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DNA viruses in urine after renal transplantation.

Approximately 2 500 specimens from 96 renal transplant recipients were examined for virus particles. Electron microscopy of negatively stained preparations showed that only 3 virus groups were present, namely polyomavirus, adenovirus and herpesvirus. No RNA viruses or oncogenic RNA viruses (retraviridae) were detected. Over a 5-year period polyomavirus was excreted by 37,5% of patients. Both herpesvirus and adenovirus were excreted by approximately 11% of the patients. Although trace quantities of other viruses may have been missed, the absence of RNA virus suggests that immunosuppressive treatment activates these DNA viruses. The failure to detect RNA viruses suggests that they are absent or may require different means of activation.

Adenoviridae↗

Production of dissolved DNA, RNA, and protein by microbial populations in a Florida reservoir.

Production of dissolved macromolecules by ambient autotrophic and heterotrophic microbial populations was measured in a eutrophic Florida reservoir by in situ labeling with various radioactive substrates. When [3H]thymidine was used as the precursor, production of labeled dissolved DNA, RNA, and protein was observed. The rate of production of labeled dissolved macromolecules was 3.1% the rate of cellular incorporation of [3H]thymidine, and the production of dissolved DNA represented 2.3% the rate of cellular DNA incorporation. Microautotrophic populations labeled with NaH[14C]CO3 produced dissolved RNA and protein at rates of 0.24 and 0.11 micrograms of C/liter per h, respectively, or 1.8% the total rate of carbon fixation, with no measurable dissolved DNA production. In an attempt to specifically label phytoplankton DNA, samples were incubated with [3H]adenine or 32Pi in the presence and absence of the photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Although DCMU inhibited 14C fixation by approximately 99%, this antimetabolite had only a slight effect on [3H]adenine incorporation and no effect on 32P incorporation into cellular macromolecules. Significant amounts of dissolved DNA were produced in both [3H]adenine and 32Pi incubations, but again DCMU had no effect on the production rates. These results indicate that actively growing populations of both phytoplankton and bacterioplankton produced dissolved RNA and protein, while only active bacterioplankton produced measurable quantities of dissolved DNA. Dead or senescent phytoplankton may have produced dissolved DNA, but would not be measured in the relatively short incubations used. These findings also indicate that [3H]adenine and 32Pi primarily labeled heterotrophic bacterioplankton and not phytoplankton in this environment.

Bacterial Proteins↗

Isolation of total RNA from dermatophytes.

We report a method for the preparation of total RNA from the anthropophilic dermatophyte Trichophyton rubrum. To generate large quantities of mycelia, the fungus was grown in liquid culture medium. The harvested mycelial mass was ground to a fine powder in liquid nitrogen and homogenized in guanidine isothiocyanate buffer followed by ultracentrifugation of the obtained suspension through a caesium chloride gradient. Analysis of the prepared RNA showed two prominent ribosomal RNA (rRNA) bands of about 3.36 and 1.82 kb. Northern blot hybridization with a beta-actin cDNA confirmed the high quality of the fungal mRNA. Successful isolation of RNA from two other dermatophyte species, namely Trichophyton mentagrophytes and Microsporum canis, demonstrated the general applicability of the described procedure.

Humans↗

Use of the Lieber-DeCarli liquid feeding regime with specific reference to the effects of ethanol on rat skeletal muscle RNA.

This communication discusses the ways in which parameters of tissue injury in chronic ethanol-fed rats can be presented. These are: concentration (amount per unit wet weight), absolute amount (total quantity per organ or tissue) or relative to body weight (total quantity per unit body weight). Specific reference is made to the amount of RNA in skeletal muscles from rats fed the Lieber-DeCarli liquid diet containing ethanol for 6 weeks. Comparisons were made with data from rats which were pair-fed the same diet in which ethanol was substituted by iso-caloric glucose. Chronic ethanol-feeding had no statistically significant effect on the concentration of skeletal muscle RNA, though the absolute amount was reduced by 20%. When expressed relative to body weight the magnitude of this decline was reduced, to only 10%. Due to the nature of the liquid feeding regime the animals showed variable alterations in body weight. The amount of liquid diet consumed by control and ethanol-fed rats over a 24 hr period can comprise as much as 40% (w/w) of body weight. It is therefore suggested that data expressed relative to body mass may, on occasions, be erroneous. Episodic engorgement with food may also have an influence on other metabolic processes such as the kinetics of protein, fat or carbohydrate metabolism. These issues may have important implications for other studies using the Lieber-DeCarli liquid diet to examine the effects of ethanol on muscle or non-muscle tissues.

