Biomedical subjects

D Li

Publications and source records attributed to D Li.

At least 451 records · Page 25Linked to original sources

PubMed1999

[Portal hypertensive vasculopathy of splenic artery].

OBJECTIVE: To study the pathological changes of splenic artery wall in portal hypertensive patients. METHODS: The pathological changes and iNOS activity of splenic artery wall were studied in 21 patients with liver cirrhosis and 15 normal subjects, using light and electron microscope and immunohistochemistry. RESULTS: Compared with normal individuals, the splenic artery of cirrhotic patients showed that the intima was thickened, split and broken, and the smooth muscle layer of middle membrane was thicker and migrated to underintima space. In cirrhotic patients, regression, atrophy or hypertrophy and hyperplasia were seen in smooth muscle cells whose contractile phenotype changed to synthetic phenotype as well. iNOS activated obviously. Extracellular matrix increased in the wall, resulting in collagenic and fibrous changes. CONCLUSIONS: Hemodynamic alteration due to liver cirrhosis induced pathological changes of splenic artery, including the damage to contractile structure and increase of iNOS activity. It is one of the reasons of decrease of artery reaction to contractile vasoactive materials.

Adult↗

PubMed1999

[Hepatic arterial infusion of 32P-radionuclide microspheres for radiation therapy of hepatocellular carcinoma].

OBJECTIVE: To investigate the efficacy of internal radiation of (32)P-glass microspheres ((32)P-GMS) in unresected hepatocellular carcinoma (HCC) via subcutaneous arterial port. METHODS: Hepatic arterial (99)technetium-macroaggregate albumin ((99)Tc-MAA) scanning via subcutaneous arterial port was undertaken to measure lung/liver shunting ratio and tumor/liver ratio. Hepatic arterial infusion of (32)P-GMS was performed in 17 cases of HCC with a dose from 1.11 to 1.30 GBq. Twenty cases of HCC undergoing hepatic arterial chemoembolization (HACE) in the same period served as controls group. RESULTS: There was no treatment-related death in the 17 cases. In 7 of the 17 cases, AFP level and/or tumor size decreased by 50% after treatment, with a response rate of 64.7%. The median survival time was 5.5 months, and the 3-, 6-, 9-, 12-month survival rates were 94.1%, 44.1%, 31.0%, 24.4%, respectively. The therapeutic efficacy was better than that of HACE. The survival time was significantly longer in patients with T/N ratio >or= 2 than in those with T/N < 2 (P < 0.05). CONCLUSIONS: Hepatic arterial infusion of (32)P-GMS is an alternative treatment for unresected HCC.

Adult↗

PubMed1999

[Efficacy of TACE in treatment of intraportal tumor thrombi with double helical CT].

The present study observed alterations of the intraportal tumor thrombi before and after transcatheter hepatic arterial chemo-embolization(TACE) in 36 patients with massive hepatocellular carcinoma(HCC). Elscint double helical CT was used to scan liver in the portal phase before and after TACE. The results showed that the scan technique could be used to evaluate the distribution of intraportal tumor thrombi. After treating with TACE, retention of iodized oil was found in the intraportal tumor thrombi(14/36), and the intraportal tumor thrombi were reduced in 28 out of 36 cases. The survival rate was more than 1 year in 20 patients. These data indicate that the blood supply of the intraportal tumor thrombi comes from hepatic arterial system. TACE seems to be valuable for the treatment of intraportal tumor thrombi with massive HCC.

Adult↗

PubMed1999

[Effect of cadmium on the beta-adrenoreceptor of splenic cell of rats and its immunotoxicity].

Rats were given cadmium(Cd) alone or Cd with beta-antagonist in order to study the effect of Cd on beta-adrenoreceptor density of rat splenic cells. The subsets of T-lymphocytes (CD4+, CD8+, CD4+/CD8+) and the proliferation of T lymphocytes were also detected. Cadmium alone stimulated and increased beta-adrenoreceptor density of rat splenic cell membrane. The immunotoxicity of Cd showed that the proliferation of T-lymphocytes was inhibited and the subsets of T cells were changed. But in the animals with beta-antagonist, the immunotoxicity of Cd on T cells was decreased. It is concluded that beta-adrenoreceptor may play an important role in the mechanism of cadmium on cell immunotoxicity.

