Endangered right whales on the southeastern Bering Sea shelf.
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Animal Migration↗
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Results for “Chain Migration”
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Ocean science. Creatures great and small are stirring the ocean.
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Animal Migration↗
Hypercalcaemia due to calcium binding by a polymeric IgA kappa-paraprotein.
Total serum calcium concentration was raised in a 63-year-old lady with multiple myeloma and markedly elevated serum IgA kappa-paraprotein concentration. Symptoms of hypercalcaemia were absent, and serum ionized calcium was normal, suggesting calcium binding by the abnormal protein. This was demonstrated directly after isolation of the paraprotein and characterization of the calcium/protein interaction. After reduction of the paraprotein with mercaptoethanol, sodium dodecyl sulphate polyacrylamide gradient gel electrophoresis revealed two bands corresponding to light and heavy chains, but under non-reducing conditions the isolated paraprotein migrated in a series of bands, possibly representing polymeric forms of the basic immunoglobulin moiety.
Aged↗
[Analysis of chiral compounds by micelle electrokinetic capillary chromatography].
An overview on applications of micelle electrokinetic capillary chromatography (MECC) in chiral compounds analysis is presented. Ionic chiral surfactants such as bile salts, long-alkyl-chain surfactants and high-molecular-weight surfactants, which can migrate with electroosmosis and its electrophoretic mobility, and interact with the solutes, are employed as chiral selectors. Addition of electrically neutral chiral selectors such as cyclodextrins is also successful in MECC separation. Theory of MECC enantiomer separation is briefly described.
Bile Acids and Salts↗
[An analysis of the molecular forms of the lipopolysaccharide from Pseudomonas syringae pv. atrofaciens IMV K-1025].
Water extract and salt-EDTA extract of Pseudomonas syringae, pv. atrofaciens cells were fractionated by ultracentrifugation with following salting out of ultracentrifugal supernatant by ammonium sulphate at 55% saturation (pH 4.5). The composition and distribution of LPS molecular forms were studied in the obtained fractions by means of electrophoresis in 10% polyacrylamide gel with 1% sodium dodecylsulphate when staining gels by silver nitrate and cumassi. It is shown that ultracentrifugal supernatant and a sediment as well as sulphate sediment contain S-LPS and R-LPS. SR-LPS is not differentiated. Sulphate supernatant does not contain the determinable amount of S-LPS but it is enriched by the proteins with molecular weights of 65-15 kDalton. S-LPS is localized in the gel area which corresponds to mobilities of polypeptides with molecular weights 130-45 KDalton and the number of monomeric links in O-specific chains of its molecules reaches 25-30. R-LPS migrates under electrophoresis in gel to the mobility zone of polypeptides with molecular weights 14.5-16 kDalton.
Bacterial Outer Membrane Proteins↗
[Ecological and hygienic concepts of human nutrition].
The paper presents data on the development of eco-hygienic concept of human nutrition. The scheme of migration of various xenobiotics and biological contaminants along the food chain is given. The necessity for the substantiation of unified MACs of alien substances for all eco-systems is indicated. The ++eco-hygienic concept of nutrition should be directed at the protection (purity) of the inner human environment and normalization of the processes of its activity in interrelations with the environment.
Environmental Monitoring↗
Synthesis of complement factor B by the human monocyte U-937 cell line. Augmentation by immunostimulatory agents.
The human pre-monocytic cell line U-937 was shown to synthesize and to secrete increasing amounts of factor B in short term cultures in serum-free medium containing BSA. The kinetics of factor B production were higher on day 2 than on days 1 and 3. The production of factor B was reversibly inhibited by cycloheximide, indicating de novo synthesis. Metabolic labeling with [35S]-methionine and SDS-PAGE analysis revealed that both intracellular and secreted factor B were single-chain proteins with similar m.w. (90,000), which co-migrated with purified plasma factor B. Incubation of U-937 cells with the immunostimulants PMA, LPS, IFN-gamma, and IL-1 resulted in a dose-dependent augmentation of factor B production. A 24-h exposure to IL-1 was shown to be required for maximal stimulation. A combination of suboptimal doses of LPS and IFN-gamma was shown to exert a synergistic effect on factor B production. The U-937 cell line is thus a valuable model for the study of the regulation of the factor B gene expression.
