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Biomedical subjects

B L Liu

Publications and source records attributed to B L Liu.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Prospective study on the treatment of facial palsy with dynamic free muscle transplantation].

In this prospective study, patients were randomly divided into 3 groups according to 3 different operation procedures used to correct facial palsy with microneurovascular anastomosed muscle transplantation: In group 1, 9 patients accepted cross face transplantation of segmental latissimus dorsi muscle flap with super-long neurovascular pedicle, through upper labial tunnel, anastomosed in normal face (one stage method); In group 2, 7 patients accepted cross face nerve graft and secondary free muscle transplantation by neurovascular anastomoses in paralyzed face (two stage method); In group 3, 5 patients, free muscle transplantation by microneurovascular anastomosis in paralyzed face. The appreciation for the results was carried out in 16 patients who had been followed-up more than 1 year. In terms of functional recovery, the success rate ranged in excellent and good reached 93.8%. There were not significant differences among groups. The patients of less than 40-year-old got better results and the correlation between operative effects and both cause and course of disease could not be found. It was considered that the nerve regeneration speed and quality in one stage method were better than sural nerve graft with small saphenous vein anastomosis, because physiological blood supply was kept well along the nerve pedicle and regenerating nerve fibers need not pass through two suture sites. Patients satisfied the results after the swelling was gone because one stage method had the advantages of face lift and selective neurotomy at the same time. The course of treatment was shortened significantly as well.

Adolescent↗
PubMed1993

[The study of oxidative injury of alveolar macrophage in the development of silicosis].

The changes of oxidant and anti-oxidant system of alveolar macrophage under the influence of quartz were studied from different angles such as in vitro cell test, experimental rat silicosis and patients with silicosis. The results showed that quartz dust could induce the production of oxygen derived free radicals of alveolar macrophages which could lead to lipid peroxidation of cell membrane system. These changes were especially obvious in the early stage of experimental rat silicosis and in the patients with silicosis. The process recycling dust involving ingestion, destruction and re--releasing of the dust by the alveolar macrophages, was an important link in the production and development of lung fibrosis. It also illustrated the role played by oxidative injury of alveolar macrophages in the development of lung fibrosis.

Adult↗
PubMed1991

Influence of the H-subunit and Fe2+ on electron transport from I- to QA in Fe(2+)-free and/or H-free reaction centers from Rhodobacter sphaeroides R-26.

From reaction centres (RC) of Rhodobacter sphaeroides R-26 two LM preparations with 0.90 Fe2+/RC (LM) and 0.10 Fe2+/RC (LM/dFe) were prepared. Reconstitution of LM/dFe with the H-subunit and subsequently with Zn2+ yielded LMH/dFe and LMH/dFe and LMH/dFe + Zn preparations, respectively. In these four samples the decay of the primary radical pair P+I- was studied by means of transient absorption spectroscopy and compared with that in native RC. In LMH/dFe the reduction of QA by Bpheo a occurred in 5 ns, with concomitant increase in the yield of PT, the triplet state of the primary donor. In the LM/dFe, LM and LMH/dFe + Zn preparations the decay of I- had the same rate (200 ps)-1 as in native RC. Thus, neither the H-subunit in the RC nor a divalent metal as Fe2+ or Zn2+ are necessary per se for fast reduction of QA. Only demetallation in the presence of the H-subunit slows down the reduction of QA.

Cations, Divalent↗
PubMed1991

Small-vessel pathology and anastomosis following maxillofacial firearm wounds: an experimental study.

This experiment was designed to provide a biological basis for early reconstruction of maxillofacial defects caused by firearms using free vascularized flap transfer. The pathologic changes of small-vessel injury, injury mechanism, and the feasibility for early anastomosis of these vessels in the maxillofacial region following high-velocity missile wounds were studied. Dogs' faces were wounded by a steel sphere, weighing 0.7 g and 1.03 g, with an initial velocity of 1,300 m/s or 1,500 m/s. Angiography and high-speed x-ray photography were used to record the effect of injury to blood vessels and other tissues. The pathologic changes in the small blood vessels in the wounds were studied by light microscopy (LM) and electron microscopy (EM). Anastomosis of small vessels in the wound was performed at different times after injury. There were temporary cavity effects and small vascular injury in the wounds. The pathologic changes of the small vessels included microthrombus formation, endothelial loss, breaks in the internal elastic layer, and necrosis. Degeneration of cells was found to end 3 cm from the wound edge. Anastomosis of the vessels performed 3 days after injury provided good short-term patency. These results suggest that the operation for repairing facial defects should be performed 3 days after injury.

