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At least 1,801 records · Page 100Linked to original sources
PubMed1993

Basic fibroblast growth factor and its receptor messenger ribonucleic acids are expressed in human ovarian epithelial neoplasms.

OBJECTIVE: Our purpose was to determine whether basic fibroblast growth factor is present in, and synthesized by, human ovarian epithelial neoplasms and to evaluate the expression of gene for the basic fibroblast growth factor receptor. STUDY DESIGN: The synthesis of basic fibroblast growth factor and its receptor was investigated in seven primary human ovarian epithelial neoplasms. Neoplastic tissues were homogenized and the cytoplasmic extracts purified by heparin-sepharose chromatography with a linear salt gradient of 0.6 to 3 mol/L sodium chloride in Tris-hydrochloric acid. The in situ synthesis of basic fibroblast growth factor and its receptor was demonstrated by polymerase chain reaction. Total ribonucleic acid was reverse transcribed and then amplified with two oligonucleotide primers specific for the bovine and human basic fibroblast growth factor gene and its human receptor gene. RESULTS: As assessed by both bioassay and radioimmunoassay a peak of basic fibroblast growth factor-like activity was present in all tumors in the chromatographic fractions eluted with 3 mol/L sodium chloride. The mitogenic effect on bovine adrenocortical endothelial cell proliferation varied from 35% to 153% above control cultures. Levels of basic fibroblast growth factor-like immunoreactivity were between 4 and 33 ng/ml. Qualitatively similar results were obtained after purifying the cytoplasmic extract of dispersed human ovarian tumor cells. The mitogenic effect was completely abolished by a specific neutralizing anti-basic fibroblast growth factor antibody. Single major deoxyribonucleic acid bands of the expected size (354 and 661 bp) were detected in all tumors studied. The identify of this material with the human basic fibroblast growth factor sequence was confirmed by restriction enzyme analysis. CONCLUSION: These data demonstrate that both basic fibroblast growth factor and its receptor are present in and synthesized by human ovarian tumor cells. Thus basic fibroblast growth factor might stimulate their abnormal proliferation through an autocrine mechanism.

Carcinoma↗
PubMed1971

Ribonucleic acid polymerase activity in Sendai virions and nucleocapsid.

After dissociation of purified Sendai virus with the neutral detergent Nonidet P-40 and 2-mercaptoethanol, it catalyzed the incorporation of ribonucleoside triphosphates into an acid-insoluble product. The enzyme activity was associated with viral nucleocapsid as well as whole virions. The reaction product was ribonucleic acid (RNA) which annealed specifically with virion RNA. Sedimentation of the (3)H-RNA reaction product revealed two components, a 45S component with properties of double-stranded RNA and 4 to 6S component which appeared to be mostly single-stranded RNA.

Adenosine Triphosphate↗
PubMed1975

Effect of narcotic drugs on ribonucleic acid and nucleotide metabolism in mouse brain.

Mice either were administered 10, 30 or 100 mg/kg of morphine sulfate acutely or were chronically implanted with pellets containing morphine, naloxone or pentazocine. They were then injected intraperitoneally or intracerebroventricularly with [5-3H] uridine or [5-3H] orotic acid either 30 minutes, 24 hours of 48 hours before sacrifice. The incorporation of the 3H into brain total homogenate, ribonucleic acid (RNA) and uridine nucleotides was measured. The RNA content of brain and liver was also assayed. When [3H] uridine was injected. i.p. 30 minutes before sacrifice, acute injection of 30 or 100 mg/kg of morphine sulfate or chronic implantation of morphine pellets decreased the incorporation of the [3H] uridine into brain RNA. However, neither the acute administration of 10 mg/kg of morphine sulfate, nor the chronic administration of naloxone or pentazocine, altered the amount of radioactivity incorporated into RNA. Chronic morphine treatment decreased the incorporation of 3H into uridine nucleotides and nucleotide sugars due partially to increased catabolism of the [3H] uridine. The brain and liver RNA concentration was unchanged by chronic morphine administration. Thus, chronic morphine treatment alters the metabolism of uridine nucleotides but does not appear to alter the net synthesis of the total brain RNA.

