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PubMed1977

[Experiences with the postoperative intranasal long term splinting of the septum (author's transl)].

Reference is made to the stabilizing function of the septal cartilage and the incalculability of its reaction after injury or surgical treatment. Apart from various forms of tampons particularly the use of cut polyethylen splints for long term splinting of the septum has to be mentioned. We emphasize their stabilizing effect in the healing phase, the compatability with the patient, the application possibilities and finally surgical details. Even after a period of 3 weeks observation, we can see active ciliated epithelium by microscopic examination, a transformation into inferior squamous epithelium does not take place.

Humans↗
PubMed1979

A biochemical and ultrastructural comparison of Triton X-100 models of normal and transformed cells.

We have compared the two-dimensional gel profiles of Triton models of normal rat kidney (NRK) cells and their Kirsten viral transformant, 442. Several protein differences were detected. The models of the transformed line lacked five acidic polypeptides and possessed a much higher intermediate filament to actin ratio. Scanning microscopy reveals significant ultrastructural differences in these models, with the NRK line exhibiting a much more filamentous structure. In addition, nuclease treatment of NRK models causes a dramatic change in their scanning image while the 442 models are unaffected. Nuclease treated models lack microfilaments and appear to contain only intermediate filaments, although actin is still a prominent protein constituent.

Actins↗
PubMed2026

Acinetobacter guillouiae, a lipolytic strain isolated from sludge capable of partially depolymerising polyethylene terephthalate: genomic, proteomic, and biochemical insights.

Acinetobacter guillouiae I-MWF was isolated by incubating amorphous polyethylene terephthalate (PET) film in sludge samples. The strain partially depolymerised PET powder with 11.3% crystallinity, as confirmed by FT-IR, HPLC-UV, and LC-MS analyses. Extracellular enzymes released terephthalic acid (TPA), mono(2-hydroxyethyl) terephthalate (MHET), and bis(2-hydroxyethyl) terephthalate (BHET). Genomic analysis identified 18 putative extracellular hydrolases, including lipases and esterases, each with a conserved catalytic triad. Proteomic profiling revealed expression of two triacylglycerol lipases and two additional lipase-family proteins when the strain was cultivated with PET or a PET-Tween 80 mixture. These enzymes were cloned in Escherichia coli, but most formed insoluble, inactive inclusion bodies, and one was not expressed. Molecular modelling highlighted structural features likely to influence their catalytic interaction with PET. Although the strain partially depolymerised PET powder, it was unable to grow on PET, TPA, or ethylene glycol, indicating that PET depolymerisation occurs as a side activity rather than supporting growth. Instead, A. guillouiae displayed strong lipolytic activity and a clear preference for lipid-based substrates, achieving its highest growth with Tween 80. A lipid transporter was also expressed under these conditions, suggesting adaptation to hydrocarbon-rich environments. These findings indicate that A. guillouiae I-MWF can mediate partial PET depolymerisation without assimilating the resulting monomers, while preferentially growing on lipid-like substrates.

Acinetobacter↗
PubMed1978

[Electron microscopic study of mammalian somatic cell fusion under the action of polyethylene glycol].

An electron microscope study of heterokaryons and synkaryons, obtained after the treatment of suspension of human embryonic fibroblasts and cultured fibroblasts of Chinese hamster (clone M151) with polyethylene glycol (PEC, m. v. 6000) has shown that in 15 minutes after the administration of PEG, the cell agglutination and disappearance of plasma membranes between cells takes place. It is not obvious, however, how PER is passing through the cell envelope, but the similar action of PEF towards the inner cell membranes was observed. In the heterokaryons, the nuclear fusion may occur not only during mitosis but also in interphasic cells. Therefore heterokaryons transform to synkaryons extremely synchroneously. During 20 hours the majority, and during 48 hours all the heterokaryons are seen transformed to synkaryons.

Animals↗
PubMed1978

Effects of acidified fetal bovine serum on the fibrinolytic activity and growth of cells in culture.

The fibrinolytic activity of cells in culture varied with the type of serum employed in the growth medium. Degradation of iodinated fibrin occurred slowly when Rous sarcoma virus-transformed chick embryo fibroblasts were grown in medium containing fetal bovine serum (FBS), and rapidly when chicken serum was employed. This difference reflected the low plasminogen and high inhibitor content of FBS. The inhibitors were found to be serum macromolecules that were precipitated with ammonium sulfate or polyethylene glycol, and were inactivated by boiling or upon exposure to acidic conditions. No inhibitor activity was detected in fetuin, one of the major proteins present in FBS. Acidified FBS was similar to chicken serum in that both supported high rates of cell-mediated fibrinolytic activity. Although virally transformed hamster, mouse and chicken cells grew well in acid-treated FBS, their normal counterparts did not. Apparently, acifification resulted in the formation of materials that were toxic to normal cells. These agents rapidly blocked cellular DNA synthesis.