Animal Feed↗

In vivo assembly of regularly spaced nucleosomes on mouse beta maj-globin DNA cloned in an SV40 recombinant.

Short-term transformation of HeLa cells with an SV40 recombinant carrying a 7.0-Kb mouse genomic globin DNA was studied. It was found that 48 h after transfection the donor DNA was present in the cell nucleus at high copy episomal numbers with the globin gene in regularly spaced nucleosomal form and transcribed into 9S poly A+ RNA. These mini-chromosomes can be isolated in sufficient quantity to allow further biochemical and electron microscopic studies.

Animals↗

Characterization of a protein that interacts with the rat ribosomal gene promoter and modulates RNA polymerase I transcription.

An RNA polymerase I core promoter binding factor (CPBF) was purified to apparent homogeneity from rat adenocarcinoma ascites cells by chromatographic fractionation on a series of columns including an oligodeoxynucleotide affinity column. The final preparation contained two polypeptides with molecular masses of 44,000 and 39,000 daltons. The binding of the factor to the promoter was demonstrated by Southwestern blotting, UV cross-linking and electrophoretic mobility shift assay. The specificity of its binding to the core promoter was confirmed by competitive electrophoretic mobility shift assay using several unlabeled oligo probes in the assay. The addition of increasing amounts of purified CPBF to the in vitro transcription reaction that contains a limiting quantity of the factor resulted in dramatic stimulation of RNA polymerase I (pol I) transcription of rat ribosomal RNA gene. The transcription stimulatory activity associated with the purified CPBF fractions co-purified with the core promoter binding activity in an electrophoretic mobility shift assay. Finally, in a reconstitution transcription system which is devoid of the factor and is incapable of ribosomal gene transcription, purified CPBF could trans-activate the pol I promoter. These data indicate that CPBF is a novel pol I promoter binding factor required for ribosomal gene transcription.

Adenocarcinoma↗

RNA structure analysis assisted by capillary electrophoresis.

Although most capillary electrophoresis (CE) applications in the nucleic acid field performed so far address DNA analysis, various RNA assays by CE have also been done. Both natural and synthetic RNAs have been examined to evaluate their quantities, sizes and interactions. In this report, we show a novel application of CE in RNA research for the analysis of RNA stable conformers. First, we present a successful adaptation of two different enzymatic methods for the 3'-end labeling of RNAs with commercially available fluorescent probes. Then, we show the high performance of CE with laser-induced fluorescence detection (CE-LIF) assisting the structural studies of transcripts. Using the example of regulatory elements present in the breast cancer gene transcript BRCA1, we demonstrate-by direct comparisons-the advantages of CE-LIF over the traditional slab-gel electrophoresis. These include a better and more reproducible separation of conformers, shorter analysis time and higher detection sensitivity.

BRCA1 Protein↗

[Effect of sodium salicylate on the "in vitro" development of RNA viruses (author's transl)].

Sodium salicylate 10(-3) M is able to limit the number of plaques induced by RNA viruses on monkey kidney cell cultures (Cercopithecus aethiops and Macaccus rhesus). However, the inhibition rate changes with the virus type or even the strain used. Poliovirus 2, Coxsackie B3, echovirus and reovirus 1 were the most susceptible to the inhibitory effect of the drug. Latent infection caused by SV5 decreases the antiviral activity of salicylate. The stages of the poliovirus type 2 growth affected by sodium salicylate, were studied. The drug has no direct activity on the infectivity of the virus. It decreases adsorption and penetration. In spite of heavy virus concentration (10(-5,5) to 10(-7)) ID/ml) the eclipse phase is delayed about 3 hours. After 6 hours, viral maturation proceeds and reaches the same level as the controls, and virus quantities recovered are equivalent after 12 hours. Viral infectious RNA fails to induce plaques on salicylate treated cultures. The drug seems to act during the eclipse phase.