Adjuvants, Immunologic↗
Isolation of microtubules and a dynein-like MgATPase from unfertilized sea urchin eggs.
Taxol was used to prepare microtubules from unfertilized eggs of sea urchins Lytechinus pictus, Strongylocentrotus droebachiensis , and Strongylocentrotus purpuratus. By electron microscopy, these microtubules possessed normal morphology and were decorated with projections. The polypeptides present were tubulin plus microtubule-associated proteins (MAPs) which included various high molecular weight polypeptides, and a Mr = 80,000 polypeptide. These MAPs were extracted from the microtubules by differential centrifugation in high ionic strength buffers, yielding a pellet of microtubules which were not decorated with projections. The Mr = 80,000 and high molecular weight MAPs were separated using Bio-Gel A-1.5 m chromatography, and shown to bind taxol-stabilized microtubules assembled from purified bovine brain tubulin. A dynein-like MgATPase activity is present in sea urchin egg extracts. 10-20% of this MgATPase co-pelleted with the taxol-assembled microtubules, under conditions where greater than 90% of the tubulin pelleted. During subsequent fractionation of the microtubules, by (i) high salt extraction followed by gel filtration or sucrose density gradient fractionation or (ii) ATP extraction, the MgATpase co-purified with high Mr MAPs. The MgATPase which remained in the microtubule-depleted egg extract was partially purified by (NH4)2SO4 fractionation, followed by Bio-Gel A-5 m and hydroxylapatite chromatography. The high Mr MAP MgATPase and the hydroxylapatite MgATPase both contained a prominent polypeptide (Mr approximately 350,000), which co-migrated on sodium dodecyl sulfate gels with the major heavy chain of dynein extracted from sperm axonemes. Our data suggest that this Mr approximately 350,000 polypeptide is cytoplasmic dynein.
Adenosine Triphosphatases↗
Role of the regulatory light chains in skeletal muscle actomyosin ATPase and in minifilament formation.
Incubation of myosin with myopathic hamster protease results in substantial (more than 80%) removal of light chain 2 (LC2) with limited breakdown of the heavy chains. LC2-deficient myosin, purified by ion exchange chromatography, migrates as a single, monodisperse boundary in the analytical ultracentrifuge. The Ca2+- and EDTA-activated ATPases of LC2-deficient myosin are similar to those of the control and LC2-recombined myosins indicating that no denaturation occurred in its preparation. Double reciprocal plots for LC2-deficient, control, and LC2-recombined myosins reveal a biphasic behavior i.e. at actin concentrations above 11 microM, there is a sharp break in the 1/V versus 1/[actin] plots for all samples. The Vm values for LC2-deficient myosin are 50% lower (at low actin, Vm = 3.0 s-1, and at high actin, Vm = 4.2 s-1) than those for control myosin (Vm = 5.3 s-1 at low actin and 8.3 s-1 at high actin). Readdition of LC2 to LC2-deficient myosin restores the actin-activated ATPase to control levels. Electron microscopy of shadow cast preparations reveals a subtle difference between LC2-deficient myosin, and control or recombined myosin. In control and recombined myosins, S1 heads appear "pear"-shaped, whereas in LC2-deficient myosin, the S1 heads are rounder and display a "thinning" of mass in the "neck" region, suggesting that LC2 binds at the S1/S2 junction. Furthermore, removal of LC2 apparently influences the assembly of myosin into minifilaments, as revealed to a certain degree, by an increase in the width of the bare zone, accompanied by a decrease in the stability of these minifilaments.
Actins↗
Purification of human tissue plasminogen activator with Erythrina trypsin inhibitor.