Animals↗

PubMed1999

[Survey of jugular bulb with MRA in sudden sensorineural hearing loss].

To evaluate the correlation between the size and position of the jugular bulb and the sudden sensorineural hearing loss(SSHL), the diameter and height of all jugular bulbs were measured with magnetic resonance angiography and analysed with statistics in 15 cases with SSHL and 35 cases without SSHL(as control). The ipsilateral and the contralateral bulbs of the SSHL were more asymmetrical than that of the control. The mean diameter and height of the ipsilateral bulbs of SSHL were larger than that of the dominant side bulbs of the control. It indicates that the heteroplasia of jugular bulbs which were greatly enlarged and bulgy upward might be related to SSHL.

Adult↗

PubMed1999

[Radiofrequency treatment of ethmoidal nerve with allergic rhinitis under nasal endoscopy].

OBJECTIVE: To study the effect of radiofrequency treatment of ethmoidal nerve on allergic rhinitis. METHOD: Eighty-eight cases of allergic rhinitis were treated with ethmoidal nerve radiofrequency under nasal endoscopy. RESULT: It showed marked effectiveness in 73 cases (83.0%), immprovement in 11 cases (12.5%) and failed in 4 cases (4.5%) in one year follow-up. The overall effective rate was 95.5%. CONCLUSION: This result indicated that it is a choice for treating allergic rhinitis to apply ethmoidal nerve radiofrequency under nasal endoscopy.

Adolescent↗

PubMed1999

[Separation and analysis of amino acids in secretion of psylla chinesis yang et li].

We used ion-exchange resin column chromatography to separate amino acids in secretion of Psylla Chinese Yang et Li and used capillary gas chromatography to analysis n-butyl-N-trifluoracetyl derivatives of the amino acids. Qualitative analysis was done by comparing with the standard amino acids and quantitative analysis by internal standard method. We determined thirteen amino acids in the secretion.

English Abstract↗

PubMed1999

[The use of AFLP technique for the study of genetic diversity in peanut bradyrhizobia].

A total of 146 bradyrhizobial strains including 133 peanut bradyrhizobia isolated from different regions and 13 reference strains representing B. japonicum and B. elkanii were studied for their genetic diversity by use of AFLP marker technique. The genomic similarity was analysed by numerical Taxonomy based on the AFLP patterns. The results showed that the genetic diversity of peanut bradyrhizbia were very high. Each strain had a identical AFLP pattern. AFLP technique is simple, fast, highly reproducible, and is a useful tool for evaluating genetic diversity.

Arachis↗

PubMed1999

[Purification and partial characterization of antagonistic proteins from Bacillus subtilis B034].

Bacillus subtilis B034, an antagonistic bacteria isolated from the phyllosphere of rice, strongly inhibits the growth of Xanthomonas oryzae pv. oryzae which causes the rice bacterial blight. Crude extract was obtained by precipitation of the cell-free culture of B034 with 70% saturated (NH4)2SO4. The suspension of the precipitate strongly inhibits Xanthomonas oryzae pv. o-ryzae, and it is thermostable, resistant to trypsin, partial sensitive to proteinase K, pronase E and chloroform. Its active pH range is wide, from 4.0 to more than 12.0, relative more stable in high pH. Two antagonistic peaks were obtained from the crude extract of B034 after Phenyl-Sepharose CL-4B, DEAE-Sephacel and FPLC Superdex 75 HR 10/30 column chromatography. One of these two peaks, named P2, was showed only single band with 50.3 kD and pI6.25 in SDS-PAGE and PAGE-IEF, respectively. The N-terminal partial sequence of protein P2 was analyzed.

Amino Acid Sequence↗

PubMed1999

[Excretion ratio of lactulose and mannitol as intestinal permeability index in healthy Chinese volunteers].

OBJECTIVE: To determine lactulose (L)/mannitol (M) excretion ratio with high pressure liquid chromatograph with pulsed electrochemical detection (HPLC-PED) in healthy Chinese volunteers. METHODS: Sixty healthy Chinese volunteers enrolled. For each volunteer the L/M permeability study was performed twice by two different doses, as small dose (1 g mannitol and 2 g lactulose) and regular dose (5 g mannitol and 10 g lactulose). The urine were collected during 6 hours after ingestion of the test solution. The M and L concentrations were analyzed by HPLC with pulsed electrochemical detection. RESULTS: The L/M ratio was 0.026 +/- 0.006 in the small doses tests, and 0.036 +/- 0.008 in the large doses tests. CONCLUSIONS: With HPLC-PED detection, a low doses of lactulose and mannitol can be used to study intestinal permeability. Determination of the L/M ratio may be a way of evaluating intestinal barrier function in clinical practice.

