Marked elevated creatine kinase, its MB form, and troponin T (TnT) were found before ECMO. RESULTS: All the patients could be weaned off the ECMO after 140.0+/-57.7 hours of ECMO support. One patient died of multiple organ failure 10 days later after removal of ECMO, resulting in a 20% mortality. Renal function returned to normal in all survivors. The 4 survivors were discharged uneventfully in 23.3+/-8.3 days and resumed functional class I status. The TnT level declined to the low level within 3 days (slope -4.94+/-1.18 ng/mL/day), and might be an indicator of good recovery of myocardium. CONCLUSIONS: ECMO can provide an effective and simple treatment for critical AM with a satisfactory result and reduce the possibility of progressive cardiomyopathy.

Acute Disease↗
PubMed1999

Differential expression of inducible nitric oxide synthase gene by alveolar and peritoneal macrophages in lipopolysaccharide-hyporesponsive C3H/HeJ mice.

In lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice, alveolar macrophages (AMphi) produce much more tumour necrosis factor-alpha than peritoneal macrophages (PMphi) when stimulated with LPS (10 microgram/ml), but the induction of inducible nitric oxide synthase (iNOS) gene expression and production of nitric oxide (NO) in AMphi are not found. In the present study, we determined the induction of iNOS gene expression, using semi-quantitative reverse transcription-polymerase chain reaction, and the release of NO in AMphi and PMphi from C3H/HeJ and C3H/HeN mice. The results showed the induction of iNOS mRNA accumulation in a dose-dependent manner by LPS alone or in combination with interferon-gamma in both macrophages. The effects of the stimuli on iNOS gene expression and NO production were significantly higher in AMphi than in the PMphi of C3H/HeJ mice. The response of macrophages from C3H/HeN mice was similar to those from C3H/HeJ mice, but the difference of iNOS gene expression between AMphi and PMphi in C3H/HeN mice was not as striking as in C3H/HeJ mice. The results show that the iNOS gene expression and NO production were activated differently in AMphi and PMphi and suggest that the functional properties of macrophages isolated from distinct origins are different.

Animals↗
PubMed1999

Usefulness of intravenous propofol anesthesia for radiofrequency catheter ablation in patients with tachyarrhythmias: infeasibility for pediatric patients with ectopic atrial tachycardia.

General anesthesia is sometimes required during radiofrequency catheter ablation (RFCA) of various tachyarrhythmias because of an anticipated prolonged procedure and the need to ensure stability during critical ablation. In this study, we examine the feasibility of using propofol anesthesia for RFCA procedure. There were 150 patients (78 male, 72 female; mean age 30 years, range 4-96 years) in the study. Electrophysiologic study was performed before and during propofol infusion in the initial 20 patients and was performed only during propofol infusion in the remaining 130 patients. In the initial 20 patients, propofol infusion increased the sinus rate and facilitated AV nodal conduction. The accessory pathway effective refractory period, as well as the sinus node recovery time, atrial effective refractory period, and ventricular effective refractory period were not significantly changed. There were 152 tachyarrhythmias in 150 patients (24 atrial flutter, 31 AV nodal reentrant tachycardia, 68 AV reciprocating tachycardia, 12 ventricular tachycardia, and 17 atrial tachycardia). Most (148/152) tachycardias remained inducible after anesthesia and RFCA was performed uneventfully. However, in four of the seven pediatric patients with ectopic atrial tachycardia, the tachycardia terminated after propofol infusion and could not be induced by isoproterenol infusion. Consequently, RFCA could not be performed. Intravenous propofol anesthesia is feasible during RFCA for most tachyarrhythmias except for ectopic atrial tachycardia in children.

Adolescent↗
PubMed1999

Airway management and transesophageal echocardiographic monitoring for pulmonary artery sling.

Pulmonary artery sling is an uncommon vascular anomaly and can be life threatening when it causes tracheal compression. We report on a 14-day-old boy who presented with respiratory distress soon after birth. A series of examinations showed tracheal stenosis due to a pulmonary artery sling. Surgery was performed with the aid of cardiopulmonary bypass. The external compression and intrisic stenosis could not be resolved by vascular surgery because of tracheal malacia and a complete tracheal ring. We recommend cutting extra holes 1 to 2 cm from the distal end of the endotracheal tube for endobronchial intubation. The airway obstruction was resolved successfully with a custom-made endobronchial tube. However, the patient died of pneumomediastinum and pneumothorax induced by barotrauma, on the fourth postoperative day.

Bronchi↗
PubMed1999

Two genetically selected strains of rats exhibit hypersensitivity or resistance to cocaine-induced fatal arrhythmias.