Animals↗
PubMed1978

[Growth of cultured blood cells in the presence of the cryoprotector polyethylene oxide 400].

The effect of polyethylene oxide 400 (PEO-400) cryoprotector on the mitotic activity of human peripheral blood leukocytes stimulated with PHA was studied in a culture. The cytologic peculiarities of the blood cell growth on addition of PEO-400 prior to cultivation are manifested in the preservation of the transformation capacity and mitosis despite a significant reduction of the mitotic activity in comparison with control cultures.

Cells, Cultured↗
PubMed1979

Studies of a large transformation-increased membrane protein in the BHK21 cell system.

We have recently described in BHK cells a plasma membrane protein of molecular weight 177,000, which is significantly increased in Hamster Sarcoma Virus-transformed cells (Lage-Davila, A. and Montagnier, L. (1977) Biochem. Biophys. Res. Commun. 79, 577--584). We present now a study of proteins from purified plasma membrane fractions in the same pair of clones. Solubilization conditions, cross-linking experiments, metabolic labelling and enzymatic radioiodination allow to characterize this 177,000 transformation-increased protein as an integral membrane glycoprotein partially exposed at the outer cell surface. Additional information on other membrane proteins in this system is also given.

Animals↗
PubMed1978

Large-scale production, concentration and purification of Rous Sarcoma Virus in tissue culture.

A method is described for long-term standard production of purified virus from cultures of PR-RSV-C-transformed chicken cells. The mean yields were 4.91 mg of purified virus per liter of culture medium. Cells were grown in long-term cultures for 26 weeks. A combination of polyethylene glycol 6 000 precipitation and zonal centrifugation has been found satisfactory for virus concentration and purification.

Animals↗
PubMed1978

[Controlled trial of levamisole in rheumatoid arthritis. Clinical and immunological study of 22 cases (author's transl)].

The results of a controlled trial in 22 patients indicated that levamisole, administered in a dose of 150 mg per day for 2 months, was more effective than a placebo on the clinical symptoms and signs of rheumatoid arthritis. Side effects were seen in 8 of the 12 patients treated with levamisole. They necessitated the premature interruption of treatment in three, but were never serious (no cases of agranulocytosis were seen). In the group treated with levamisole, there was a slight decrease in sedimentation rate, a significant fall in levels of the C3 fraction of serum complement and of circulating immune complexes (detected by polyethylene glycol), and a significant increase in cutaneous reaction to tuberculin and to candidin. By contrast, there were no significant variations in levels of rheumatoid factor, serum immunoglobulins, C4 fraction of complement, lymphocyte transformation indices in the presence of six dilutions of phytohaemagglutinin, nor in the percentages of T and B lymphocytes. The effectiveness of levamisole in rheumatoid arthritis would appear to be demonstrated, but its mode of action remains open to discussion, in the absence of any definite correlation between therapeutic activity and the immunostimulant effects of the drug.

Antigen-Antibody Complex↗
PubMed1977

Enhancement of weak mixed lymphocyte-type reactions by hydrophilic polymers.

Two hydrophilic polymers, dextran and polyethylene glycol, were found to enhance in vitro MLR-type reactions which are weak or nonexistent in normal culture media. BALB/c and C57BL/6 thymocytes were cultured for 4 days in Eagle's MEM + 10% FCS, with or without the x-irradiated lymphomas LSTRA AND EL-4, respectively. By thymidine incorporation no stimulation was observed with EL-4 in plain culture whereas occasionally a very small stimulation was observed with LSTRA. Four percent dextran (w/v, m.w. greater than or equal to 40,000) improves stimulation (E/C) by about 2-fold. The effect of polyethyleneglycol m.w. 6,000 (PEG-6) is much more pronounced. At the optimal concentration of 4 to 5%, PEG-6 causes an increase of 5- to 20-fold in the stimulation index. The PEG-6 effect can also be observed microscopically by the appearance of numerous blasts clustered around the tumour cells. PEG-6 by itself has little effect on thymocytes in the absence of tumor cells. In the case of one-way allogeneic MLR under suboptimal ratios, dextrans (m.w. greater than or equal to 40,000) enhance the reaction dramatically. We speculate that these effects are occurring via a change in the solvent (such as solvent exclusion) in a way which enhances immunologic interactions under conditions which are tolerable to cells in vitro.

Animals↗
PubMed2026

Towards microplastic bioremediation: Fungal degradation of pristine and pretreated high-density polyethylene and polystyrene.

