Macromolecular Component (of a Rotaxane)

A calf serum ultrafiltrate fraction permitted growth for at least 3.5 generations, including one subculture, of MRC-5 cells in defined medium in the absence of whole serum. The active material has a molecular weight of 10 000 Daltons or less. This suggests that there may be no requirement for a large macromolecular component of serum. The ultrafiltrate was assayed by maximum cell yield from a serum-limited inoculum in a defined medium containing non-limiting amounts of vitamins, amino acids, glucose, a 68-component supplement, iron and methylcellulose. The levels of vitamins, amino acids and glucose were based on quantitative measurements of uptake and the levels of the other components by minimum amount required for maximum yield in defined medium without ultrafiltrate or serum. With excess ultrafiltrate maximum cell yield was limited by the defined part of the medium, probably the supplement. The cell doubling time in defined medium with ultrafiltrate fractions was 70 h compared with 27 h in the medium with serum. Excess ultrafiltrate did not inhibit growth. The lowered growth rate is attributed to a nutritional deficiency in the supplement.

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Organic colloids and their influence on low-pressure membrane filtration

Water Science & Technology ◽

10.2166/wst.2004.0728 ◽

2004 ◽

Vol 50 (12) ◽

pp. 311-316 ◽

Cited By ~ 9

Author(s):

C. Laabs ◽

G. Amy ◽

M. Jekel

Keyword(s):

Wastewater Treatment ◽

Glass Fiber ◽

Membrane Filtration ◽

Membrane Surface ◽

Treatment Plant ◽

Low Pressure ◽

Colloidal Solutions ◽

Cake Layer ◽

Stirred Cell ◽

Macromolecular Component

Wastewater treatment by low-pressure membrane filtration (MF and UF) is affected to a large extent by macromolecules and colloids. In order to investigate the influence of organic colloids on the membrane filtration process, colloids were isolated from a wastewater treatment plant effluent using a rotaryevaporation pre-concentration step followed by dialysis. Stirred cell tests were carried out using redissolved colloids, with and without additional glass fiber filtration. After constant pressure membrane filtration of 190 L/m2, the initial flux had declined by 50% for colloids > 6-8 kD (glass fiber filtered) with a hydrophilic MF membrane and for colloids >12-14 kD (glass fiber filtered) with a hydrophobic MF membrane. For the non-filtered colloidal solutions, the flux decline was even steeper with the flux being below 10% of the initial flux after 190 L/m2 were passed through the membranes. As with larger particles, colloids form a filtration cake layer on top of the membrane surface when used as isolates without prior filtration. This filtration cake is easily removed during backwashing. However, polysaccharides as a macromolecular component of the colloid isolate cause severe fouling by the formation of a gel layer on the membrane surface that is difficult to remove completely.

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COMPARISON OF MACROMOLECULAR COMPONENT DISTRIBUTIONS IN OSTEOARTHRITIC AND HEALTHY CARTILAGES BY FOURIER TRANSFORM INFRARED IMAGING

Journal of Innovative Optical Health Sciences ◽

10.1142/s179354581350048x ◽

2013 ◽

Vol 06 (04) ◽

pp. 1350048 ◽

Cited By ~ 2

Author(s):

JIANHUA YIN ◽

YANG XIA ◽

ZHIYAN XIAO

Keyword(s):

Fourier Transform ◽

Infrared Imaging ◽

Early Stage ◽

Clinical Signs ◽

Fourier Transform Infrared ◽

Osteoarthritic Cartilage ◽

Tissue Degradation ◽

Fourier Transform Infrared Imaging ◽

Macromolecular Component ◽

Clear Change

Fourier transform infrared imaging (FTIRI) was used to examine the depth-dependent content variations of macromolecular components, collagen and proteoglycan (PG), in osteoarthritic and healthy cartilages. Dried 6 μm thick sections of canine knee cartilages were imaged at 6.25 μm pixel-size in FTIRI. By analyzing the infrared (IR) images and spectra, the depth dependence of characteristic band (sugar) intensity of PG show obvious difference between the cartilage sections of (OA) and health. The result confirms that PG content decreases in the osteoarthritic cartilage. However, no clear change occurs to collagen, suggesting that the OA influences little on the collagen content at early stage of OA. This observation will be helpful to further understand PG loss associated with pathological conditions in OA, and demonstrates that FTIRI has the potential to become an important analytical tool to identify early clinical signs of tissue degradation, such as PG loss even collagen disruption.