Seeds of the legume Erythrina latissima contain a 20,000-dalton, single-chain protein that has been shown to inhibit the amidolytic activity of trypsin and tissue plasminogen activator. It had no comparable effect on urokinase. IC50 values of 1.1 X 10(-7) M for tissue plasminogen activator and 6.9 X 10(-10) M for trypsin were determined by titration. When coupled to agarose, the Erythrina inhibitor provided an effective reagent for affinity purification of tissue plasminogen activator from melanoma cell-conditioned tissue culture medium. Using this as a single-step procedure, 270-fold purified enzyme was reproducibly obtained with yields of 90% or greater. Both one- and two-chain forms of tissue plasminogen activator were purified. The enzyme migrated, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, as a predominant 72,000-dalton doublet with lesser amounts of immunochemically similar, 115,000- and 68,000-dalton components.
Cells, Cultured↗
Lipopolysaccharides from various Capnocytophaga strains possess potent Limulus amoebocyte lysate clotting activity.
Lipopolysaccharides (LPSs) were extracted by the hot phenol-water method from three ATCC strains (C. sputigena ATCC 33612, C. ochracea ATCC 33596, and C. gingivalis ATCC 33624) and three clinical isolates (C. sputigena TE-1, C. ochracea ONO-26, and C. gingivalis M-12). Endospecy was used to determine the Limulus amoebocyte lysate clotting activities. The activities of LPSs from Capnocytophaga strains were stronger than those of Escherichia coli, with the exception of the LPS from C. gingivalis M-12. Except for the LPS from C. sputigena TE-1, the SDS-PAGE analyses of these preparations showed slow-migrating and repeating ladder bands similar to the LPSs of E. coli and Salmonella typhimurium (wild type) and included both the core-lipid A region and various lengths of O-antigen. The LPS from C. sputigena TE-1 possessed fast-migrating bands and did not have an O-side chain.
Capnocytophaga↗
[Electrophoretic mobility of polypeptides in different strains on human influenza A and B viruses].
The method of electrophoresis in a single polyacrylamide gel plate was used for comparative study on virion polypeptides mobility in human influenza A and B virus strains. Molecular masses of individual polypeptides and their portion in the virion were determined. No variations in the migration speed of nucleoprotein (NP) and membrane protein (MP) were found in strains belonging to the same genus, but there were differences in the migration speed of these proteins in the genus A and genus B. Significant differences in migration and the content of glycoproteins, particularly of the heavy chain of hemagglutinin (HAI) in the genus A strain having different subtypes of hemagglutinin, including strains A/WS/33 (HONI), A/FM/1/47 (HINI), A/Sing/1/57 (H2N2), A/Port Chalmers/73 (H3N2), as well as in the genus B in strains B/Lee/40, B/Yamagata/1/73, and B/Johanesbourg/56. No differences in the mobility of glycoproteins in strains similar in the antigenic specificity of hemagglutinin and neuraminidase were found. On the basis of the comparative analysis of virion polypeptide electrophoregrams, three new strains on influenza A virus isolated in December, 1977, were identified as belonging to the species A (HINI).
Chemical Phenomena↗
Phase I safety and pharmacokinetic profile of an intercellular adhesion molecule-1 antisense oligodeoxynucleotide (ISIS 2302).
Healthy male volunteers received single or multiple intravenous infusions of an intercellular adhesion molecule-1 antisense phosphorothioate oligodeoxynucleotide, ISIS 2302, in a rising-dose (0.06-2.00 mg/kg infused over 2 hr), double-blind, placebo-controlled trial. Brief, dose-related increases in activated partial thromboplastin time were seen at the time of peak plasma concentration (C(max)). Clinically insignificant increases in C3a were seen after higher, repeated doses, but C5a, blood pressure and pulse were unaffected. No adverse events or other laboratory abnormalities were related to treatment with the drug. ISIS 2302 C(max) was linearly related to dose and occurred at the end of infusion. Plasma half-life for intact drug (53-54 min) and total oligonucleotide (67-74 min) were similar at the two doses (0.5 and 2.0 mg/kg) at which extensive pharmacokinetic data were collected. Nonlinear changes in area under the plasma concentration/time curve and steady-state volume of distribution with increasing dose suggested a saturable component to disposition. Metabolites co-migrating with n-1, n-2 and n-3 chain-shortened versions of ISIS 2302 appeared very rapidly in plasma, and disposition and metabolism appeared unaltered by repeated dosing. ISIS 2302 was well tolerated and behaved reproducibly with respect to plasma pharmacokinetics and expected side effects.
