Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RNA fractions were prepared by sucrose density gradient centrifugation from hot-cold phenol, RNA-rich extracts of lymphoid tissues from strain 2 guinea pigs hyperimmunized to line 1 or line 10 tumors. Each RNA fraction was assessed for its ability to convert nonsensitized strain 2 peritoneal exudate cells to a state of specific sensitivity for line 1- or line 10-solubilized tumor antigens. An RNA fraction residing between the 4 S and 18 S peaks, designated as Fraction "B", transferred line 10 or line 1 sensitivity in 12 experiments. Twelve additional RNA extracts containing 2 subfractions prepared from RNA fraction B, designated as B1 and B2, also transferred line 1 or line 10 sensitivity in 14 experiments. Except for 3 experiments where the 4 S or 18 S material transferred tumor-specific sensitivity, RNA fractions corresponding to approximately 4 S, 18 S, 22 S, and 28 S were unable to transfer tumor-specific sensitivity to nonsensitized peritoneal exudate cells. Treatment of fraction B with RNase results in complete loss of ability to transfer immunobiological activity.
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PMID:Isolation and localization of RNA fractions able to transfer tumor-specific delayed hypersensitivity in vitro. 18 27

After continuous 3H-TdR infusion in vivo or incubation with 3H-TdR in vitro human blood lymphocytes were examined by light-microscopic and electron-microscopic autoradiography. Using relatively long autoradiographic exposure times (50--300 days) not only nuclear but also cytoplasmic labelling was visualized, the cytoplasmic label being present in up to 96% of the cells. The cytoplasmic label was predominantly associated with the mitochondria and was removed from the cells nearly completely by treatment with DNase but not with RNase or cold perchloric acid. It is concluded that this cytoplasmic label mainly represents 3H-TdR incorporated into mitochondrial DNA which is continuously renewed in an average turnover time of 14 days or less. This value is compatible with a turnover time of 11 days for mitochondrial DNA in mammalian cells reported in the literature.
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PMID:Labelling of human resting lymphocytes by continuous infusion of [3H]thymidine. I. Characterization of cytoplasmic label. 72 7

Protoplasts of Actinomyces hygroscopicus were obtained in a hypertonic medium containing 10.3% sucrose. Lysozyme was employed as a lysing agent at a concentration of 1 mg/ml. The cells were subjected to lysis during 3-4 hours at 37 degree C, the concentration of biomass being 0.05 g of dry mycelium per 1 ml of hypertonic solution. Production of protoplasts was controlled by phase-contrast microscopy; the amount of the protoplast was determined by optical density at lambda=530 nm. The highest amount of the protoplasts was obtained during growth of the culture on a medium containing 0.5% glycine. The membrane fraction was isolated after lysis of the protoplasts in a hypotonic medium, treatment with DNase and RNase, and centrifugation at 22,000 g in the cold. Production of the membranes was controlled by electron microscopy. The yield of the membranes was 17-19% of the dry mycelium weight. They contained about 35% of lipids, 50% of protein, and 5% of RNA.
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PMID:[Production of protoplasts and membranes in Actinomyces hygroscopus]. 100 73

A primary transcript from the chloroplast rpl32 gene was labelled at its 5' end using a capping enzyme and [alpha-32P]GTP followed by hybridization to a cold RNA probe. A RNase protection assay gave a clear protected band and its initiation site of transcription could thus be estimated, which had not been possible by using DNA probes. The combination of in vitro capping and RNase protection is an excellent method for mapping transcription initiation sites on the chloroplast genome and shows a high improvement relative to the DNA-employing strategies.
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PMID:Combination of in vitro capping and ribonuclease protection improves the detection of transcription start sites in chloroplasts. 162 81