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Interstitial spaces are continuous across tissue and organ boundaries in humans

10.1101/2020.08.07.239806 ◽

2020 ◽

Author(s):

Odise Cenaj ◽

Douglas H. R. Allison ◽

R Imam ◽

Briana Zeck ◽

Lilly M. Drohan ◽

...

Keyword(s):

Fibrous Tissue ◽

The Body ◽

Cell Trafficking ◽

Molecular Signaling ◽

Extracellular Matrix Components ◽

Tattoo Pigment ◽

Flow Through ◽

Macromolecular Component ◽

Fibrous Tissues ◽

Organ Boundaries

AbstractBodies have “reticular networks” comprising collagens, elastin, glycosaminoglycans, and other extracellular matrix components, that are continuous within and around all organs. Fibrous tissue coverings of nerves and blood vessels create structural continuity beyond organ boundaries. We recently described fluid flow through such human fibrous tissues. It remains unclear whether these interstitial spaces are continuous through the body or are discontinuous, confined within individual organs. We investigated IS continuity using two approaches. Non-biological particles (tattoo pigment, colloidal silver) were tracked within colon and skin interstitial spaces and into adjacent fascia. We also exploited hyaluronic acid, a macromolecular component of interstitial spaces. Both techniques demonstrate continuity of interstitial spaces within and across organ boundaries, including within perineurium and vascular adventitia traversing organs and the spaces between them. We suggest a body-wide network of fluid-filled interstitial spaces with significant implications for molecular signaling, cell trafficking, and the spread of malignant and infectious disease.

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Macromolecular Glucosamine-Containing Component of the Surface of Cultivated Mouse Cells

Journal of Cell Science ◽

10.1242/jcs.7.2.337 ◽

1970 ◽

Vol 7 (2) ◽

pp. 337-355

Author(s):

K. ONODERA ◽

ROSE SHEININ

Keyword(s):

Plasma Membrane ◽

Cell Division ◽

Cell Surface ◽

Plating Efficiency ◽

Transformed Cells ◽

3T3 Cells ◽

Vital Stain ◽

Surface Component ◽

Mouse Cells ◽

Macromolecular Component

It has been demonstrated that a glucosamine-containing macromolecular component of the cell surface of 3T3 mouse cells, and SV40-transformed cells, is released from cells by treatment with trypsin under conditions in which the plasma membrane remains functionally intact. This was shown by the fact that the treated cells could be cloned with high plating efficiency and remained impermeable to the vital stain, erythrocin. A method for specifically marking this surface component has been devised based on the finding that in 3T3 cells growing synchronously after subculture by trypsin maximum incorporation of glucosamine into this material occurs 12-13 h thereafter. Of the total radioactive glucosamine incorporated into macro-molecular cell constituents, over 80% was recovered in surface component. Studies on the biosynthesis of surface component revealed that this was periodic during a cycle of cell duplication, with an increased rate of formation immediately after cell division. It was found that the surface component of 3T3 cells differed from that of SV40-transformed cells.

