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Biomedical subjects

T F Wang

Publications and source records attributed to T F Wang.

54 records · Page 3Linked to original sources

Effects of paweiwan on streptozotocin-induced hyperglycemia in rats.

The ancient Chinese remedy of Paweiwan was used by patients with polyuria, polydipsia, and polyphagia. The present study investigated the hypoglycemic effects of Paweiwan using streptozotocin-induced hyperglycemic rats. The effects on serum glucose in a 4-day course, in a 7-week course, on the standard oral glucose tolerance test, and on the liver glycogen content were studied. In the glucose tolerance test, chlorpropamide and insulin were used as the positive controls and 0.5% CMC (Carboxymethylcellulose) was used as the negative control. We found that Paweiwan decreased the baseline glucose concentration, ameliorated the blood glucose elevation after glucose challenge, and increased liver glycogen content. The results may imply that Paweiwan increases glucose entrance into cells.

Animals↗

Use of chemically purified and cross-linked bovine pericardium as a ligament substitute.

This study tested the reaction of a periarticular tissue to implanted pericardial membrane, substituting a segment of patellar ligament. Bovine pericardium was chemically purified and cross-linked with monomeric glutaraldehyde under pH, temperature and time conditions minimizing the polymerization of the cross-linking agent. Eight rats had both knee joint patellar ligaments excised. One side served as a control (simple suture), the other dissected ligament was replaced with a strip of pericardium. After 18 days and 12 weeks the dissected ligaments were analyzed by morphological methods. An unexpected fast ingrowth of cells and vessels was observed at 18 days. At 12 weeks new collagen deposits within pericardial patch were seen with striking biodegradation of the implant. Thus, using a new method of cross-linking the collagenous matrix with glutaraldehyde we see no evidence of glutaraldehyde cytotoxicity, as documented by our previous work.

Animals↗

Ring- and N-Hydroxylation of 2-acetylaminofluorene by reconstituted mouse liver microsomal cytochrome P-450 enzyme system.

The N- and ring-hydroxylation of 2-acetylaminofluorene (AAF) are examined with a reconstituted cytochrome P-450 enzyme system from liver microsomal fractions from both control and 3-methylcholanthrene (MC)-pretreated mice. Partial purification of cytochrome P-450 fraction is achieved by bacterial protease treatment of microsomes followed by Triton X-100 solubilization and ammonium sulfate precipitation. Both cytochrome P-450 and NADPH-cytochrome c reductase fractions are required for optimum oxidative activity. Hydroxylation activity is determined by the source of cytochrome P-450 fraction; cytochrome P-450 fraction from MC-pretreated mice is several fold more active than that from controls.

2-Acetylaminofluorene↗

Influence of pacemaker-induced tachycardia with A-V block on left ventricular blood velocity in man.

Phasic instantaneous left ventricular blood velocity was measured by radiotelemetry in 28 subjects with a Doppler ultrasonic flowmeter catheter during atrial pacing and induced A-V block Type I Wenckebach A-V block with conduction ratios of 9:8 or lower generally produced a stepwise reduction of peak left ventricular blood velocity in relation to shortened R-R intervals. Longer Wenckebach periods resulted in little or no blood velocity alteration during 1:1 A-V conduction. Those beats following a blocked atrial depolarization were associated with augmented blood velocities. In three subjects, bigeminal periods of 3:2 A-V block resulted in larger left ventricular blood velocities when compared with 2:1 A-V block, despite identical R-R intervals following the blocked P wave. This latter phenomenon was attributed to diastolic augmentation of left ventricular contraction following the second and hemodynamically ineffective beat during 3:2 A-V block. Three patients manifested true blood velocity alternation during second-degree A-V block and changing R-R intervals. The variations in peak left ventricular blood velocity observed during atrial pacing and A-V block are related to changing inotropic state and cycle length dependent alterations of left ventricular diastolic filling.

Adult↗

Blood velocity at mitral valve during atrial arrhythmias in man.

