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Biomedical subjects

D L Liu

Publications and source records attributed to D L Liu.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Alteration of cocaine, morphine and nicotine levels in serum of opiomaniacs treated by jie du ling].

20 Opiomaniacs were treated by Jie Du Ling consisted of some Chinese herbal medicine. Cocaine, morphine and nicotine levels in serum of 20 cases before and after treatment and 20 subjects for control were measured simultaneously by means of radioimmunoassay. The results showed that cocaine, morphine and nicotine levels in patients serum before treatment were significantly higher than that of control (P < 0.001), while the level of above-mentioned 3 substances in patient's serum after treatment were significantly lower than that of before treatment (P < 0.001). It is proved that Chinese medicinal herbs could significantly reduce the levels of cocaine, morphine and nicotine after treatment in clinical practice. It offered evidence for Chinese herbal medicine in stopping opiomania.

Adolescent↗
PubMed1991

Sound velocity inversion in layered media with band-limited and noise-corrupted data.

With reflection data measured from two different incident angles, it is possible to make them "nearly the same" by stretching or contracting the time axis of one of them. In this way, a correspondence is built up between the two travel times, which can be used to calculate the one-dimensional sound velocity profile of the medium. For the special case that the impulse response of the medium consists of sparse spikes, a spectral fitting procedure is developed which deconvolves the received signal, and gives the exact positions of the spikes. The stepwise sound velocity profile can then be calculated from these positions. In experimental measurements the plane wave assumption made in the analysis is not true, but this can be accommodated with some modifications of the calculation. Results of both computer simulation and of measurements are presented, indicating the validity of these processings.

Computer Simulation↗
PubMed1991

[Determination of D-catechin plasma concentration and pharmacokinetic parameters using HPLC method].

d-Catechin (alpha-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol) is an important hepatotropic drug. It has been extensively used in 1980's. A few methods for quantitative analysis of d-catechin in biological fluids have been reported, but they are not so sensitive or specific for pharmacokinetic interest. In this study, a specific, sensitive and reproducible RPHPLC-DAD method for quantifying d-catechin in plasma is established. Sep-Pak C18 cartridge is used for sample preparation. HPLC separation is performed on Waters HPLC system consisting of a Model 990 diode array detector. A 150 x 5 mm ID column containing YWG C18, held at 25 +/- 0.5 degrees C, and a mobile phase of methanol-0.03 mol/L citric buffer solution containing 0.04% TEMED,pH 4.7 (16:84, v/v) at a flow rate of 2 ml/min is used. Under the studied conditions, the tR for d-catechin is 7.74 min, that of the internal standard (cefetaxime, CTX) is 9.32 min. The peak of d-catechin is identified with the DAD and MS techniques. The limit of detection of the method is 9 ng, and the minimal detectable concentration in plasma is 17.4 ng/ml. There is a linear relationship between the peak area ratio over the range of 69.6-1160 ng/ml with r = 0.9993. The method has been applied to determine the d-catechin concentration in rabbit plasma. The pharmacokinetic characteristics and parameters are studied.

Animals↗
PubMed1989

[Assay of amniotic phosphatidylglycerol and its prospective clinical application].

From January 1985 to August 1987, 184 amniotic fluid specimens were collected from 150 cases of normal and high-risk pregnancies. Using L/S ratio as control, amniotic phosphatidylglycerol (PG) was assayed by modified method of one dimensional, twice run, thin-layer chromatography (TLC). The results were applied prospectively to clinical work. The distance of run for amniotic phospholipids was very consistent. The clinical correspondent rate was 98.67% and was not influenced by either blood or meconium staining. The false negative rate for PG was 1.33%, significantly lower than that of L/S ratio (22.62%). There was no false positive case. All reagents used except standard PG are made in China, but the amount of PG required for each test is minimal. Necessary equipment are simple and local-made. The method is simple and rapid. Therefore, it can be used in any clinical laboratory. So far such method has not been applied clinically in China for prospective study.

Amniotic Fluid↗
PubMed1987

[Midline malignant histiocytosis--diagnostic and prognostic study of 42 patients].

42 patients of midline malignant histiocytosis are reported. The differential diagnosis should be made carefully, for its clinical sign and pathologic picture are similar to some neoplasms, inflammatory or allergic diseases. The 3, 5 and 10 year survival rates are 52.4%, 38.1% and 21.4% respectively. The survival rate of those in the prodromal stage is the highest. The authors suggest that this disease probably belongs to the malignant tumor of mononuclear macrophage system and be a special type of malignant histiocytosis. It may be designated as the midline malignant histiocytosis.

Adult↗