Microplastic (MP) contamination has become a significant ecological issue because of its enduring existence in the ecosystem and its possible negative impacts. Therefore, using degrading strategies to eliminate these stubborn polymers has been a subject of scientific research. However, the currently used degradation methods are relatively inefficient. Given the pervasiveness of High-Density Polyethylene (HDPE) and Polystyrene (PS) and their resistance to biodegradability, disposal strategies are critical and must be addressed. This manuscript examines the biodegradation of pristine and UV-treated HDPE and PS MPs by Aspergillus flavus species in minimal growth media over 70 days. The maximum weight loss observed at 70 days for pristine HDPE and PS in sole carbon source (SCS) media was (29.33 ± 0.28) % and (17.67 ± 0.35) %, respectively. Whereas, for UV-treated HDPE and PS MPs, the % weight reduction was (33 ± 0.21) % and (25 ± 0.19) %, respectively. UV-treated MPs exhibited greater weight reduction, as UV induced oxygenated functional groups enhance polymer susceptibility to enzymes, thereby promoting biodegradation. HDPE MPs typically show a higher proportion of particles in the lower size range compared to PS MPs. This assertion was based on the weight loss, particle size distribution, and SEM analysis. Furthermore, chemical changes were evaluated using Fourier transform Infrared Spectroscopy (FTIR) analysis, which also displayed chemical oxidation occurring during biodegradation. Liquid Chromatography-Mass Spectrometry (LC-MS) results indicate that UV pretreatment enhances biodegradability by promoting chain scission. These findings further suggest that this fungus's natural and ubiquitous occurrence in terrestrial and marine environments may actively contribute to MP biodegradation while requiring few nutrients.

Microplastics↗
PubMed1977

Effects of oral and intrauterine administration of contraceptives on the uterus.

Combined regimen contraceptive steroids produce precocious endometrial secretion, followed by involution leading to a suppressed endometrium with small tubular glands and failure of spiral arterioles to develop; decidua-like stromal changes are dose related as is dilatation of venules. Thrombosis of the latter, perhaps estrogen mediated, leads to local tissue infarction and is the proximate cause of "breakthrough bleeding". Sequential regimen contraceptive steroids lead to retarded endometrial secretion, failure of spiral arterioles to develop, and a weak decidua-like stromal transformation. Contraceptive steroids occasionally produce polypoid lesions of the endocervix with atypical microglandular hyperplasia. There are conflicting reports about the effects of contraceptive steroids on the squamous epithelium of the exocervix, but they neither protect against cancer nor cause it in the usually accepted sense. Uterine leiomyomas may exhibit increased cellularity and bizarre, hyperchromatic nuclei or mutinucleation in women receiving contraceptive steroids. Both polyethylene and metal-containing intrauterine devices may initiate inflammatory responses in the endometrium varying from mild to severe, related to the time the device has been in contact with the mucosa. Salpingitis and ectopic pregnancy are increased in frequency in device users.

Adult↗
PubMed1978

[Formation of heterosymplasts in human reticular cell cultures].

The cell fusion has been studied in human reticular cell cultures J-96 and J-41 treated with the Sendai virus or with polyethylene glycol 1000 and 6000. The J-96 cells have a high alkaline phosphatase activity, in J-41 cells the enzyme is not detectable. No heterogenous alkaline phosphatase activity was seen in the protoplasm of symplasts 18 hours after virus cell fusion. It has been shown with polyethylene glycol treatment that during the fusion of cells J-96 and J-41 the enzyme activity was spreading over the symplast protoplasm.

Alkaline Phosphatase↗
PubMed2024

Metagenomic analysis reveals gene taxonomic and functional diversity response to microplastics and cadmium in an agricultural soil.

Both microplastics (MPs) and heavy metals are common soil pollutants and can interact to generate combined toxicity to soil ecosystems, but their impact on soil microbial communities (e.g., archaea and viruses) remains poorly studied. Here, metagenomic analysis was used to explore the response of soil microbiome in an agricultural soil exposed to MPs [i.e., polyethylene (PE), polystyrene (PS), and polylactic acid (PLA)] and/or Cd. Results showed that MPs had more profound effects on microbial community composition, diversity, and gene abundances when compared to Cd or their combination. Metagenomic analysis indicated that the gene taxonomic diversity and functional diversity of microbial communities varied with MPs type and dose. MPs affected the relative abundance of major microbial phyla and genera, while their coexistence with Cd influenced dominant fungi and viruses. Nitrogen-transforming and pathogenic genera, which were more sensitive to MPs variations, could serve as the indicative taxa for MPs contamination. High-dose PLA treatments (10%, w/w) not only elevated nitrogen metabolism and pathogenic genes, but also enriched copiotrophic microbes from the Proteobacteria phylum. Overall, MPs and Cd showed minimal interactions on soil microbial communities. This study highlights the microbial shifts due to co-occurring MPs and Cd, providing evidence for understanding their environmental risks.