Adult↗

PubMed1999

[Artificial neural network application in spectral recognition].

An artificial neural network was devised and established for spectral matching. It was proved that when training sample spectra and unknown spectra had the same magnitude calibration, the network recognized spectra very well and had some advantages over other conventional spectral matching methods.

Computer Simulation↗

PubMed1999

[Simultaneous determination of phosphorus in hair by ICP-AES].

A useful ICP-AES method for the determination of microelements P, Zn, Cu, Fe, Ca, Mg, Pb, Mn and Al in hair is described. The JY38 spectrometer in the JY70PII ICP-AES system,equipped with a 3600 g/mm holographic diffraction grating (1 m focal length) was used for the determination of phosphorus. The detection limit value (at 3 standard deviations of background) for spectral line 213.618 nm is 0.022 microg x mL(-1).

Hair↗

PubMed1998

Kinetics of Particle Transport to a Solid Surface from an Impinging Jet under Surface and External Force Fields.

Based on the presented model for the impinging jet system, extensive theoretical analysis was made on particle deposition. Complete transport equations with consideration of gravity, van der Waals, and electrical double layer (EDL) interactions, as well as hydrodynamic interactions, were numerically solved. The influences of gravity, van der Waals, and electrical double layer interactions on the particle deposition rates (in terms of the Sherwood number) were presented. The results demonstrate that the asymmetric EDL interaction, which has been ignored in previous treatments, has an impact on the particle deposition rate. It was also found that the Sherwood number is strongly dependent on the characteristics of the particle-collector interaction energy profiles, such as the height of the energy barrier and the depth of the secondary energy minimum. Particularly, the effects of the height of the energy barrier and the depth of the secondary energy minimum on the Sherwood number for different Peclet numbers were discussed. In addition, a simple expression was derived for quantitatively estimating the contributions to the deposition rate due to particle diffusion, migration, and convection. With the aid of calculated particle concentration distributions, this expression can be used to understand the numerical predictions. Copyright 1998 Academic Press.

Journal Article↗

PubMed1998

[Study on the changes of the levels of SOD and MDA in lung and MN in bone marrow exposed to cooking fume in rats].

In order to investigate the mechanism of the activities of superoxide dismutase (SOD) and the concentration of malondialdehyde (MDA) in lung and rate of micro-nucleus (MN) in bone marrow by which rape oil fume condensate(RC) exert their effect in rat lung, pouring into traches SD rat was performed with RC. Results showed that the SOD activities in RC and B(a)P groups were significantly higher than those in DMSO and control groups(P < 0.05). The concentrations of MDA were significantly lower than that in DMSO and control groups (P < 0.05). In experimental groups SOD/MDA decreased. MN rate significantly increased. It is concluded that lung tissue may be a target of RC.

Air Pollutants↗

PubMed1998

Pathogenic implications of mutations in the tau gene in pallido-ponto-nigral degeneration and related neurodegenerative disorders linked to chromosome 17.

Pallido-ponto-nigral degeneration (PPND) is one of the most well characterized familial neurodegenerative disorders linked to chromosome 17q21-22. These hereditary disorders are known collectively as frontotemporal dementia (FTD) and parkinsonism linked to chromosome 17 (FTDP-17). Although the clinical features and associated regional variations in the neuronal loss observed in different FTDP-17 kindreds are diverse, the diagnostic lesions of FTDP-17 brains are tau-rich filaments in the cytoplasm of specific subpopulations of neurons and glial cells. The microtubule associated protein (tau) gene is located on chromosome 17q21-22. For these reasons, we investigated the possibility that PPND and other FTDP-17 syndromes might be caused by mutations in the tau gene. Two missense mutations in exon 10 of the tau gene that segregate with disease, Asn279(Lys) in the PPND kindred and Pro301(Leu) in four other FTDP-17 kindreds, were found. A third mutation was found in the intron adjacent to the 3' splice site of exon 10 in patients from another FTDP-17 family. Transcripts that contain exon 10 encode tau isoforms with four microtubule (MT)-binding repeats (4Rtau) as opposed to tau isoforms with three MT-binding repeats (3Rtau). The insoluble tau aggregates isolated from brains of patients with each mutation were analyzed by immunoblotting using tau-specific antibodies. For each of three mutations, abnormal tau with an apparent Mr of 64 and 69 was observed. The dephosphorylated material comigrated with tau isoforms containing exon 10 having four MT-binding repeats but not with 3Rtau. Thus, the brains of patients with both the missense mutations and the splice junction mutation contain aggregates of insoluble 4Rtau in filamentous inclusions, which may lead to neurodegeneration.