By means of the Doppler ultrasonic flowmeter catheter, phasic instantaneous left ventricular blood velocity was measured at the mitral valves of 184 conscious human subjects during atrial arrhythmias. Atrial extrasystoles and pacemaker-induced atrial tachycardias reduced peak mitral valve blood velocities in direct relation to shortened diastolic cycle length. Atrial fibrillation with irregular ventricular responses produced beat-to-beat alternations of peak mitral velocity, with smaller peak mitral blood velocities usually associated with shortened R-R intervals on the electrocardiogram. This report represents the first comprehensive description of instantaneous and continous phasic blood velocity at the mitral valve during atrial arrhythmias in man. It is concluded that atrial tachyarrhythmias exert an adverse influence on left ventricular filling velocities.

Adolescent↗

Serum pepsinogen I levels in patients with non-ulcer dyspepsia.

In order to understand whether the serum pepsinogen I (PGI) levels of non-ulcer dyspepsia (NUD) patients differed from those of healthy controls and which kinds of factors might influence these levels of the former, serum PGI levels were determined by radio-immunoassay in 120 healthy controls and 361 NUD patients. The mean serum PGI level was significantly lower in NUD patients than in the controls (75.8 +/- 38.2 ng/mL versus 95.9 +/- 39.3 ng/mL; P less than 0.0001); in NUD patients, it was significantly higher in males than in females (79.6 +/- 40.4 ng/mL versus 63.2 +/- 26.4 ng/mL; P less than 0.001). However, corrected serum PGI levels according to the lean body mass disclosed no sex difference. Nevertheless, there was a weak correlation between the ages of patients and serum PGI levels (r = 0.403). The serum PGI levels in blood groups A, B, AB and O did not differ significantly. Smoking might be a decisive factor, for the mean serum PGI level was significantly higher among the smokers than among the non-smokers (86.7 +/- 44.6 ng/mL versus 70.6 +/- 33.7 ng/mL; P less than 0.001). It is concluded that the mean serum PGI level of NUD patients, while affected by sex, age, smoker status and the body size, is lower than that of the healthy controls. Without endoscopy, assay of serum PGI level has no place in the diagnosis of dyspepsia because of the wide overlapping of serum PGI levels between NUD patients and patients with other common gastric lesions.

Age Factors↗

Prolonged bleeding time in cirrhotic patients: relationship to peripheral vasodilation and severity of cirrhosis.

A prolonged bleeding time (> 540 s), measured with a Simplate single template device, was found in 0% of 50 patients with chronic hepatitis and 38% of 154 cirrhotic patients. Cirrhotic patients with a prolonged bleeding time (n = 59) had lower platelet counts (P < 0.001) and a longer prothrombin time (P < 0.001) and activated partial thromboplastin time (P < 0.001) compared with cirrhotic patients with a normal bleeding time (n = 95). A weak but significant negative correlation existed between the bleeding time and platelet count in cirrhotic patients (n = 154, r = -0.3668, P < 0.001). Patients with decompensated cirrhosis had a longer bleeding time in comparison to patients with compensated cirrhosis (621 +/- 39 vs 478 +/- 27 s, respectively, P < 0.01). The prolonged bleeding time was also discovered in 25% of 83 cirrhotic patients with a platelet count > 80 x 10(9)/L and a prothrombin time < 17 s (usually taken as safe limits for invasive procedures). Twenty-seven of the 83 cirrhotic patients received a haemodynamic study by Swan-Ganz catheterization. A lower systemic vascular resistance was found in cirrhotic patients with an abnormal bleeding time than in cirrhotic patients with a normal bleeding time (844 +/- 57 vs 1171 +/- 60 dyne.s.cm-5, respectively, P < 0.001), whereas both groups had similar hepatic venous pressure gradient (16.2 +/- 1.2 vs 18.1 +/- 1.4 mmHg, respectively, P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Bleeding Time↗