Adult↗
Capillary zone electrophoretic separation of C14-C18 linear saturated and unsaturated free fatty acids with indirect UV detection.
The baseline separation of eight saturated and unsaturated fatty acids of commercial interest was achieved in 15 min by counter-electroosmotic flow capillary zone electrophoresis (CZE), using dimethyl-beta-CD as a buffer additive. The background electrolyte consisted of 10 mM Tris-5 mM p-anisate (pH 8.1) and 1 mM dimethyl-beta-CD in a methanol-water (50:50, vol/vol) mixture. The presence of the cyclodextrin (CD) led to differential migration of critical pairs (i.e., fatty acids of common equivalent chain length or positional isomers). The absence of a highly absorbing chromophore moiety was circumvented through the use of p-anisate as a chromogenic co-ion in the carrier electrolyte. The conditions for indirect absorbance detection were optimized by taking into account the detector linearity and the spectral properties of both analytes and chromophore. A number of parameters influencing the resolution were also discussed, including overloading phenomenon and electroosmotic flow velocity modulation. Quantitative aspects of the method were tested through the analysis of three crude vegetable oils.
Absorption↗
Peripheral blood CD14(+) cells from healthy subjects carry a circular conformation of latent cytomegalovirus genome.
The majority of the human population harbors latent cytomegalovirus. Although CD14(+) peripheral blood mononuclear cells have been implicated as sites of latency, the conformation of the latent viral genome in these cells is unknown. In this study, the conformation of viral genomic DNA was assessed in CD14(+) cells from healthy virus seropositive carriers using an electrophoretic separation on native agarose gels in combination with polymerase chain reaction detection. Here we show that the viral genome migrates as a circular plasmid with a mobility equivalent to a circular 230-kb Shigella flexneri megaplasmid marker. Neither linear nor complex or integrated forms of the viral genome were detected. This report provides further evidence that the CD14(+) cell population is an important site of viral latency in the naturally infected human host. Detection of the viral genome as a circular plasmid during latency suggests that this virus maintains its genome in a manner analogous to other herpesviruses where latent viral genome conformation has been studied.
Carrier State↗
The complete structure of the trifoliin A lectin-binding capsular polysaccharide of Rhizobium trifolii 843.
The complete structure of the acidic, extracellular, capsular polysaccharide of Rhizobium trifolii 843 has been elucidated by a combination of chemical, enzymic, and spectroscopic methods, confirming an earlier proposed sugar sequence and assigning the locations of the acyl substituents. The polysaccharide was depolymerized by a lyase into octasaccharide units which were uniform in carbohydrate composition and linkage. These units also contained a uniform distribution of acetyl and pyruvic acetal [O-(1-carboxyethylidene)] groups, and half of them were further acylated with D-3-hydroxybutanoyl groups. A much smaller proportion (less than 5%) of the oligomers was further acylated by a second D-3-hydroxybutanoyl group. The locations of the subtituents were determined chemically and by J-correlated, 1H-n.m.r. spectroscopy, proton nuclear Overhauser effect (n.O.e.) measurements, double-rd structure of the carbohydrate chain were determined by methylation analysis using g.l.c.-m.s. fast-atom-bombardment mass spectrometry, and n.m.r. studies on the reduced, deacylated oligomer. Structural studies were supplemented by n.m.r. analyses on the original polymer. The oligosaccharides were found to be branched octasaccharides with four sugar residues in each branch, and the carbohydrate sequence agreed well with that expected from earlier work. In the abbreviated sequence and structure (1a), the sugar residues are labelled "a" through "h". The main chain (a-d) is composed of a 4-deoxy-alpha-L-threo-hex-4-enopyranosyluronic acid group (a) that is linked to O-4 of a 3-O-acetyl-D-glucosyluronic acid residue (b) which is beta-linked to O-4 of a D-glucosyl residue (c). Residue c is beta-linked to O-4 of the branching D-glucose residue (d). The side chain consists of a substituted D-galactosyl group (h) which is beta-linked to O-3 of residue 9 of a beta-(1----4)-linked D-glucose trisaccharide (fragment e-f-g). The reducing end of the resulting tetrasaccharide (e-f-g-h) is beta-linked to O-6 of the branching D-glucose residue (d). In the native polymer, this branching residue is alpha-linked to O-4 of the modified D-glucuronic acid residue (a) which is the unsaturated sugar in the oligomer. A small proportion of the O-2 atoms of the acetylated D-glucosyluronic acid residues is acetylated because of ester migration. The two terminal sugars (g and h) of the branch chain bear 4,6-O-(1-carboxyethylidene) groups. The D-galactosyl groups of half of the oligomers are acylated by D-3-hydroxybutanoyl groups at O-3.(ABSTRACT TRUNCATED AT 400 WORDS)
Carbohydrate Sequence↗
Up-regulation of transcription of smooth muscle myosin alkali light chain by ethanol in human breast cancer cells.
