Biomedical subjects
Publications and source records attributed to W Huang.
By means of observing at regular intervals and on tixed plants, the growth stages, organogenetic habits, content of nutrient elements and its changing regularity, storage habit of dry matter, relationship between aerial and subterraneous parts, and fertilizer requirements have been studied for Ophiopogen japonicus.
Field investigation and laboratory analysis were made on the formation conditions, as well as physical and chemical properties of soils for growth of Ophiopogon japonicus.
Since Wang Bing made great contributions to the development of TCM, exploration on Wang Bing's life story is helpful to the analysis on the intention of his medical works. There are controversies on Wang's life story, some of which are still in debate. Through the elucidation of Wang's name, other names, sobriquet, dates of birth and death, official positons and scholarly lineage, this author holds that more relevant historical materials are needed so that the puzzle of his life story can be eventually revealed and uncovered.
OBJECTIVE: To search for immunomodulators to improve postburn immune function disorder. METHOD: We studied the Chinese medicinal herbs. On the basis of previous data, we prepared a kind of Chinese medicinal herbal mixture and studied its effects in vivo and in vitro. RESULT: The mixture could restore the cell-mediated immune response such as the production of interleukin 2 and the T cell proliferative ability, and could also adjust the levels of serum acute-phase reaction proteins, i.e, haptoglobin, prealbumin, transferrin and alpha 1-acid glycoprotein. CONCLUSION: The Chinese herbal mixture showed immune regulatory effects on body defence imbalance and also on acute phase reaction proteins in burn patients.
In an attempt to search for novel cardiovascular drugs which might act on calcium or potassium channels, on the basis of the previous study of our group, 15 1-(4-alkyloxy)benzyl-1,2,3,4-tetrahydroisoquinolines derivatives were designed and synthesized among which 10 were not reported previously in the literature. Preliminary pharmacological studies showed that most of these compounds exhibited relaxation of rat thoria aorta in vitro. Compound III9 exhibited potent inhibiting action on low KCl(20 mmol.L-1)-induced contraction of rat aorta, and significant protective effect on experimental arrhythmia in rats.
For searching more effective antiarrhythmic agents, on the basis of integration of the structural feature of certain potassium channel blockers available, various acylamino groups were introduced to the position 4 of the benzyl ring of this series of compounds. Thus, eight 1-(4-acylamino)benzyl-1,2,3,4-tetrahydroisoquinolines were designed and synthesized, which had not been reported in the literatures. Compounds V1, V2 and V6 at concentration 10(-6) mol.L-1 depressed rat aortia contraction induced by high KCl (80 mmol.L-1). The effect was similar to that of tetrandrine. Compound V6 showed potent antiarrhythmic activity at the dosage of 1 mg.kg-1.
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Human cytomegalovirus(HCMV) is one of the important pathogens to human being. At present there is no specific antiviral drugs. In order to find an effective antisense phosphorothioate deoxyoligonucleotide(ASON) against--HCMV, the antiviral activity was observed in this study. Three ASON complementary to UL36 gene were synthesized according to immediate early gene sequence of HCMV, and the antiviral activity was evaluated in vitro using human embryonic lung cells as targeted cells of virus infections. The result showed that ASON targeting to splice donor had fairly strong antiviral activity. The specific ASON has sure antiviral activity. As a new means, it may be used to prevent and treat human CMV infections.
This paper reports the fermentation techmology of bacterial feed No.633. A new fermentational technic, which was composed of fermentation medium, optimum pH, temperature, airate flow, pot pressure and fermentation time, was established.
PURPOSE: To study the factors that influence ultrasound biomicroscopy(UBM) examination on anterior chamber angle, and explore a dynamic differentiating method. METHOD: To compare the UBM morphologic characters of the anterior chamber angle of the high-risk chamber angle and adhered angle groups under different illumination. RESULT: Under routine working condition, some eyes of the high-risk-group (9/12) displayed bombing iris with extremely narrowly-opened angle; but 3/12 cases and the control group showed bombing iris and closed angle. Under bright circumstances, all angles of the high-risk group showed widely-opened, but the control group remained closed. CONCLUSION: Different illumination influences the UBM examination of the anterior chamber angle significantly, we should differentiate the angle morphologic characters under different illumination if it seems to be closed. Factors that affect the UBM examination were also discussed.