Soil Microbiology↗
PubMed1978

[Histochemical and histoenzymatic study of experimental endarteritis in rabbits. I. Femoral endarteritis].

The parietal reaction after placing a cuff of polyethylene around the femoral artery has been studied in 18 (2,5 - 3 months old) male rabbits by using histologic, histochemical (4 macromolecular substances) and histoenzymatic techniques (16 enzymatic activities). Studies were performed on the 1st, 3rd, 5th, 15th and 21st day, and every 15 days during the 3 months of the experiment. This process induced rapidly in each animal a parietal reaction with adventitial oedema (1st day), hypoxia of the media (1st -5th day), cytoenzymatic activation followed by a cellular transformation and proliferation of the intima-media, that forms a diffuse intimal thickening (adaptation). Most cells of the thickening were, by their enzymatic activities, quite comparable to immature smooth muscle cells, which probably emigrated from the media: intense LDH, NADH2 - TR; moderate G6P-DH, SDH, NADPH2 - TR, alpha-GP-DH, ATP/ase; weak ICHD, beta-HB-DH. Moreover, some reactions (accentuation of beta-Glu/ase, UDGP-DH, Glu-DH, 5'N/ase) besides suggested the active participation of the cells in the production of extracellular conjonctive constituents, because the histochemical studies revealed the presence of metachromatic glycosamino-glycanes and positive APS substances during the edification of the diffuse intimal thickening. In advanced thickening, an histoenzymatic duality was observed, that might prove the double origin of the thickening cells: some superficial cells had the enzymatic characteristics of endothelial cells (increased activity of aerobic oxydoreductases). At every stage of the study, the thickening cells differed from the atherocytes by a lack of lipids in their cytoplasm.

Animals↗
PubMed1979

Genetic recombination in fused spheroplasts of Providence alcalifaciens.

Spheroplasts of Providence alcalifaciens strain P29 auxotrophs were prepared by combined treatment with glycine and lysozyme-EDTA. About 15% of spheroplasts had areas of cytoplasmic membrane exposed where cell wall was absent. The spheroplasts of different auxotrophs were mixed pairwise and fusion was attempted with polyethylene glycol or nascent calcium phosphate. After spheroplasts had regenerated to bacterial forms selection was made for recombinants. Recombinants arose at frequencies of 3.8 X 10(-6) to 1.7 X 10(-7) per spheroplast initially present, by both methods of fusion. The frequency was strongly dependent on the number of chromosomal loci used in selection. The possible order of five loci was determined and this corresponded to that on the closely related Proteus mirabilis chromosome. Control experiments excluded possibilities of auxotrophic reversion, conjugation, transformation, transfection or transduction as explanations of the results. Analysis of prototrophic clones yielded stable prototrophs or mixtures of stable prototrophs and stable recombinants. Parental types were not encountered. Unselected markers segregated among recombinants. It was concluded that the formation of recombinant bacteria was due to spheroplast fusion and that only stable products of the very temporary heteroploid state were haploid recombinants. The low frequency of recombination was ascribed to the limited number of spheroplasts with areas of exposed cytoplasmic membrane.

Cell Wall↗
PubMed1979

X-ray diffraction studies of fibers and crystals of deoxygenated sickle cell hemoglobin.

Paracrystalline fibers of deoxygenated sickle hemoglobin in erythrocytes or concentrated solutions exhibit a phase transformation to a fully crystalline state. X-ray diffraction patterns of the fiber and crystallites are similar except in two respects: the equatorial spacings of the fibers suggest that they pack into a square lattice with a = 220 A, whereas those of the crystals can be indexed on the basis of a net of 187 A by 54 A, and the second-order near-meridional reflections are strong on the fiber pattern but weak on that of the crystallites. The crystallites are isomorphous with single crystals grown in polyethylene glycol solution at pH 4.5 whole structure has been determined at near-atomic resolution (Wishner, B.C., Ward, K.B. Lattmen, E.E. & Lowve, W.E. (1975) J. Mol. Biol. 98, 179-194). Double filaments of molecules with an axial repeat of 64 A comprise the basic unit of both the crystal and fiber structures. Each filament of the pair is translated with respect to its neighbor by half a molecular diameter along the fiber axis. The two filaments are held together by contacts made by Val 6beta in the molecules of one strand with hydrophobic side chains of the molecule in the neighboring strand. This interaction is probably the cause of the aggregation of filaments into fibers that leads to the sickling of erythrocytes.

Crystallography↗