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THE STRUCTURE OF ACTIN-RICH FILAMENTS OF MUSCLES ACCORDING TO X-RAY DIFFRACTION

The Journal of Cell Biology ◽

10.1083/jcb.2.1.71 ◽

1956 ◽

Vol 2 (1) ◽

pp. 71-85 ◽

Cited By ~ 86

Author(s):

Cecily Cannan Selby ◽

Richard S. Bear

Keyword(s):

Large Scale ◽

Adductor Muscle ◽

X Ray Diffraction ◽

Cell Width ◽

X Ray ◽

Filament Axis ◽

Repeat Structure ◽

Diffraction Patterns ◽

The Individual ◽

Macromolecular Component

From analysis of moderate- to small-angle x-ray diffraction patterns, in the light of similar experience with paramyosin, has been derived the following description for the structure of actin-rich filaments in "tinted" portions of the adductor muscle of the clam, Venus mercenaria: 1. Some 11 diffraction maxima, widely streaked along layer lines and occurring at moderate diffraction angles (spacings 7 to 60 A) appear to be accounted for as (hk) reflections of a net whose cell elements are, for dry material: a ≑ 82 A, b = 406 A (filament axis identity period), and γ ≑ 82° (angle between a and b axes). These reflections follow a selection rule which indicates that the net cell is non-primitive and contains 15 equivalent locations (nodes) arranged as shown in Fig. 5. An alternative net has b' = 351 A and 13 nodes per cell. 2. Another interpretation rolls the net into a large-scale helix and places the 15 (or 13) nodes along 7 (or 6) turns of a helical locus projecting 406 (or 351) A along the filament axis. Whether considered to be built of planar-net or helix-net cells, the individual filament contains a single cell width transverse to its axis. Transverse filament dimensions are, therefore, in either case similar (50 to 100 A). 3. Consideration of existing electron-optical, physicochemical, and x-ray diffraction data regarding isolated actin suggests that the net cell is built of rods, each containing in cross-section from one to four actin molecules which run parallel to or twisted about rod axes that extend at 12° to the filament axis along the (21) diagonals of the cell. Depending on monomer shape, 2 to 15 monomers furnish length to reach across two cells, and the actin molecules are built into each rod in such a way as to repeat (or nearly repeat) structure 15 (or 13) times along the double cell length. Further details of intra-rod structure cannot be suggested because of lack of wide-angle diffraction information. 4. The actin system is sensitive to treatment of the muscle with ethanol. Concentrations of 5 per cent or greater abolish the net reflections. Other solvents—water, benzene, ether, pyridine, acetone—do not alter the pattern materially. 5. Two other reflections, occurring at the first and second layer lines of an axial periodicity of about 400 A, do not clearly belong to the actin-net system. They represent either a superstructure built upon the filaments by parts of the actin molecules themselves or by incorporated other molecular species, or they arise from an additional macromolecular component (possibly myosin, or its homologues or fractions) of similar axial periodicity.

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OESTROGEN-INDUCIBLE UTERINE PROGESTERONE RECEPTORS. CHARACTERISTICS IN THE OVARIECTOMIZED IMMATURE AND ADULT HAMSTER

Acta Endocrinologica ◽

10.1530/acta.0.0800344 ◽

1975 ◽

Vol 80 (2) ◽

pp. 344-354 ◽

Cited By ~ 19

Author(s):

J. R. Reel ◽

Y. Shih

Keyword(s):