PURPOSE: We cultured human ciliary muscle [HCM] cells to study their growth, ultrastructure, immunohistochemistry and functional characters. METHODS: HCM cells from 10 young donor eyes were cultured with collagenase IV digestion procedures in vitro, the cells were identified by eletronmicroscope and immunohistochemistry assay, their function were studied by single-cell-contraction assay. RESULTS: The cells were passed and grew in Hill-Valley pattern after conflunet; abundant filaments were presented under electronmicroscope. In Desmin protein immunohistochemistry study, the cultured cells were stained positive; in tissue sections, HCM cells stained positive, vascular smooth muscle stained positive weakly, but fibroblast cells and endothelial cells stained negative. 10(-3) M Carbachol could induce the cultured cells contract, this effect was antagonized by 10(-3) M Atropine. CONCLUSION: We successfully cultured HCM cells, which were able to contract.
In some cases, the use of conventional GC/FTIR technique is limited due to its lower detectability to micro-components in organic mixtues in comparison to GC/MS. In this paper, an integration of LG/GC using retention gap technique with partially concurrent solvent evaporation, as a efficient chromatographic system for sample preconcentration and preseparation, was coupled into FTIR system in order to overcome the detectability problems of GC/FTIR analysis. The applicability of the on-line LG-GC/FTIR method is demonstrated by analysis of the isomers of divinylbenzene in purified diethyl malonate under conditions of hexane/dichloromethane (85:15) used as mobile phase in LC, solvent evaporation temperature of 75 degrees C and inlet pressure of 0.20MPa etc.
The angiotensin I-converting enzyme (kininase II, ACE) is the major angiotensin II forming and kinin degrading enzyme in the circulation, and has other physiological peptide substrates. Recent studies have established that the interindividual variability in the levels of ACE in plasma and tissues is under the influence of a genetic polymorphism. The genetic polymorphism of ACE levels has been linked in case-control studies to the susceptibility of developing cardiovascular diseases, especially myocardial infarction and diabetic nephropathy, and to the risk of progression of renal diseases. The new concept that the level of ACE in peripheral circulations and tissue interstitium is an important factor in the determinism of the local concentration of peptides and their putative protective/deleterious effects, especially in the kidney and the heart, will be further appraised.
Linear peptides derived from the membrane proximal region of the gp41 ectodomain are effective inhibitors of HIV type 1 (HIV-1)-mediated fusion events. These inhibitory peptides lack structure in solution, rendering mechanistic interpretation of their activity difficult. Using structurally constrained analogs of these molecules, we demonstrate that the peptides inhibit infectivity by adopting a helical conformation. Moreover, we show that a specific face of the helix must be exposed to block viral infectivity. Recent crystal structures show that the region of gp41 corresponding to the inhibitory peptides is helical and uses the analogous face to pack against a groove formed by an N-terminal coiled-coil trimer. Our results provide a direct link between the inhibition of HIV-1 infectivity by these peptides and the x-ray structures, and suggest that the conformation of gp41 observed by crystallography represents the fusogenic state. Other agents that block HIV-1 infectivity by binding to this groove may hold promise for the treatment of AIDS.
The structural similarity of lysosphingolipids to lysophosphatidic acid (LPA) prompted a sequence-based search for lysosphingolipid receptors using cDNA sequence of the Edg2 human LPA receptor. Two closely related G protein-coupled receptors, rat H218 and human Edg3, are highly similar to Edg2. When overexpressed in Jurkat cells, H218 and Edg3 activated serum response element-driven transcriptional reporter gene in response to sphingosine 1-phosphate (S1P), dihydro-S1P and sphingosylphosphorylcholine, but not to LPA. H218 and Edg3 expressed in Xenopus oocytes conferred responsiveness to S1P and dihydro-S1P in agonist-triggered 45Ca2+ efflux. Therefore, H218 and Edg3 are functional receptors for S1P and perhaps other closely related lysosphingolipids.