Animals↗
PubMed1990

Antibodies directed against the thiomannose moiety of a glycoconjugate of 2-imino-2-methoxyethyl 1-thio-alpha-D-mannopyranoside and bovine serum albumin.

Anti-thiomannose antibodies were induced in rabbits immunized with a glycoconjugate of 2-imino-2-methoxyethyl 1-thio-alpha-D-mannopyranoside (Man-S) and bovine serum albumin (BSA). Also anti-BSA antibodies directed against the BSA moiety of the glycoconjugate were detected in low concentrations in the immune serum. However, antibodies against the combinatorial epitope of the hapten group and the carrier protein were not detected. The anti-thiomannose and the anti-BSA antibodies were isolated in pure forms by affinity chromatography on Sepharose 4B-bearing thiomannosyl-BSA ligands or BSA ligands. The anti-thiomannose antibodies constituted the major fraction of the antibodies, and these antibodies were isolated in pure form for the first time. The specificity of the thiomannose antibodies was established from data of experiments of periodate oxidation, perpropionic acid oxidation, hapten inhibition, and agar diffusion, Isoelectrofocusing showed that the anti-thiomannose antibody preparation consisted of at least six isomeric proteins, all of which exhibited antibody activity against the glycoconjugate of thiomannose and BSA.

Animals↗
PubMed1990

Quantitative study of the structure-stability relationship of Tc complexes.

By studying structural parameters (van der Waals radius and bond length from x-ray crystallography) of more than 100 known Tc compounds and using the cone packing model, a stability indicator of the Tc compounds was derived. The indicator is based on the solid angle factor sum (SAS), which is calculated from van der Waals radii and bond lengths between all coordinating atoms and Tc. The average SAS value is 0.97 +/- 0.13. The SAS value reflects the limits of the packing of ligand around Tc. The quantitative calculation of the SAS is useful for predicting stability and designing new Tc radiopharmaceuticals.

Drug Stability↗
PubMed1990

Quantitative study of the structure-stability relationship of TcvO(III) complexes.

This paper describes the quantitative structure-stability relationship of TcvON2S2 compounds using a stability indicator based on the solid angle factor sum (SAS) for predicting the in vitro stability. The SAS values of six TcvON2S2 and one TcvON4 (D,L-HMPAO) complexes were calculated from their x-ray crystallography data. The rank order of in vitro stability of these compounds, as measured by ligand exchange reaction, is directly related to that of the SAS values. The SAS values are potentially useful for predicting stability and designing new 99mTc radiopharmaceuticals.

Drug Stability↗
PubMed1990

Comparison of the properties of glucoamylases from Rhizopus niveus and Aspergillus niger.

Some properties of the glucoamylase from Rhizopus niveus have been determined and compared with the comparable properties of the glucoamylase from Aspergillus niger. The enzymes from these organisms possess the following common properties: quantitative conversion of starch to glucose, molecular weights in the range 95,500 to 97,500, and glycoprotein structures with many oligosaccharide side chains attached to the protein moieties of the enzymes. Differences in the glucoamylases exist in electrophoretic mobility, amino acid composition, nature of carbohydrate units, and types of glycosidic linkages. Lysine, threonine, serine, glutamic acid, tyrosine, and phenylalanine differ in the two glucoamylases by 25 to 50%. Whereas the enzyme from R. niveus contains mannose and glucosamine, in the N-acetyl form, as the carbohydrate constituents, the enzyme from A. niger contains mannose, glucose, and galactose. The carbohydrate chains of the R. niveus enzyme are linked by O-glycosidic and N-glycosidic linkages to the protein, while those of the A. niger enzyme are linked by O-glycosidic linkages only. Antibodies directed against the two glucosamylases have been isolated by affinity chromatography and found to be specific for the carbohydrate units of the glucoamylases. Cross reactions did not occur between the glucoamylases and the purified antibodies.

Amino Acids↗
PubMed1990

A new myocardial imaging agent: synthesis, characterization, and biodistribution of gallium-68-BAT-TECH.