Adenoviruses, Simian↗

Globin-chain synthesis in Hb H disease: the activity of red cell precursors and their mRNA.

Globin-chain synthesis was determined in bone marrow and blood of four patients with Hb H disease and in a cell-free system supplemented with poly(A)-rich RNA from the patients. The relative synthesis of alpha-globin ranged between 0.36 and 0.49 in erythroid precursors and between 0.09 and 0.28 in reticulocytes. The relative quantity of biologically active alpha-globin mRNA in poly(A)-rich RNA from bone marrow and blood of these patients ranged between 0.09 and 0.21. The findings suggest the operation, within alpha-thalassemic bone marrow cells, of a translational control mechanism and/or the instability of alpha-globin mRNA.

Bone Marrow↗

Polynucleotide immune complexes in serum and glomeruli of patients with systemic lupus erythematosus.

Several types of antipolynucleotide antibodies were eluted by acid buffer or deoxyribonuclease treatment of glomeruli obtained from nine kidneys from patients with systemic lupus erythematosus (SLE). Anti-SDNA antibodies were found concentrated over serum levels in eight eluates, anti-NDNA in six eluates and anti-RNA Pr in four eluates; anti-DSRNA antibodies were not demonstrable in any eluate tested. Deoxyribonuclease treatment eluted a high incidence and greater quantity of anti-NDNA and anti-SDNA antibody, whereas anti-RNA Pr antibody was mainly eluted by acid buffer. Simultaneous studies of antibody and antigen in serial serum specimens and in glomeruli suggested that complexes of SDNA antibody or antigen excess were frequently deposited in SLE kidneys, in addition to complexes containing anti-NDNA and anti-RNA Pr. It was observed that studies of antibody titers alone were inadequate for predicting the types of complexes deposited in the kidney. Either antigen excess could obscure detection of humoral antibody or extremely high titers of antibody as observed for RNA Pr are not conducive to the formation of kidney localizing immune complexes in the absence of antigen. Immunofluorescence studies demonstrated the presence of SDNA antigen in most cases from which anti-SDNA antibody was eluted providing direct evidence for the presence of SDNA-anti-SDNA complexes in renal glomeruli. A study of complement components indicated that Clq was absent from cases in which little or no SDNA was deposited in renal glomeruli; although all nephritic kidneys demonstrated C3 deposits. Several hypotheses accounting for this observation are discussed, including the probable utilization of the alternate pathway by certain types of complexes and a direct reaction between C1q and circulating or tissue-bound NDNA or SDNA.

Animals↗

A large nucleoprotein fragment of the 50-S ribosomal subunit of Escherichia coli.

A large nucleoprotein fragment was isolated from a nuclease digest of Escherichia coli 50-S ribosomes and purified to gel electrophoretic homogeneity. Conditions were employed under which the fragmentation pattern was reproducible and the various fragment fractions were stable and maintained their sedimentation and electrophoretic properties throughout the several preparative and analytical procedures used. Fractions that appeared homogeneous in sucrose gradient centrifugation were found to be heterogeneous by gel electrophoresis. The large fragment was purified to homogeneity by preparative gel electrophoresis. It contained 21 proteins, the 5-S RNA, and two large oligonucleotides which together total about two thirds the molecular weight of the 23-S RNA. Because it can be prepared reproducibly in large quantities and because of its size and stability, the fragment appears suitable for functional and structural studies and as the starting material for further fractionation. An important contributing factor to the observed stability and reproducibility was the maintenance of an unchanging ionic environment. A single buffer was employed throughout all the procedures, and the fragments produced by nuclease digestion were dissociated from each other by heat rather than by changing the medium.

Enzymes, Immobilized↗

Cyclic AMP regulation of pro-vasoactive intestinal polypeptide/PHM-27 synthesis in human neuroblastoma cells.