Animals↗
PubMed1998

Localization of leukemia inhibitory factor and interleukin-6 messenger ribonucleic acids in regenerating rat skeletal muscle.

In the present study, we characterized both temporal and spatial expression patterns of leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) messenger ribonucleic acids (mRNAs) in injured skeletal muscle using in situ hybridization. LIF and IL-6 mRNAs were expressed in mononucleated cells and damaged muscle cells. Further, signals for LIF mRNA were also detected in Schwann cell-like cells of intramuscular nerves. These results suggest that the earliest events involved in the repair of injured muscles and nerves may be triggered by these cytokines.

Animals↗
PubMed1980

Translation of chick aortic elastin messenger ribonucleic acid. Comparison to elastin synthesis in chick aorta organ culture.

Studies were undertaken to define the molecular size of the elastin primary gene product. Translation of chick aortic messenger ribonucleic acid (mRNA) in an mRNA-dependent reticulocyte lysate resulted in the synthesis of two major proteins of 70 000 and 73 000 molecular weights. Both proteins were shown to be soluble forms of elastin by isotope incorporation, immunoprecipitation, collagenase and cyanogen bromide sensitivity, and two-dimensional gel electrophoresis. The 70 000-dalton protein behaves similarly to authentic tropoeleastin in sodium dodecyl sulfate gel electrophoresis. There was no evidence for a high molecular weight form of soluble elastin, although procollagen chains were indirectly identified among the aortic mRNA-directed translation products. The same molecular size proteins were also seen in organ cultures of chick embryonic aortas labeled with [3H]valine. However, the 73 000-dalton protein was not extractable in a neutral salt buffer but was found only if the aortas were extracted with urea in the presence of reducing and alkylating reagents. The results from these studies suggest that elastin is first synthesized as two distinct polypeptide chains which differ slightly in size and overall charge. The possibility that these two proteins may associate posttranslationally to form a dimer prior to secretion is postulated to explain the existence of a putative proelastin molecule seen in other systems.

Animals↗
PubMed1990

Relationship between somatostatin and growth hormone messenger ribonucleic acid in human pituitary adenomas: an in-situ hybridization histochemistry study.

We have used quantitative in-situ hybridization histochemistry to assess the somatostatin (SRIH) and GH messenger ribonucleic acid (mRNA) content of 81 pituitary adenomas. SRIH mRNA was found in the absence of GH mRNA in only one tumour and in the five cases in which GH and SRIH mRNA were both present, SRIH mRNA prevalence was approximately two orders of magnitude less than GH mRNA. However, no direct correlation between GH mRNA, SRIH mRNA and circulating GH levels was evident at the time of surgery. In contrast, there was no detectable SRIH mRNA probe binding to a thyrotroph adenoma, a gonadotroph adenoma, 29 endocrinologically inactive pituitary adenomas, nine lactotroph adenomas, two first trimester fetal and two normal adult pituitary glands obtained 24 and 36 h post-mortem. These findings corroborate previous reports of SRIH release from somatotroph adenomas in vitro and suggest that paracrine or autocrine mechanisms linking SRIH and GH mRNA operate within normal pituitary tissue. As somatotroph adenomas are thought to be predominantly clonal in origin, the data further suggest that GH and SRIH are synthesized in the same or closely related cells.

Adenoma↗
PubMed1970

Thermally induced intracellular alteration of ribosomal ribonucleic acid.

Heating at 55 C causes the intracellular degradation of ribosomes of Staphylococcus aureus MF-31. The 30S subunit of heated cells appears to be selectively attacked. Analysis of ribonucleic acid (RNA) showed that 16S RNA was destroyed and that the secondary structure of 23S RNA was altered.

Acetates↗
PubMed1973

Effect of alanine, leucine and fructose on lysyl-transfer ribonucleic acid ligase activity in a mutant of Escherichia coli K-12.