Adult↗

PubMed1998

The zeta-Potential of Silicone Oil Droplets Dispersed in Aqueous Solutions.

An experimental method to measure the zeta-potential of small liquid droplets dispersed in another immiscible liquid was presented in this paper. Basically, a liquid droplet was held stationary in a test cell by applying a proper static electric field. An existing theory shows that the electrical force experienced by the droplet can be related to the zeta-potential of the liquid droplet. Thus the zeta-potential can be determined from the force balance among the electrical force, the gravitational force, and the buoyancy force being exerted on the stationary droplet. This electrical suspension method was applied to study the effects of pH values, ionic features, and concentrations of three electrolytes and two ionic surfactants on the zeta-potential of the silicone oil (No. 1) droplets. Copyright 1998 Academic Press.

Journal Article↗

PubMed1998

Measurements of Contact Angles between an Oil-Water Interface and a Fiber by the ACDPAC Technique.

The ACRPAC (Analysis of Capillary Rise Profile Around a Cylinder) method was modified and extended to measure the contact angles between an oil-water interface and a fiber. Basically, the accurate image of the partial capillary depression profile was acquired and digitized by applying computer digital image processing and analysis techniques. The contact angle was determined by finding the best fit of the theoretically predicted profile, i.e., the curve representing a solution of the Laplace equation of capillarity, to the physically observed liquid-liquid interface. This analysis of the capillary depression profile around a cylinder (ACDPAC) technique was used to measure the contact angles of different water-oil interfaces on cylindrical glass fibers pre-coated with FC725. The wettability of the fiber-water-oil systems with varying oil and aqueous phases was examined. In particular, the wetting effects of a cationic surfactant cetyltrimethylammonium bromide (CTAB) and an anionic surfactant sodium dodecyl sulfate (SDS) dissolved in the aqueous phase were studied by using the ACDPAC technique. The oil phases tested were two dimethyl siloxane liquids, silicone oil A-type and silicone oil B-type. Copyright 1998 Academic Press.

Journal Article↗

PubMed1998

Source of electrocardiographic ST changes in subendocardial ischemia.

To clarify the source of electrocardiographic ST depression associated with ischemia, a sheep model of subendocardial ischemia was developed in which simultaneous epicardial and endocardial ST potentials were mapped, and a computer model using the bidomain technique was developed to explain the results. To produce ischemia in different territories of the myocardium in the same animal, the left anterior descending coronary artery and left circumflex coronary artery were partially constricted in sequence. Results from 36 sheep and the computer simulation are reported. The distributions of epicardial potentials from either ischemic source were very similar (r=0.77+/-0.14, P<0.0001), with both showing ST depression on the free wall of the left ventricle and no association between the ST depression and the ischemic region. However, endocardial potentials showed that ST elevation was directly associated with the region of reduced blood flow. Insulating the heart from the surrounding tissue with plastic increased the magnitude of epicardial ST potentials, which was consistent with an intramyocardial source. Increasing the percent stenosis of a coronary artery increased epicardial ST depression at the lateral boundary and resulted in ST elevation starting from the ischemic center as ischemia became transmural. Computer simulation using the bidomain model reproduced the epicardial ST patterns and suggested that the ST depression was generated at the lateral boundary between ischemic and normal territories. ST depression on the epicardium reflected the position of this lateral boundary. The boundaries of ischemic territories are shared, and only those appearing on the free wall contribute to external ST potential fields. These effects explain why body surface ST depression does not localize cardiac ischemia in humans.

Animals↗