Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of bromodeoxyuridine (BrdUrd) incorporation into hepatocytes of carbon tetrachloride (CCl4)-induced regenerating liver of BALB/c mice on the induction of endogenous retroviruses was examined. From the nucliec acid hybridization studies, the maximum levels of hybridization were obtained for both N- and X-tropic BALB/c endogenous retrovirus specific [3H]-cDNAs with liver RNA from animals receiving BrdUrd at 40 and 44 h post-CCl4 treatment, and killed on the fourth day following BrdUrd injection. Media from NIH-3T3 (Swiss mouse) and mink cell cultures, infected with liver homogenates from animals treated as above, gave significant levels of reverse transcriptase activity. The observations made in the present study show that BrdUrd incorporation into cell DNA can cause induction of both N- and X-tropic endogenous retroviruses in BALB/c mouse hepatocytes in vivo, and such induction is probably a transient event.
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PMID:In vivo induction of endogenous retroviruses in BALB/c mouse hepatocytes by successive treatments with carbon tetrachloride and bromodeoxyuridine. 9 80

Antiviral and antileukaemic effects of the synthetic (2'-5')-oligoadenylate trimer [(2'-5')-ApApA] were demonstrated in BALB/c mice infected with Rauscher murine leukaemia virus (RMLV) by intraperitoneal (i.p.) treatment for 5-20 days (100 micrograms--1 mg daily doses) as evidenced by 72% suppression of viraemia and by decreased activity of serum reverse transcriptase levels. Electron microscopy revealed more than 95% inhibition of RMLV replication as compared to controls in transformed spleen cells from mice treated 5 times with 1 mg dose of (2'-5') ApApA. A significant and dose-dependent reduction of spleen weights of the RMLV-infected mice treated with (2'-5') ApApA was also observed. The antileukaemic effect of (2'-5-') ApApA was enhanced by simultaneous i.p. injection of amphotericin B (20 micrograms/mouse). In comparison to the effect of interferon (IFN) on RNA tumour viruses, our results suggest a higher antiviral activity of the synthetic (2'-5') ApApA oligonucleotide in suppressing RMLV replication in vivo.
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PMID:Antiviral and anticellular effects of synthetic (2'-5')-oligoadenylate (A 2' p 5' A 2' p 5' A) in Rauscher murine leukaemia. 614 Aug 32

A polymerase chain reaction (PCR) for the detection of hantavirus genome was established and applied to analyze the mode of infection of Hantaan virus in adult ICR mice. The cDNA for the S genome segment of Hantaan virus was reverse-transcribed from the total RNA of organs of the infected mice. The sequence in the S genome segment of Hantaan virus was successfully amplified by reverse transcriptase (RT)-PCR followed by nested PCR. In 5-week-old ICR mice inoculated intraperitoneally with Hantaan virus, strain 76-118 (1.3 x 10(5) FFU/mouse), the virus was detected in clots and lungs from 3 to 10 days post-inoculation (p.i.) by nested PCR and virus-isolation techniques. No virus was detected in any specimens collected on 1 day and after 28 days p.i., and in spleens and brains through the observation period by both methods. The antibody which was measured by indirect immunofluorescence antibody assay (IFA) appeared at 7 days p.i. and the geometric mean titer was elevated to its maximum level of 1:203 at 10 days p.i., maintaining the same level until 35 days p.i. These results suggest that adult mice are transiently infected with Hantaan virus.
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PMID:Characterization of the mode of Hantaan virus infection in adult mice using a nested reverse transcriptase polymerase chain reaction: transient virus replication in adult mice. 778 76

OL-2, a highly branched (1-->3)-beta-D-glucan, is an antitumor glucan showing strong hematopoietic activity with weaker adjuvant activity than schizophyllan (SPG), another antitumor glucan and one which is used clinically. This paper deals with the gene expression of cytokines in mice by OL-2 and SPG in order to characterize their immunopharmacological activity. Gene expression was examined by a reverse transcriptase-polymerase chain reaction method after intraperitoneal administration of OL-2 or SPG (250 micrograms/mouse). The OL-2 administered mice strongly expressed the interleukin 1 receptor antagonist (IL-1ra) gene but SPG administered mice did not. The difference would be strongly related to the antigen-specific response between OL-2 and SPG. In the genes related to haematopoiesis, OL-2 induced G-CSF and GM-CSF, but SPG induced IL-3. These differences would relate to the pattern of haematopoietic response. Comparing the cytokine gene expression in ICR and AKR mice by OL-2 administration, the changes in cytokine gene expression were less in AKR mice administered OL-2. These findings suggest that the immunopharmacological characteristics of OL-2 are closely related, at least in part, to the activation of the complement system. The data shown in this paper also suggest that cytokine gene expression by beta-glucan would be significantly affected by the structure of these glucans.
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PMID:Analysis of cytokine mRNAs induced by the administration of a highly branched (1-->3)-beta-D-glucan, OL-2. 800 Mar 84