A mutant of Escherichia coli K-12 was examined which has growth medium-dependent lysyl-transfer ribonucleic acid (tRNA) ligase activity. In minimal medium or 0.5% yeast extract, the activity of the enzyme in the mutant strain was 5 to 10% of wild type. However, when the mutant was grown in a highly enriched medium, such as AC broth (Difco), the activity of the mutant ligase increased 10- to 20-fold. We found that the supplementation of 0.5% yeast extract by l-alanine plus d-fructose replaces the need for the highly enriched medium. Fructose plus l-leucine and fructose plus l-alpha-amino-n-butyric acid were also stimulatory, but not as effective as fructose and alanine. With minimal medium, a combination of carbohydrate (fructose or glucose) plus alanine and leucine was required to replace the enriched medium. The most effective combination was fructose, glucose, alanine, and leucine. Lysyl-tRNA ligase was stimulated 1.5 to 2-fold in the wild-type strain or Hfr H (Hayes) by fructose plus alanine when these strains were cultured in 0.5% yeast extract. Experiments employing the combined technique of density labeling with D(2)O and isopycnic centrifugation in cesium chloride indicated that the increased activity of lysyl-tRNA ligase observed in AC broth or in the presence of fructose, glucose, alanine, and leucine is due to the synthesis of new enzyme.

Alanine↗
PubMed1973

Isolation of a specialized lambda transducing bacteriophage carrying the beta subunit gene for Escherichia coli ribonucleic acid polymerase.

A heat-inducible lysis-defective lambda prophage has been integrated directly into the E. coli chromosome at a site (bfe) very closely linked to the ribonucleic acid polymerase mutation rif(d), a dominant rifampin resistance allele. This unusual lysogen has facilitated the isolation of specialized transducing phages conferring rifampin resistance to sensitive cells, and carrying at least the beta subunit gene of RNA polymerase in intact form.

Alleles↗
PubMed1979

Comparative surfact structure of 16S ribosomal ribonucleic acid of 30S ribosomes of procaryotic cells.

Ribonuclease T(1) treatment of 30S ribosomes of Escherichia coli converts a large region at the 3' OH end of 16S ribosomal ribonucleic acid (rRNA) to low-molecular-weight RNA. The final 25 nucleotides at the 3' terminus of the molecule emerge relatively intact, whereas most of the region "upstream," for about 150 nucleotides, is converted to oligonucleotides. Identical enzyme treatment generates a fragment of about 60 nucleotides from the middle of 16S rRNA (section D'). To determine whether there are similar sequences in other bacteria, which occupy similar accessible surface locations, we treated 30S ribosomes from Azotobacter vinelandii and Bacillus stearothermophilus with RNase T(1). In each case, a fragment of RNA about 25 nucleotides in length containing the 3' OH end of 16S rRNA and a fragment of about 60 nucleotides in length similar, but not identical, in oligonucleotide composition to section D' of E. coli 16S rRNA were obtained from nuclease-treated 30S ribosomes. These data indicate that, although the primary structure at the 3' end and the middle (section D') of the various 16S rRNA's is not completely conserved, their respective conformations are conserved. A number of identical oligonucleotides were found in the low-molecular-weight fraction obtained from RNase T(1)-treated E. coli, A. vinelandii, and B. stearothermophilus 30S ribosomes. These results show that identical RNase T(1)-sensitive sequences are present in all three bacteria. Hydrolysis of these regions leads to the production of the fragments 25 and 60 nucleotides in length.

Azotobacter↗
PubMed1968

Cellular origin of a mouse leukemia viral ribonucleic acid.

Mouse erythroblastosis virus, a member of the mouse leukemia virus group, was obtained from chronically infected C(3)H mouse embryo cells and purified on sucrose gradients. The ribonucleic acid (RNA) extracted from ribonuclease-treated virus consisted of a rapidly sedimenting (72S) species and a more slowly sedimenting component (4 to 30S). The 72S RNA did not contain base sequences homologous to deoxyribonucleic acid (DNA) from infected cells as determined by hybridization studies. In contrast, the slowly sedimenting RNA enclosed within the virus had base sequences homologous to DNA from infected and uninfected C(3)H mouse embryo cells.