Whereas cells normally resist attack by PLA2, they become susceptible under certain pathological conditions. To ascertain the regulatory mechanisms that induce cellular susceptibility to PLA2, the effect of thionin on S49 cells was examined in the presence of PLA2. Thionin alone was unable to evoke hydrolysis of the lipid bilayer. Likewise, the addition of PLA2 alone caused production of only a minimal amount of free fatty acid. However, thionin and PLA2 together resulted in significant hydrolysis of the cell membrane. Thionin caused perturbation of the bilayer structure as suggested by the changes in the emission spectra of laurdan and the permeability of the membrane to propidium iodide. These changes correlated quantitatively with the susceptibility of the lipid bilayer to PLA2. Furthermore, thionin induced a modest increase in intracellular Ca2+. The source of this Ca2+ was the extracellular fluid since EDTA in the extracellular medium inhibited the Ca2+ influx. Moreover, cobalt chloride, a universal Ca2+ channel blocker, prevented the rise in intracellular Ca2+, the uptake of propidium iodide, and the susceptibility to PLA2 induced by thionin. In contrast, the changes in the laurdan emission caused by the thionin were not affected by the cobalt. Furthermore, incubation of the cells with the calcium ionophore A23187 also caused the cells to become susceptible to PLA2. We hypothesize that thionin causes S49 cell membranes to become susceptible to PLA2 by a Ca2+-dependent perturbation of the bilayer structure.
Understanding the properties of immobilized proteins is critical to the optimal design of biosensors, bioseparations, and bioreactors. The protease subtilisin BPN' was used as a model protein to study how the orientation of immobilized enzyme molecules on surfaces affects their catalytic properties. To achieve this goal, a single cysteine residue was introduced into the cysteine-free enzyme by site-directed mutagenesis. This cysteine residue was designed to be away from the active site of the enzyme. The enzyme molecules were immobilized through the side-chain sulfhydryl group of the cysteine residue on several supports. This site-specific immobilization method leads to ordered two-dimensional arrays of enzyme molecules on the support surface with the active sites of the enzyme oriented toward the solution phase. Such oriented immobilized subtilisin demonstrated a higher catalytic efficiency compared to subtilisin that was immobilized by a conventional method that leads to random immobilization.
beta-lactamase is a bacterial enzyme that catalyzes the hydrolysis of beta-lactam antibiotics such as penicillins and cephalosporins. TEM-1 beta-lactamase is a prevalent beta-lactamase found in Gram-negative bacteria and is capable of hydrolyzing both penicillins and cephalosporins, except for the extended-spectrum cephalosporins. To identify the sequence determinants in the active site for a given antibiotic substrate, random libraries were constructed that each contain all possible amino acid combinations for the designated region of TEM-1 beta-lactamase. To establish the determinants of substrate specificity for cephalosporins versus those for penicillins, these active site libraries have been screened for mutants with high levels of activity for the second generation cephalosporin cephaloridine. Based on the sequence results, substitutions of W165S, A237T, and E240C were identified as cephalosporin-specific. Kinetic analysis of these mutants was done to determine whether each is capable of distinguishing between the two classes of antibiotics. Both the A237T and E240C substitutions, alone or in combination, exhibited increased cephalosporinase activity and decreased penicillinase activity relative to the wild-type enzyme. A sequence comparison between functional mutants selected for cephaloridine hydrolytic activity and functional mutants previously selected for ampicillin hydrolytic activity suggests that TEM-1 beta-lactamase has greater restrictions in maintaining cephalosporinase activity versus maintaining penicillinase activity.