Mammalian genes encoding a 35-kDa peroxisomal membrane protein (PMP35, peroxisome assembly factor-1) are compared using the polymerase chain reaction and DNA sequencing. DNA sequencing of the 915 bp of the PMP35 coding regions was in complete agreement with previously published rat data and showed 36 and 133 nucleotide substitutions, respectively, in mouse and man. The 12 and 35 respective amino acid changes encoded by these nucleotide substitutions are clustered and compatible with putative membrane-spanning regions. Rat/human and rat/mouse comparisons yield silent mutation rates of 0.33 and 0.21% per site per million years and replacement mutation rates of 0.082 and 0.076%; transitions account for 67% (human/mouse) and 83% (rat/mouse) of nucleotide replacements among PMP35 genes. PMP35 gene expression in mouse tissues as measured by reverse transcriptase-PCR was responsive to clofibrate and disproportionately high in neural tissue.
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PMID:Structure and expression of mammalian peroxisome assembly factor-1 (PMP35) genes. 804 97

The nucleoside analogue, 2',3'-dideoxycytidine (ddC), a potent inhibitor of human immunodeficiency virus reverse transcriptase (in its anabolized triphosphorylated form), mediates virologic and immunologic improvements in AIDS patients. Clinical studies using ddC have shown various ddC-related toxicities, the most pronounced being a dose-limiting peripheral neuropathy. The dose responsiveness and manifestation of the ddC-related neuropathy vary among species, with greatest sensitivity in human > monkey > rabbit whereas mice and rats are insensitive to ddC-related neuropathy. This study has examined nucleotide pool sizes of ddCTP and its constituents (ddC, ddCMP, ddCDP) in cultured fibroblasts (human, rabbit, mouse) and freshly isolated peripheral lymphocytes (monkey, rabbit, rat, and mouse). Cells were treated with 10 microM [3H]ddC and nucleotide pool sizes analyzed by HPLC. The formation of nucleotide pools increased during the 24-hr assay period. Fibroblast pool formation of phosphorylated metabolites was significantly greater in human > rabbit > mouse. Lymphocytes demonstrated a similar pattern with monkey > rabbit > mouse = rat. Total ddC anabolite pools were also found to be significantly smaller (p < 0.05) in rodent lymphocytes than in those of rabbit or monkey, and rodent fibroblasts were smaller than those of human or rabbit (p < 0.05). These findings indicate that nucleoside phosphorylation and intracellular levels of phosphorylated metabolites may play an important role in determining species sensitivity and manifestation of ddC-related toxicity.
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PMID:Species differences in nucleotide pool levels of 2',3'-dideoxycytidine: a possible explanation for species-specific toxicity. 823 52

OL-2, a highly branched (1-->3)-beta-D-glucan, is an antitumor glucan showing strong hematopoietic activity with weaker adjuvant activity than schizophyllan (SPG), also an antitumor glucan and one which is clinically used. This paper deals with the gene expression of the interleukin 1 (IL-1) family in mice by OL-2 and SPG in order to characterize the immunopharmacological activity. Gene expression was examined by reverse transcriptase-polymerase chain reaction method. Intraperitoneal administration of OL-2 (250 micrograms/mouse) expressed all three genes of IL-1 alpha, beta, and IL-1 receptor antagonist (IL-1ra) in the peritoneal exudate cells, while SPG induced a strength of IL-1 alpha mRNA comparable to that by OL-2 but a weaker level of IL-1 beta mRNA. SPG did not induce IL-1ra. Similar patterns were seen in spleen and liver by OL-2 or SPG administration. These findings suggest that the immunopharmacological characteristics of (1-->3)-beta-D-glucan are regulated under the gene expression of the IL-1 family.
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PMID:Expression of interleukin 1 family mRNAs by a highly branched (1-->3)-beta-D-glucan, OL-2. 828 38