We identified for the first time two genetically selected strains of rats that differ markedly in sensitivity to cocaine-induced life-threatening cardiac arrhythmias and arrest. The two strains of rats, designated as Fast and Slow, were bred for sensitivity (Fast) or resistance (Slow) to electrically kindled seizures. Studies were performed on halothane-anesthetized, mechanically ventilated rats. Animals were given cocaine (3 or 4 mg/kg/min i.v.) until they died. Arrhythmias (atrioventricular conduction block) developed at much lower cumulative cocaine doses in Slow-kindling rats than in Fast-kindling rats (15 +/- 1 versus 42 +/- 3 mg/kg, p <.01). The lethal cocaine dose (the dose that caused cardiac arrest) was also markedly lower in Slow than in Fast strains (32 +/- 2 versus 62 +/- 6 mg/kg, p <.01). These differences between the two strains were not significantly altered by pretreatment of animals with either ganglionic blockers, hexamethonium (20 mg/kg i.v.) or chlorisondamine (5 mg/kg i.v.), or a nonselective beta adrenergic receptor blocker, propranolol (1 mg/kg i.v.). A nonselective alpha adrenergic receptor blocker, phentolamine (10 mg/kg i.v.), however, abolished the differences between the Fast and Slow strains in the doses of cocaine required to produced atrioventricular conduction block and cardiac arrest. The results provide the first evidence of genetically determined susceptibility or resistance to cocaine-induced cardiotoxicity. There appears to be a genetically determined difference in the alpha adrenergic receptor system between the two strains that is responsible for the differential sensitivity to cocaine-induced arrhythmias and cardiac arrest.

Animals↗
PubMed1998

Cocaine cardiotoxicity differs markedly in isolated hearts of two strains of rats exhibiting phenotypic differences in sensitivity to seizures.

Isolated hearts from two strains of rats bred for sensitivity or resistance to amygdala kindling that also exhibit, in vivo, differential sensitivity to the cardiotoxicity of cocaine were studied. The goal was to determine if the differential cardiotoxic sensitivity was due, at least in part, to intrinsic strain-dependent differences in the heart. The Langendorff preparation was used (n=8 per strain). Hearts were perfused with increasing concentrations of cocaine (5 x 10(-6), 1 x 10(-5), 5 x 10(-5), 1 x 10(-4), and 5 x 10(-4) M) for 5 min with a 5 min washout between exposure to successive concentrations. Consistent with in vivo observations, hearts from genetically slow amygdala kindling rats (Slow) required lower cocaine doses to develop cardiac arrhythmias and arrest as compared to the hearts from genetically fast amygdala kindling rats (Fast). At 5 x 10(-5) M cocaine arrhythmias occurred in 38% (3/8) Slow and 0% Fast hearts. Five of 8 Slow hearts and none of 8 Fast hearts were arrested by 10(-4) M cocaine. Arrest in Fast hearts occurred only with 5 x 10(-4) M cocaine. Cocaine constricted coronary arteries (no significant difference between strains). On the other hand, coronary arteries of Slow but not Fast hearts dilated during cocaine washout after perfusion with all but the highest concentration of cocaine. We conclude that factors intrinsic to the heart and coronary artery influence the sensitivity or response of these structures to cocaine.

Amygdala↗
PubMed1998

The relationship between low back discomfort ratings and the NIOSH lifting index.

An epidemiological study was performed to evaluate the relation between low-back discomfort ratings and use of the revised NIOSH lifting guide to assess the risk of manual material handling (MMH) tasks. We surveyed 97 MMH workers on site in 15 factories and designed a questionnaire to systematically collect job-related information. Approximately 90% of the workers had suffered various degrees of lower back discomfort, and 80% had sought medical treatment. The survey showed that 42 of the 97 jobs analyzed had a recommended weight limit of 0, which was attributed to either a horizontal distance or a lifting frequency that exceeded the bounds of the NIOSH lifting index. Apparently, the limits for horizontal distance and maximum allowable frequency are too stringent to accommodate many existing MMH jobs. For the remaining 55 jobs, the significant positive correlation obtained between the lifting index and the severity of low-back discomfort suggests that the lifting index is reliable in assessing the potential risk of low-back injury in MMH. These findings provide useful information on the application of the NIOSH lifting guide to the assessment of low-back pain.

Adolescent↗
PubMed1997

The activation of human platelets mediated by two monoclonal antibodies raised against CD9.

The platelet activation induced by two anti-human platelet P24/CD9 McAbs was investigated. The results showed that: the pathway of platelet aggregation induced by the two McAbs (HI117 and SJ9A4) is not the same; HI117 and SJ9A4 induced the phosphorylation of platelet proteins (40KD and 20KD) when platelets were activated; but HI117 didn't cause a rise in intracellular Ca2+ concentration in activated platelets compared with SJ9A4; the epitope recognized by HI117 and SJ9A4 is different and this is probably the real reason why the two CD9 McAbs play different roles in platelet activation. Additionally McAbs HI117 and SJ9A4 could not promote associates of other proteins (e.g.: GPIIb/IIIa) with P24/CD9 on activated human platelets. All these results indicate that the mechanism of platelet activation induced by HI117 or SJ9A4 is different form each other. It suggests that CD9 antigen play an important and complex role in platelet activation.

Antibodies, Monoclonal↗
PubMed1997

Land application of sewage sludge in China.