The mechanism of N6,O2'-dibutyryl adenosine 3':5'-monophosphate (Bt2cAMP) induction of pro-vasoactive intestinal polypeptide (VIP)/PHM-27 biosynthesis was investigated in human neuroblastoma cells in culture. When neuroblastoma cells were grown for 48 h in the presence of 1 mM Bt2cAMP, the synthesis of pro-VIP/PHM-27 was stimulated 11-fold. The amount of prepro-VIP/PHM-27 mRNA determined both by hybridization with cloned prepro-VIP/PHM-27 cDNA and a reticulocyte cell-free translation assay was also increased 11-fold in the Bt2cAMP-induced cells. Transcription of prepro-VIP/PHM-27 mRNA in isolated nuclei was observed in induced cells, but not in uninduced cells. Blot hybridization with prepro-VIP/PHM-27 cDNA of total nuclear RNA isolated from neuroblastoma cells revealed an RNA species corresponding to mature prepro-VIP/PHM-27 mRNA, and the amount of the RNA was markedly increased in the induced cells. The quantity of VIP/PHM-27 gene in the DNA of neuroblastoma cells was analyzed after hydrolysis with a restriction endonuclease, EcoRI. However, VIP/PHM-27 gene was not amplified in the induced cells. These results indicate that Bt2cAMP-induced pro-VIP/PHM-27 synthesis is achieved by enhancing the transcription rate of prepro-VIP/PHM-27 mRNA.

Animals↗

Evolution of host cell RNA into efficient template RNA by Q beta replicase: the origin of RNA in untemplated reactions.

Q beta replicase can replicate a single molecule of certain species of RNA to 10(14) copies in minutes. This replication ability has been used for in vitro studies of molecular evolution and is currently being utilized as a method of amplifying RNAs that contain probe sequences. It has been observed that Q beta replicase can produce replicatable RNA even in the absence of exogenously added template RNA. The origin of this RNA has been ascribed either to contamination with replicatable RNA or to an ability of Q beta replicase to synthesize RNA de novo from the nucleotides present in the reaction. Technologies that employ Q beta replicase require a thorough understanding of the conditions that lead to this so-called spontaneous RNA production. We have created an expression system and purification method with which we produce gram quantities of highly purified Q beta replicase, and we have identified reaction conditions that prevent the amplification of RNA in assays that do not contain added RNA. However, when these reaction conditions are relaxed, spontaneous RNA replication is seen in up to 100% of the assays. To understand the origin of this RNA, we have cloned several spontaneously produced RNAs. Sequence analysis of one of these RNAs shows that it arose by the evolution of Escherichia coli tRNA into a replicatable template and not by de novo synthesis from nucleoside triphosphates in the reaction.

Allolevivirus↗

Binding properties of the human immunodeficiency virus type 1 nucleocapsid protein p7 to a model RNA: elucidation of the structural determinants for function.

HIV-1 nucleocapsid protein (NCp7) is a double zinc-fingered protein that has been traditionally implicated in viral RNA recognition and packaging, in addition to its tight association with genomic RNA and tRNA primer within the virion nucleocapsid. The availability of large quantities of viral or recombinant wild-type NCp7 and mutant p7 has made possible the assignment of the different roles that structural motifs within the protein play during RNA binding. At low ionic strength binding to the homopolymeric fluorescent RNA, poly(epsilonA), is electrostatically driven and four sodium ions are displaced. Arg7 in the flanking N-terminal region, Lys20 and Lys26 in the first zinc finger and one positively charged residue (attributed to Lys41) in the second zinc finger are involved in electrostatic contacts with RNA. The p7 zinc fingers do not function independently but concomitantly. The first zinc finger (both isolated or in the context of the full-length protein) has a more prominent electrostatic interaction than the second one. The second zinc finger dominates the non-electrostatic stabilization of the binding to RNA due to stacking of its Trp residue with nucleic acid bases. Mutations in the highly conserved retroviral Zn-coordinating residues (CCHC) to steroid hormone receptor (CCCC) or transcription factor (CCHH) metal cluster types do not affect RNA binding. In spite of the limited impact in RNA binding affinity in vitro or RNA packaging in vivo that such mutations or structural alterations impart, they impair or abolish virus infectivity. It is likely that such an effect stems from the involvement of NCp7 in crucial steps of the virus life cycle other than RNA binding.

Amino Acid Sequence↗

In vivo analysis of cancerous gene expression by RNA-polymerase chain reaction.