Adult rodent (rat and mouse) prostatic ducts (PR) were recombined heterospecifically with fetal urogenital sinus mesenchyme (UGM) (mouse UGM plus rat PR or rat UGM plus mouse PR), and the resultant tissue recombinants were grafted under the renal capsule of male athymic mice. For recombination with mouse UGM the ductal tips of each of the 4 rat prostatic lobes [ventral (VP), lateral type 1 (L1), lateral type 2 (L2), and dorsal prostate (DP)] were used. For recombination with rat UGM the ductal tips of each of the 2 mouse prostatic lobes [ventral (VP) and dorso-lateral prostate (DLP)] were used. After 1 month of growth in vivo, the DNA content of UGM+PR recombinants increased substantially (6.1- to 76.8-fold increase) over the combined DNA content of the isolated UGM and PR prior to grafting. Immunocytochemical, polyacrylamide gel electrophoretic and Western blot analyses demonstrated that irrespective of the initial source of the adult prostatic duct, the epithelium of UGM + PR recombinants continued to express its normal lobe-specific secretory proteins as well as secretory proteins specific to other prostatic lobes. For example, rat ventral and lateral type 2 prostate do not normally express DP-1, a rat dorsal-prostatic-specific protein, but after recombination with mouse UGM the induced prostatic epithelium expressed DP-1 as well as C3, a rat ventral-prostatic-specific protein. Sensitive reverse transcriptase-polymerase chain reaction techniques (RT-PCR) verified the expression of mRNA for C3 and DP-1 in such tissue recombinants. Analogous results were obtained for UGM + PR tissue recombinants constructed with prostatic ductal tips from rat L1, L2 and DP and mouse VP and DLP. These findings demonstrate that adult rodent prostatic epithelium retains a responsiveness to its connective tissue environment, and that fetal UGM can permissively induce prostatic ductal growth and morphogenesis while instructively inducing the expression of a new spectrum of prostatic secretory proteins.
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PMID:Permissive and instructive induction of adult rodent prostatic epithelium by heterotypic urogenital sinus mesenchyme. 835 95

Human CD4, the receptor for the gp120 envelope glycoprotein of HIV-1, is the route for viral entry into CD4+ cells; other cellular factors may cooperate with CD4 to facilitate HIV-1 entry into human cells. Human CD4 expressed on murine cells does not readily mediate HIV-1 entry, which may reflect a functional incompatibility of human CD4 with murine cellular components. We postulated that a HIV-1 gp120-binding mutant murine CD4 (L3T4) possessing a minimal number of human amino acid residues could facilitate HIV-1 entry into rodent cells, unlike human CD4. This hypothesis led us to develop a series of murine L3T4 mutants that bear human CD4 gp120-binding region amino acid residues while retaining most L3T4 epitopes. HeLa cell transfectants expressing gp120-binding mutant L3T4 proteins could be infected with HIV-1. Three mouse cell lines expressing these L3T4 mutant proteins could also be infected with HIV-1 as determined by PCR techniques that detect viral DNA and spliced RNAs. Lectin-stimulated polymorphonuclear leukocytes from transgenic mice (SBL mouse) expressing a gp120-binding L3T4 mutant protein were infected with HIV-1 at the same frequency as lectin-stimulated human peripheral blood lymphocytes as determined by in situ PCR analyses. Supernatant p24gag and reverse transcriptase levels in HIV-infected mouse cell cultures, however, were routinely at background levels, unlike HIV-infected human cell cultures. Thus, gp120-binding mutant L3T4 proteins mediate viral entry in all mouse cells that were tested, but high-level viral replication is absent in these cells.
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PMID:Human immunodeficiency virus type 1 entry into murine cell lines and lymphocytes from transgenic mice expressing a glycoprotein 120-binding mutant mouse CD4. 879 71

Nitric oxide (NO) is an important effector molecule on antimicrobial and antitumor effects of macrophages. (1 -> 3)-beta-D-Glucan (beta-glucan) is well known to show various immunopharmacological effects such as antimicrobial effect and antitumor effect by activating various points of host defense mechanisms. This paper deals with NO synthetic activity of peritoneal macrophage (PM) induced by beta-glucan administration in mice. The activity was determined by measuring NO concentration in PM culture by Griess reagent after 24 or 48 h in vitro culture. Administration (i.p. or i.v.) of a branched soluble (1 -> 3)-beta-D-glucan, grifolan (GRN), from Grifola frondosa enhanced NO synthesis of PM dose and time dependently. The activity was abrogated by the addition of N(G)-monomethyl-L-arginine (L-NMMA) in vitro. The most significant activity was observed at 3-7 d after the administration of GRN (250 mu g/mouse). PM from all strains of ICR, C3H/HeN, C3H/HeJ, BALB/c, BALB/c nu/nu, C57BL, and AKR mice showed significant activity by GRN administration. Among beta-glucans tested, SSG and OL-2, highly branched soluble glucans, and a particulate beta-glucan, zymosan, showed similar activity. Addition of GRN directly to in vitro RAW 264.7 or proteose peptone induced peritoneal macrophage (PP-PEC) culture could not enhance NO synthesis. However, NO synthesis of PP-PEC was enhanced in vitro by addition of GRN in the presence of interferon gamma (IFN gamma). Gene expression of IFN gamma mRNA in the liver and PEC were enhanced in GRN administered mice assessed by reverse transcriptase assisted PCR (RT-PCR) method. These facts strongly suggested that beta-glucan has capacity to enhance NO synthesis of PM in vivo through IFN gamma mediated mechanism.
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PMID:Effect of beta-glucans on the nitric oxide synthesis by peritoneal macrophage in mice. 886 Sep 68


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