Animals↗
PubMed1978

A proposed nucleotide sequence for the 5S ribosomal ribonucleic acid of rainbow trout (Salmo gairdneri).

Rainbow trout cell cultures have been exposed to 32P-labelled inorganic phosphate and the labelled RNA has been isolated. The 5S ribosomal ribonucleic acid (5S rRNA) was purified by polyacrylamide gel electrophoresis, then digested with RNase T1 or pancreatic RNase. The products of complete digestion were separated and their sequences determined. These analyses have allowed a sequence to be proposed which differs in eight positions from that of mammalian 5S rRNAs.

Animals↗
PubMed2003

[Expression of leptin and long form of leptin receptors messenger ribonucleic acid and protein in endometrium of patients with polycystic ovary syndrome].

OBJECTIVE: To study the expression of leptin and long form of leptin receptors (Ob-R(L)) messenger ribonucleic acid (mRNA) and protein in endometrium during mid-luteal phase of patients with polycystic ovary syndrome (PCOS). METHODS: The expression of leptin and Ob-R(L) mRNA in endometrium during mid-luteal phase from 15 normal controls and 14 PCOS related anovulatory patients who underwent ovulation induction therapy were studied by in situ hybridization, and levels of leptin and Ob-R(L) protein were investigated by immunohistochemical methods. RESULTS: The expression of Ob-R(L) mRNA and protein in endometrial glands of most patients with PCOS were weak or moderate positive, whereas the levels of Ob-R(L) mRNA and protein were moderate or strong positive in those of the controls, there was significant difference between the two groups; leptin mRNA and protein expression in endometrium of patients with PCOS and controls were not significantly different between the groups. CONCLUSION: The expression of Ob-R(L) decreased in endometrium of mid-luteal phase in patients with PCOS during induced ovulation, which may be related to low pregnancy rate of patients with PCOS.

Adult↗
PubMed1996

Transforming growth factor-beta 1 and -beta 2 induce inhibin and activin beta B-subunit messenger ribonucleic acid levels in cultured human granulosa-luteal cells.

OBJECTIVE: To examine the effect of transforming growth factor-beta (TGF-beta) on inhibin and activin subunit messenger ribonucleic acids. DESIGN: Human granulosa-luteal cell culture model. SETTING: Granulosa cells were obtained from women undergoing an IVF program in a private IVF clinic. PATIENTS: Regularly menstruating women undergoing oocyte retrieval for IVF because of either tubal obstruction or infertility of the spouse. INTERVENTIONS: For each experiment, cells of two to four patients were pooled, enzymatically dispersed, separated from red blood cells by centrifugation through Ficoll-Paque and cultured in vitro in the presence of TGF-beta 1 or TGF-beta 2 and/or hCG whereafter cellular RNA was extracted for Northern or dot blot filter hybridization with inhibin alpha-, beta A, and beta B-subunit complementary DNA probes. RESULTS: Both TGF-beta 1 and TGF-beta 2 induced the expression of a 4.8-kb inhibin and activin beta B-subunit messenger (mRNA) transcript in a time- and dose-dependent manner but had no effect on alpha- or beta A-subunit mRNA levels. Human chorionic gonadotropin alone did not affect beta B-subunit mRNA levels, but when administered together with TGF-beta s, it prevented the induction of beta B-subunit mRNAs. CONCLUSIONS: Our results suggest that in human ovary, granulosa, or thecal cell-derived TGF-beta 1 or -beta 2 may eventually locally modulate in a paracrine or autocrine manner the relative expression levels of inhibin and activin subunits favoring the formation of the inhibin and activin dimers containing the beta B-subunit. The effect of TGF-beta is clearly different from that of gonadotropins, which potently induce the alpha- and beta A-subunit mRNAs, indicating that distinct components of the human ovarian inhibin and activin system are regulated differentially by endocrine and local factors.