The X-ray structures of two complexes of bovine ribonuclease-A produced by soaking pre-grown crystals in solutions of the inhibitors cytidylyl-2',5'-guanosine (2',5' CpG) and deoxycytidylyl-3',5'-guanosine (3',5'dCpdG) have been determined at 1.5 A resolution and refined by restrained least squares to R = 21.0% for 17,855 reflections, and R = 19.1% for 16,347 reflections, respectively. Binding of the substrate analogs to the protein has taken place in a completely unexpected and previously unreported manner. In each case the guanine base occupies the well characterized B1 pyrimidine binding site adjacent to Thr-45 (described by Richards, F.M., Wyckoff, H.W., Carlson, W.D., Allewell, N.M., Lee, B. and Mitsui, Y. (1971) Cold Spring Harbor Symp. Quant. Biol. 36, 35-54, and others including Palmer, R.A., Moss, D.S., Haneef, I. and Borkakoti, N. (1984) Biochim. Biophys. Acta 785, 81-88) having entered through a secondary channel external to the active site itself. We designate this reversed non-productive mode as retro-binding. In this mode of binding the SO4(2-) anion bound in the active site of the native protein crystals (Borkakoti, N., Moss, D.S. and Palmer, R.A. (1982) Acta Crystallogr. B38 2210-2217) has not been displaced by the phosphate of the inhibitor molecule as originally anticipated and observed in other studies. Instead the CMP or dCMP moiety of the inhibitor molecule is held loosely in a channel running towards the surface of the protein molecule and is thus completely external to the active site. Consequently, although it has been possible to model them, no attempt has been made to refine either the disordered cytosine in the CpG complex or the deoxycytosine in the dCpdG complex. The traditional B2 purine binding site of RNase (Richards et al., 1971) is unoccupied by the soaked inhibitors. Important changes that have taken place in the protein structure include: stabilization of both Lys-41 and Gln-11 via H-bonding to SO4(2-); stabilization of His-119 in the A conformation (Borkakoti, N., Moss, D.S. and Palmer, R.A. (1982) Acta Crystallogr. B38 2210-2217); and stabilization of SO4(2-) by H-bonds formed with the retro-bound guanine base. Binding of the inhibitors and stabilization of the active site is accompanied by displacement and redistribution of solvent molecules.
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PMID:Novel non-productively bound ribonuclease inhibitor complexes--high resolution X-ray refinement studies on the binding of RNase-A to cytidylyl-2',5'-guanosine (2',5'CpG) and deoxycytidylyl-3',5'-guanosine (3',5'dCpdG). 176 78

Seeking to optimize the immunocytochemical assay of P-glycoprotein, a 170-kilodalton (P-170) molecule associated with multidrug resistance, we experimented with a variety of antibodies (JSB-1, C219, and MRK-16), fixation conditions, and titers using both human myeloma cell lines and clinical myeloma specimens. Under optimized conditions, using all three antibodies and the cell lines as standards and controls, the ICC method proved sensitive, specific, reliable, rapid, and within the realm of everyday hospital laboratory expertise. The 3 anti-P-glycoprotein antibodies revealed different reactivities with P-170. Both C219 and JSB1 were optimized by fixation in cold acetone. With MRK-16 optimal results were obtained on unfixed or formalin fixed specimens. Under optimal fixation and titering conditions, low level (DOX 4) detection was possible. Given that the three antibodies differ in reactivity and recognize different P-170 epitopes, it follows that using the antibodies in a small panel is a useful strategy in increasing the likelihood of detecting true P-glycoprotein expression by the immunocytochemical method. In dilution experiments, the immunocytochemical method was as sensitive as RNase protection assay and more sensitive than Western blot detection. Immunocytochemistry coupled to computer-assisted single-cell densitometry, showed a strong correlation (R = 0.98) between cellular P-170 density and in vitro resistance to doxorubicin. Multidrug-resistant specific probes for RNA expression and Western blot assays confirmed the specificity of P-170 expression in both cell lines and clinical samples. Thus, a small panel of antibodies, under optimized immunocytochemical conditions, appears to have potential as a rapid, sensitive, clinically useful assay for multidrug resistance in myeloma.
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PMID:Optimization of immunocytochemical P-glycoprotein assessment in multidrug-resistant plasma cell myeloma using three antibodies. 197 62