In order to develop a new myocardial perfusion agent for positron emission tomography (PET), a new lipid-soluble gallium complex was evaluated. Synthesis, radiolabeling, characterization, and biodistribution of a unique gallium complex, [67Ga]BAT-TECH (bis-aminoethanethiol-tetraethyl-cyclohexyl), are described. The complex formation between Ga+3 and BAT-TECH ligand is simple, rapid, and of high yield (greater than or equal to 95%). This process is amenable to kit formulation. The complex has a net charge of +1 and a Ga/ligand ratio of 1:1. Biodistribution in rats shows high uptake in the heart as well as in the liver. When [68Ga] BAT-TECH was injected into a monkey, the heart and liver are clearly delineated by PET imaging, suggesting that this complex may be a possible tracer for myocardial perfusion imaging.

Animals↗
PubMed1989

[Study on molecular hybridization with biotin-labelled HPV 16 DNA probe in human cervical carcinoma].

Biotin-labelled human papillomavirus (HPV) 16 type DNA probe was prepared by the techniques of molecular biology. And dot hybridization technique was used to detect the HPV 16 homologous sequences in the tissues DNA of human cervical carcinoma. The results indicated that 16 cases out of 28 of the human cervical carcinoma tissues were positive. The positive rate was 57%. The other 4 cases of normal uterine cervix tissues were negative. Only 1 in 4 chronic cervicitis tissues showed positive. The HPV 16 plasmid DNA, as the positive control group, showed strong positive, while lambda-phage DNA was negative. The results have shown that the genome of the HPV actually exists in the tissue of the cervical carcinoma and that there is a close relationship between the cervical carcinoma and HPV infection. This experiment adopted the Biotin-labelled HPV 16 DNA probe. And it may provide us with a quick and sensitive method for investigation of the infection of HPV and its role in the carcinogenesis of cervical carcinoma.

Biotin↗
PubMed1989

Synthesis, characterization, and biodistribution of [113mIn]TE-BAT: a new myocardial imaging agent.

In order to develop a new myocardial perfusion agent, new lipid-soluble complexes containing a net charge of +1 were evaluated. Synthesis, radiolabeling, characterization, and biodistribution of a unique indium complex, [113mIn]TE-BAT (tetraethyl-bis-aminoethanethiol), are described. The complex formation between In +3 and TE-BAT ligand is rapid, simple, and of high yield (greater than or equal to 95%). This process is amenable to kit formulation. The complex has a net charge of +1 and an In/ligand ratio of 1:1. Biodistribution in mice shows higher heart uptake and longer retention as compared to 201TI. This complex, when labeled with 111In, shows promise as a possible tracer for myocardial perfusion imaging.

Animals↗
PubMed1987

Clinical evaluation of the 99mTc-labeled myocardial imaging agent, hexakis (t-butylisonitrile)-technetium.

99mTc-TBI myocardial perfusion imaging has been studied in 7 normal subjects and 24 patients with coronary artery disease. Scintigraphic data revealed that 99mTc-TBI myocardial perfusion imaging is more sensitive than ECG in detecting myocardial infarction. In comparing 99mTc-TBI imaging with contrast angiography, its' sensitivity for the diagnosis of coronary artery disease was 91.7%.

Adult↗
PubMed1987

Comparison of [82Br]4-bromoantipyrine and [125I]4-iodoantipyrine: the kinetics of exchange reaction and biodistribution in rats.

Kinetics and mechanism of isotope exchange reaction between [82Br]bromide anion and 4-bromoantipyrine (BrAP), and the iodine-bromine exchange reaction between [125I]iodide anion and BrAP were studied. The preparation of [82Br]BrAP followed by exponential exchange law, the kinetics of the exchange reaction is a second-order reaction with an activation energy of 23.3 kcal/mol. The optimal exchange condition for halogen exchange between [125I]iodide and BrAP was by a hydrothermal melt method at 110 degrees C and 5 min reaction time. The partition coefficient at pH 7.0 for IAP and BrAP was 20.9 and 13.5, respectively. However, BrAP, which displayed the lower partition coefficient, showed higher brain uptake in rats than that for IAP (2.0% dose/organ vs 1.74% dose/organ), at 2 min after an i.v. injection.

Animals↗