Activins↗
PubMed1996

Differential regulation of oxytocin and vasopressin messenger ribonucleic acid levels by gonadal steroids in postpartum rats.

We previously reported that sequential estradiol and progesterone exposure followed by progesterone withdrawal increases oxytocin (OT), but not arginine vasopressin (AVP), messenger ribonucleic acid (mRNA) in the hypothalamic paraventricular nucleus (PVN) of the rat. Substitution of testosterone for progesterone and subsequent testosterone withdrawal in the estrogen-primed rat increases PVN AVP mRNA levels. At the end of pregnancy (day 21), rats are exposed to high estrogen and declining progesterone and testosterone concentrations. Coincident with these changes in circulating gonadal steroid hormones in OT and AVP mRNAs. If progesterone levels are sustained at term, OT levels are attenuated and if testosterone is sustained, AVP mRNA levels are attenuated. Immediately postpartum, however, OT and AVP mRNA levels decline compared to term levels. To further determine the role of estrogen in the regulation of OT and AVP mRNAs, we performed two experiments. In the first experiment, we administered estrogen during the peripartum period to determine if estrogen supplementation prevents the relative attenuation of OT and AVP mRNAs that is seen after parturition. Day 18 pregnant rats were given estradiol-filled or empty capsules and sacrificed on day 2 lactation. By Northern analysis, significant differences in PVN AVP, but not OT, mRNA were found between the estrogen- and sham-treated lactational animals, P < 0.02. In the second experiment, we determined if sustaining estrogen after progesterone is removed in steroid-treated ovariectomized rats is essential for the increase in OT mRNA. Ovariectomized rats were given either empty capsules or sequential estradiol- and progesterone-filled capsules and both were sustained for 12 days. When progesterone-filled capsules were removed, estradiol-filled capsules were either removed or left in place, and the animals were sacrificed 48 h later. PVN OT mRNA was analyzed by Northern blot hybridization. OT mRNA was increased in both of the steroid-treated groups to the same degree, compared to sham-treated animals, P = 0.04. In summary, estrogen supplementation during early lactation prevents the attenuation of PVN AVP, but not OT, mRNA after parturition. In the estrogen-primed ovariectomized rat, it is not necessary to sustain estrogen to see the effects of progesterone withdrawal upon PVN OT mRNA.

Animals↗
PubMed1990

High-performance liquid chromatography of transfer ribonucleic acids on spherical hydroxyapatite beads. II. Effects of pH and sodium chloride on chromatography.

The effects of pH and sodium chloride on the high-performance liquid chromatography of transfer ribonucleic acids (tRNAs) on spherical hydroxyapatite beads were investigated. Binding of tRNAs on the beads was strengthened by increasing the pH of the mobile phase (phosphate buffer, pH 6.4-8.0), a phenomenon which is opposite to the retention of proteins on the beads. By using phosphate buffer of pH 8.0 instead of pH 6.8, the resolution of tRNAs was improved significantly; as many as ten times more theoretical plates were calculated with the use of the former buffer. Addition of sodium chloride to the phosphate buffer has a bifunctional effect on the retention of tRNAs: elution of tRNA(f-Met) and tRNA(Val) was retarded whereas that of tRNA(Phe) was facilitated.

Bacillus subtilis↗
PubMed1972

Regulation of synthesis of methionyl-, prolyl-, and threonyl-transfer ribonucleic acid synthetases of Escherichia coli.

Proline- and threonine-restricted growth caused a three- to fourfold derepression of the differential rate of synthesis of the prolyl- and threonyl-transfer ribonucleic acid (tRNA) synthetases, respectively. Similarly, there was approximately a 24-fold derepression in the rate of synthesis of methionyl-tRNA synthetase during methionine restriction. Addition of the respective amino acids to such derepressed cultures resulted in a repression of synthesis of their cognate synthetases. These results support previous findings and further strengthen the idea that the formation of aminoacyl-tRNA synthetases is regulated by some mechanism which is mediated by the cognate amino acids.

Aerobiosis↗

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