Through the use of the immunoelectron microscopical technique, uncoupling protein (UCP) was analyzed in the brown adipocytes of room temperature- and cold-acclimated rats, in rat brown adipocytes developed in vitro, and in the brown adipocytes of mice, hamsters, and hedgehogs. Using rat anti-UCP-antibody, it is shown that UCP is located in the cristae of brown adipocytes mitochondria (UC-mitochondria) of all analyzed species, whereas mitochondria of nonadipose cells, i.e., C-mitochondria of endothelium, fibrocytes, smooth muscle cells, Schwann cells, axons of neural cells, and white blood cells, do not contain UCP. Cold stress in rats exposed to temperatures of +4 and -20 degrees C caused the amount of UCP per 1 micron 2 of mitochondria to more than double compared with room temperature-acclimated rats. This increase was especially dramatic on the outer mitochondrial membrane: fourfold more UCP molecules compared to the control rats. The ground cytoplasm of adipocytes showed very intensive labeling with RNase-gold complex, indicating that cytoplasm was an active site for protein synthesis, while the absence of UCP-labeling in ground cytoplasm was interpreted to mean that ground cytoplasm did not serve as a site for UCP synthesis. On the other hand, the protrusions of the outer mitochondrial membrane covered with ribosomes, clusters of UCP molecules, and clusters of RNase-gold particles supported the idea that UCP was one of the mitochondrial proteins synthesized on the ribosomes which were in contact with the outer mitochondrial membrane. After being synthesized there, UCP, which could be either extruded into intermembranous space or directed by lateral movement to intermembranous contact sites, was incorporated into inner mitochondrial membrane. Thus, UCP is imported using the so-called "cotranslational transport system."
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PMID:Immunoelectron microscopical studies on synthesis and localization of uncoupling protein in brown adipocytes: evidence for cotranslational transport of uncoupling protein into mitochondria. 212 16

Mesenchymal cells isolated from the papilla of embryonic tooth germs of the mouse were cultured in a complex medium for five to six days. Liquid nitrogen lysates, prepared from these cells, incorporated nucleoside monophosphates into a cold acid-insoluble product. The product was sensitive to RNase and no product was formed if the lysate was pretreated with DNase. The reaction was sensitive to EDTA and, in its presence, optimum activity was obtained with 2 mM MgCl2. On sucrose gradients, the reaction product was distributed between two broad peaks; one centered about 18S and the other above 28S. The RNA polymerase inhibitor alpha-amanitin inhibited approximately 50% of the activity at a concentration of 10 microgram/ml.
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PMID:Transcriptional activity in lysates of cultured mesenchymal cells from embryonic tooth germs. 615 75

A processing endoribonuclease was isolated from the cytoplasm of chick embryos. The enzyme was easily obtained using an RNA extraction procedure based on a mild deproteinization with Sarkosyl and cold phenol/chloroform. This technique assured the recovery of several proteins and the endoribonuclease in association with the RNA. It was demonstrated that this endoribonuclease was capable of promoting, in vitro, a precise processing of naked 45-S ribosomal RNA precursor to molecules resembling the intermediates as well as the 28-S and 18-S cytoplasmic RNAs found in vivo. The presence of magnesium ions was required for the correct processing function of the enzyme. In addition, under the same conditions, the mature ribosomal RNA substrates were degraded at a slower rate by this RNA-associated RNase. It was possible to fractionate the enzymatic preparation into two different populations by means of a sucrose gradient: one associated and the other partially free of an RNA component. The effect of the intrinsic RNA associated with the endoribonuclease on the enzymatic activity was tested by analyzing both the enzymatic populations and the total enzymatic preparation treated with pronase or with immobilized pancreatic RNase. In all cases in which the RNA component was present, the enzyme showed processing activity. On the other hand, when the RNA component was absent or at least partially degraded the enzyme proved to be more active in processing precursor molecules and in promoting extensive degradation of mature RNA species. Although the presence of RNA in association with the enzyme was demonstrated, its role in the regulation of the enzymatic activity is yet not clear.
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PMID:Processing of naked 45-S ribosomal RNA precursor in vitro by an RNA-associated endoribonuclease. 616 85

Ribonucleic acid extracts were isolated by cold phenol extraction procedure from lymphoid organs of mice immunized with allogeneic skin grafts. Cultivation of lymphocytes from normal mice with these RNA extracts in vitro led to the induction of specific immunological reactivity which was determined by microcytotoxicity assay. Pretreatment of the RNA extracts with DNase enhanced their ability to induce cytotoxicity, while pronase had no effect, and RNase completely inhibited the ability of extracts to sensitize lymphocytes. The results show that specific cell-mediated cytotoxicity can be induced in vitro in lymphocytes from normal animals by a transfer of "immune" RNA.
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PMID:Induction of specific cell-mediated cytoxicity in vitro by means of RNA isolated from allografted mice. 617 68


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