Body Weight ◽

Actinomycin D ◽

Progesterone Receptors ◽

Molar Ratio ◽

Density Gradient Ultracentrifugation ◽

Limited Capacity ◽

Maximum Increase ◽

Protamine Sulphate ◽

Macromolecular Component ◽

Adult Hamster

ABSTRACT In order to characterize the uterine progesterone-binding proteins of oestrogen-primed and unprimed, ovariectomized immature and adult golden hamsters, cytosols were incubated with [3H] progesterone and/or other steroids and analyzed by sucrose-glycerol density gradient ultracentrifugation. Progesterone-binding components with sedimentation coefficients of 7S and 4.5S were found in the uterine cytosols, but not in the cytosols from the hypothalamus, pituitary, diaphragm, or small intestine. Oestradiol-17β markedly elevated the level of 7S uterine receptor and this increase appeared to be due to new receptor synthesis, since actinomycin D and cycloheximide blocked this response. Fifty to 100 μg of oestradiol-17β per kg body weight was found to promote a maximum increase in the 7S macromolecular component. The 7S receptor showed a tendency to saturate at 1 × 10−7 m [1,2-3H] progesterone, indicating limited capacity. At a molar ratio of 100:1, unlabelled progesterone competed effectively for 7S and 4.5S [3H]progesterone binding, whereas 5α-pregnane-3,20-dione, oestradiol-17β and testosterone did not. Moreover, [1,2-3H] cortisol and [1,2-3H] corticosterone did not bind to the 7S receptor, implying steroid specificity. CI-628, a non-steroid oestrogen antagonist, completely prevented [6,7-3H] oestradiol-17β binding to its 8.5S uterine cytosol receptor, but was entirely without effect on 7S and 4.5S [3H] progesterone binding. Pronase, but not DNase or RNase, abolished 7S and 4.5S progesterone binding, suggesting that the binders are at least in part protein. Protamine sulphate and p-hydroxymercuribenzoate also obliterated 7S binding, implying that this receptor may be an acidic protein which contains sulfhydryl groups that are necessary for progesterone binding.

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Active accumulation of tetracycline by Escherichia coli

Biochemical Journal ◽

10.1042/bj1160287 ◽

1970 ◽

Vol 116 (2) ◽

pp. 287-297 ◽

Cited By ~ 24

Author(s):

T. J. Franklin ◽

B. Higginson

Keyword(s):

Escherichia Coli ◽

High Speed ◽

Osmotic Shock ◽

Significant Proportion ◽

Supernatant Fraction ◽

High Concentration ◽

Temperature Dependent ◽

Experimental Conditions ◽

E Coli ◽

Macromolecular Component

1. At low concentrations of tetracycline (10μg/ml) net accumulation of the drug by Escherichia coli cells ceased after 7–10min. 2. At higher concentrations of tetracycline (>30μg/ml) the period of net accumulation of the drug was significantly extended. 3. The efflux of tetracycline from E. coli cells transferred from medium containing 10μg of tetracycline/ml to drug-free medium was a rapid temperature-dependent process and was accelerated by 2,4-dinitrophenol. 4. As the concentration of tetracycline in the preloading phase was increased, the rate of subsequent efflux of the drug progressively declined. The efflux of drug from cells preloaded in medium containing 200μg of tetracycline/ml was negligible, although efflux was readily provoked by 2,4-dinitrophenol, by N-ethylmaleimide or by omission of glucose from the medium. 5. The initial rate of uptake of tetracycline by E. coli cells was linearly proportional to the concentration of tetracycline in the medium up to the maximum concentration of drug obtainable under the experimental conditions used (400μg/ml, 0.83mm). 6. Although N-ethylmaleimide strongly inhibited the accumulation of tetracycline by E. coli, no evidence was obtained for the direct involvement of thiol groups in the transport process. It was concluded that N-ethylmaleimide inhibited accumulation by interruption of the energy supply of the cells. 7. Osmotic shock of E. coli cells did not significantly affect the influx of tetracycline, but promoted both efflux of tetracycline and cell lysis in cells treated with a high concentration of tetracycline. 8. A study of the distribution of tetracycline among the subcellular fractions of penicillin-induced spheroplasts preincubated with various concentrations of tetracycline indicated that 60–70% of the accumulated tetracycline was in the high-speed supernatant fraction. Sephadex chromatography showed that the tetracycline of this fraction was present as the free drug. Sephadex chromatography of a detergent extract of the membrane fraction, however, indicated that a significant proportion of the tetracycline radioactivity of this fraction was apparently bound to some macromolecular component. 9. Cellulose phosphate paper chromatography of cold-acid extracts of spheroplasts preloaded with tetracycline indicated that the accumulated drug was chemically unchanged. 10. Membrane preparations isolated from osmotically lysed penicillin-induced spheroplasts showed a temperature-dependent binding of tetracycline that was not energy-dependent and was not inhibited by N-ethylmaleimide. The binding process was stimulated by omitting Mg2+ from the medium, but conversely was profoundly inhibited by EDTA. 11. The relevance of these findings to the probable mechanism of active tetracycline accumulation by E. coli is discussed.

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