An easy and routine procedure to amplify messenger RNA (mRNA) libraries from a few tissue cells can provide molecular gene expression profiles at high resolution. A novel PCR-like method, the RNA-PCR, was developed to generate high quality and quantity mRNAs from as few as 20 cells (2 pg mRNAs). The principle relies upon the cycling steps of promoter-linked double-stranded cDNA synthesis and promoter-driven transcription to amplify mRNAs up to 250-fold/cycle with good representation of high and low copy mRNAs. The amplified mRNA libraries were shown to possess high fidelity, purity, specificity and reproducibility for in vivo analyses of cancerous gene expression in human prostate cancers.

Base Sequence↗

Keratinocyte growth factor expression by the bovine corpus luteum.

Communication between cells of the corpus luteum (CL) is thought to be necessary for normal luteal function. Keratinocyte growth factor (KGF) is produced by mesenchymally derived cells in numerous tissues and acts on epithelial cells. In bovine follicles, theca cells produce KGF, which can stimulate granulosa cell proliferation. Whether KGF is produced by ovarian cells after luteinization is unknown. Our objective was to determine whether KGF mRNA and protein were present in bovine luteal tissue, and if so, to determine what type(s) of luteal cells contains KGF. CL (n = 3-4/day) were obtained from specific days throughout diestrus. Presence of KGF mRNA in CL was determined using a porcine KGF anti-sense cRNA probe. Northern analyses of luteal tissue poly(A)+ RNA revealed a single transcript (approximately 2.0 kilobases), the quantity of which did not change throughout diestrus. Western analysis revealed an immunoreactive band (28 kDa) in luteal tissues and theca cell homogenates that was absent from granulosa cell homogenates. Immunocytochemistry showed KGF predominantly in theca and small luteal cells. Results indicate that bovine CL produce and contain KGF, which is primarily localized in small luteal cells. Therefore, KGF may participate in paracrine communication within the bovine CL.

Animals↗

Pharmacological and molecular evidence that the contractile response to serotonin in rat stomach fundus is not mediated by activation of the 5-hydroxytryptamine1C receptor.

The receptor mediating contraction in response to serotonin in the rat stomach fundus has not been characterized in light of the currently acceptable serotonergic receptor classification scheme. Several biochemical and pharmacological approaches to a characterization of this receptor have demonstrated nonidentity with the 5-hydroxytryptamine2 (5HT2), 5HT3, 5HT1A, and 5HT1B receptors, as defined by radiolabeled ligand binding studies in brain cortical membranes. Although there have been reports suggesting that the receptor in the rat stomach fundus may be analogous to the 5HT1C receptor, other pharmacological and biochemical studies have not been consistent with this idea. The present study utilized high affinity ligands for the 5HT1C receptor and the recently derived 5HT1C receptor cDNA clone to provide a more definitive approach to the examination of the relationship between the 5HT1C receptor and the serotonergic contractile receptor in the rat stomach fundus. Using three ligands with high affinity at the 5HT1C receptor, LY53857, ritanserin, and SCH23390, the contractile response to serotonin was inhibited by all three ligands. However, inhibition did not appear competitive nor was the inhibitory potency of these ligands consistent with their affinity at 5HT1C binding sites in brain cortical membranes. We further showed that SCH23390, unlike LY53857 and ritanserin, was also a partial agonist, producing a maximal contraction that was approximately 50% of the maximal response to serotonin in the rat stomach fundus. Thus, the use of these ligands did not support the contention that the receptor mediating serotonin-induced contractions in the rat stomach is identical to the 5HT1C receptor. In more definitive studies using a 5HT1C receptor cDNA probe, we were unable to detect hybridization of the probe with any mRNA species from the rat stomach fundus, whereas the 5HT1C receptor cDNA probe did hybridize to the 5HT1C receptor mRNA in rat brain. Because the cathepsin-D cDNA probe hybridized equally in rat brain and stomach fundus, ensuring the integrity of the RNA preparation from both tissues, the absence of measurable quantities of the 5HT1C receptor mRNA in the rat stomach was probe specific and not an artifact. Furthermore, primers specific for the rat 5HT1C receptor sequence did not detect significant levels of receptor mRNA in rat fundus, although the target sequence was amplified a minimum of 10(5)-fold in a polymerase chain reaction. These studies do not support the contention that the receptor mediating contractile responses to serotonin in the rat stomach fundus is identical to the 5HT1C receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