Both epidemiological and experimental studies indicate that ethanol is a tumor promoter and that chronic ethanol exposure enhances metastasis of breast cancer cells, and with an in vitro model (T47D human breast cancer cells), we have previously demonstrated that ethanol exposure stimulated the migration of breast cancer cells. In the present study, differential display reverse transcription polymerase chain reaction was used to identify ethanol-responsive genes in T47D cells. Three differentially displayed, ethanol-responsive gene fragments were identified, and their expression was confirmed by Northern blot hybridization. Sequence analysis revealed that one cDNA fragment represented the myosin alkali light chain (MLC 1sm) of human smooth muscle. The expression of MLC 1sm was found to be significantly higher in breast cancer cells than in normal mammary epithelial cells. With T47D cells, ethanol induced an additional duration- and concentration-dependent up-regulation of MLC 1sm. At 400 mg/dl, an ethanol-mediated increase was evident at 6 h (55% increase), peaked at 24 h (2.7-fold increase) following exposure, and diminished thereafter. At pharmacologically relevant concentrations (e.g., 100 mg/dl), ethanol produced a significant increase of MLC 1sm expression, and progressively higher ethanol concentrations resulted in more up-regulation. The half-life of MLC 1sm mRNA was not altered, however, the transcription rate of MLC 1sm was significantly increased by ethanol. MLC is a structural component of the cytoskeleton of eukaryotic cells, and it plays critical roles in the regulation of cell shaping, movement, and growth. Thus, ethanol-mediated up-regulation of MLC may be an underlying molecular mechanism for its tumor promoting effect.
Blotting, Northern↗
The role of fibroblasts in the modulation of integrin-dependent interactions between the gastric cell line HGT-1 and fibronectin.
Fibronectin plays an important role in gastric cancer progression. However, little is known about the microenvironmental factors modulating integrin-dependent interactions between gastric cancer cells and fibronectin. We therefore studied the regulation by fibroblasts of the integrin-dependent adhesion and migration of the gastric cancer cell line HGT-1 onto fibronectin. We first determined, by immunofluorescence, immunoblotting and flow cytometry, that HGT-1 cells expressed alpha3, alpha5, alpha6, alphaV and beta1 integrin chains, and the alphaVbeta3 and alphaVbeta5 dimers. We verified that HGT-1 cells xenografted to the immunosuppressed newborn rat retained the integrin repertoire detected in vitro and were able to induce the formation of tumors rich in fibronectin. By using an in vitro assay in the presence of neutralizing antibodies, we verified that HGT-1 adhesion and migration onto fibronectin involved beta1, alphaV and alpha5 integrin chains; we verified, by using an in situ adhesion test to rat gastric wall frozen sections, that in situ HGT-1 adhesion to fibronectin was integrin dependent. In coculture experiments, we showed that organ-specific fibroblasts from stomach, lung and dermis were able to induce, in a site-specific manner, the expression of beta1, alpha5 and alphaV integrin chains in HGT-1 cells, their integrin-dependent adhesion and migration on fibronectin and their capacity to secrete oncofetal fibronectin. In conclusion, our results show the capacity for tissue-derived fibroblasts to modulate the integrin-dependent interactions between the gastric cell line HGT-1 and fibronectin. They strongly suggest that, in gastric cancer, stromal fibroblasts contribute to promote fibronectin-mediated local invasion by tumor cells.
Animals↗