Land application of sewage sludge in China is thoroughly reviewed. Operation of sewage sludge disposal is usually expensive and/or easy to contaminate the environment. In China, most sewage sludge has not been treated and disposed of properly, resulting in environmental pollution and potential exposure to humans. In the near future, sewage sludge production in China will increase rapidly together with the dramatic increase of municipal wastewater treatment ratio (treated/produced), implying that the problem of sewage sludge disposal will become more serious and unavoidable. Proper land utilization of stabilized sewage sludge can make a positive contribution to agriculture, forestry, horticulture and city development. Heavy metals, organic pollutants and pathogens concentrated in sewage sludge during wastewater treatment are the main obstacles to land application of sewage sludge. To promote land application of sewage sludge in China, a statewide survey of sewage sludge production and harmful components in sewage sludge should be carried out. Sewage sludge management and technologies for sludge treatment and disposal suitable to Chinese conditions should be paid more attention.

Agriculture↗
PubMed1997

The influence of gloves during maximum volitional torque exertion of supination.

This study focuses on the influence of friction between gloves and handle surface during maximum volitional torque exertion of supination (S-MVTE) and under both friction-controlled and regular friction conditions. Forty student subjects (20 males and 20 females) participated in this study. Five types of gloves (surgical, single cotton, double cotton, leather, and rubber), seven handle sizes (25.4, 31.8, 38.1, 44.5, 50.8, 57.2, and 63.5 mm in diameter) and two handle shapes (cylindrical and hexagonal) were evaluated to determine their combined influences on S-MVTE. The barehanded condition was also included for comparison. The results indicate that all the main effects were significant (P < 0.001). Under friction-controlled conditions (oiled surface handle), the S-MVTEs with gloves were found to be greater than the S-MVTEs of the gloveless, and the thicker the gloves, the greater the S-MVTE. On the other hand, under regular (unoiled) conditions, the S-MVTE was mainly affected by the friction between handle surface and gloves, although the interaction between gloves and handle shape was also a minor influence. A hexagonal handle produced, in all handle diameters, greater S-MVTE than a cylindrical handle. The mean S-MVTE under oiled conditions was about 53% of that of unoiled conditions. The mean S-MVTE of females was about 61% of that of males.

Adolescent↗
PubMed1997

The effect of valve handwheel type, operating plane, and grasping posture on peak torque strength of young men and women.

An experiment was designed to assess the factors affecting the operation of valve handwheels. Forty volunteers (20 men and 20 women) participated in this study. A nested-factorial experimental design was employed. Handwheel type (smooth, curved, or knurled rim), operating plane (sagittal, frontal, or transverse plane), grasping posture (power or precision grasp), and operating direction (clockwise or counterclockwise) were found to have significant effects on the (maximum volitional torque exertion [MVTE]). A power grasp exerted more force than did a precision grasp. A smooth-rim handwheel oriented in the frontal plane resulted in the least MVTE. Counterclockwise torque exertion was significantly greater than clockwise torque exertion, but the difference was not very large. MVTE for women (7.9 Nm) was about 66% of that for men (12.0 Nm).

Adolescent↗
PubMed1997

Implementing cognitive learning strategies in computer-based educational technology: a proposed system.

Switching the development focus of computer-based instruction from the concerns of delivery technology to the fundamentals of instructional methodology, is a notion that has received increased attention among educational theorists and instructional designers over the last several years. Building upon this precept, a proposed methodology and computer support system is presented for distilling educational objectives into concept maps using strategies derived from cognitive theory. Our system design allows for a flexible and extensible architecture in which an educator can create instructional modules that encapsulate their teaching strategies, and mimics the adaptive behavior used by experienced instructors in teaching complex educational objectives.

Cognition↗
PubMed1996

Efficacy of ultrafiltration in removing inflammatory mediators during pediatric cardiac operations.

BACKGROUND: Conventional and modified ultrafiltration was used in pediatric cardiac operations to reduce volume overload and total body water. The purpose of this study was to compare the efficacy of these techniques in removing inflammatory mediators during cardiopulmonary bypass. METHODS: Fifty pediatric patients undergoing cardiac operations were randomized into a modified or conventional ultrafiltration group. Blood samples were obtained before and after ultrafiltration to assess the plasma concentrations of leukocyte elastase, tumor necrosis factor-alpha, interleukin-6, and interleukin-8. RESULTS: Except for plasma concentrations of tumor necrosis factor-alpha in the modified ultrafiltration group, the plasma concentrations of all the mediators measured increased after ultrafiltration in both groups of patients. The volume of ultrafiltrate and the total amounts of tumor necrosis factor-alpha and interleukin-6 removed by ultrafiltration were significantly greater in the modified group. The concentrations of mediators in the ultrafiltrate and the ratio of ultrafiltrate to plasma concentrations of the mediators did not differ between the groups. Ultrafiltration was more efficient in removing tumor necrosis factor-alpha than the other mediators. CONCLUSIONS: The efficacy in removing the inflammatory mediators generated during cardiopulmonary bypass did not differ between modified and conventional ultrafiltration.

Analysis of Variance↗