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

---

Query: EC:2.7.7.48 (transcriptase)
9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biotinylated complementary DNA (cDNA) and RNA probes were prepared from a specific and highly conserved section of the foot-and-mouth disease virus (FMDV) genome coding for the RNA-dependent RNA polymerase. Hybridization was conducted on FMDV-infected, bovine enterovirus (BEV)-infected, and noninfected swine kidney cell cultures. The detection system utilized the enzyme system streptavidin-alkaline phosphatase, the substrate phosphate, and the chromogen nitroblue tetrazolium. Intense cytoplasmic granular staining was present at 2 and 4 hr postinfection (hpi), with less staining observed at 24 hpi. The staining was specific for FMDV, as indicated by a lack of staining of noninfected cells and BEV-infected cells. With the RNA probe, positive cells were detected up to the highest viral dilution assayed, which was approximately 96 TCID50. The cDNA probe was slightly less sensitive, detecting positive cells at 10-fold lower dilutions. This technique could prove useful in the diagnosis of foot-and-mouth disease in animals or in the detection of FMDV in biologics submitted for importation.
...
PMID:Use of in situ hybridization for the detection of foot-and-mouth disease virus in cell culture. 256 24

A pancreatic ribonuclease digest of (14)C-labeled tobacco necrosis virus RNA was fractionated according to charge by column chromatography. Individual fractions were dephosphorylated with alkaline phosphatase and rechromatographed. The fraction, originally containing oligonucleotides with seven negative charges, separated into two components corresponding to five (-5) and two negative charges (-2). The -5 fraction was derived from the internal oligonucleotides while the -2 fraction must have originated from a 5'-pyrophosphorylated terminal trinucleotide. The sequence of this terminal trinucleotide was determined by column chromatography on DEAE-cellulose in a triethyl ammonium carbonate gradient, using the appropriate markers. The radioactivity chromatographed with a (ApGp)U marker. The order of the Ap and Gp was determined after ribonuclease T(1) and alkaline phosphatase digestion. The radioactivity in the product chromatographed with an ApG marker. The 5'-terminus of tobacco necrosis virus RNA was therefore determined as ppApGpUp..., which is identical to the terminus of the RNA of its satellite virus as previously determined (J. Mol. Biol., 38, 59 (1968); Science, 160, 1452 (1968)). The 5' pyrophosphate in both viruses was probably formed by an in vivo enzymatic removal of a gamma-phosphate from a triphosphate, and its presence in both viruses suggested a common site of synthesis. The identity of the 5'-terminal sequences is considered not to be fortuitous and is discussed from the standpoint of their role as a recognition site for the virus-specific RNA replicase.
...
PMID:Identity of the 5'-terminal RNA nucleotide sequence of the satellite tobacco necrosis virus and its helper virus: possible role of the 5'-terminus in the recognition by virus-specific RNA replicase. 527 92

The expression pattern of tissue nonspecific alkaline phosphatase (TNAP) in the developing neural tube of mouse is reported. Homogeneous AP activity in the neuroepithelium becomes prominent at E8.5. At E9.5, distinctly AP-positive cells appear in the brain and spinal cord area. At stages E10.5 to E12.5, AP positivity is observed between the mesencephalon and the rhombencephalon, along the entire spinal cord and cranial nerves emerging from the myelencephalon. At E13.5, strongly AP positive fibers become prominent in the pons. At E14.5, AP expression in brain tissue is considerably reduced and there is a complete absence of AP activity in the nerve cells and glial cells of adult brain. The choroid plexus remains distinctly positive for AP expression until the adult stage. Northern blot analysis and reverse-transcriptase polymerase chain reaction amplification of RNA indicate that this AP activity results from the expression of the Akp-2 locus. This AP expression pattern is distinct from those reported for the expression of GD3, nestin, Hox 2.3, and Wnt-1 during brain development. We conclude that AP is a useful marker of a subpopulation of neuroectodermal cells present in the neural tube as early as E8.5, at which stages there are no other AP positive intraembryonic cells except PGCs.
...
PMID:Stage-specific expression of alkaline phosphatase during neural development in the mouse. 753 63

There is evidence suggesting the importance of the interleukin-1 receptor type I (IL-1Rtl) and interleukin-1 beta (IL-1 beta) as mediator in local intercellular interactions in endometrial tissue and embryonic implantation. To complete our understanding of the entire endometrial IL-1 system in humans, we have investigated the immunohistochemical distribution of IL-1 receptor antagonist (IL-1ra) in the human endometrium throughout the menstrual cycle. We have also identified the forms of IL-1ra present in human endometrial cells. Immunoreactive IL-1ra was found in both cryostat and paraffin-embedded sections of human endometrium using the alkaline phosphatase-peroxidase (A-P) method with two different IL-1ra antibodies. IL-1ra was present throughout the entire menstrual cycle, located primarily in the endometrial epithelium. However, IL-1ra staining was significantly higher during follicular phase in comparison with early and mid-late luteal phases. Reverse transcriptase polymerase chain reaction of cultured stromal and glandular cells showed that these cells express the intracellular form of IL-1ra mRNA (icIL-1ra). Our results demonstrate the regulated presence of the icIL-1ra in the human endometrium. This finding supports a possible autocrine-paracrine role for the IL-1 system in the human endometrium and embryonic implantation.
...
PMID:Immunohistochemical localization, identification and regulation of the interleukin-1 receptor antagonist in the human endometrium. 853 Jun 93

A dot blot hybridization assay was developed for detection of human calicivirus/Sapporo/82/J (HuCV/Sa/82) or strains closely related to HuCV/Sa/82 in stool specimens. The cDNA derived from the RNA-dependent RNA polymerase (RDRP) region of HuCV/Sa/82 was used as a positive probe and the pBR322 DNA as a negative control probe. Both probes were labeled with digoxigenin and the products of hybridization reaction were detected with an anti-digoxigenin antibody-alkaline phosphatase conjugate. This assay was specific for HuCV/Sa/82 and for HuCV antigenically related to HuCV/Sa/82. The lower limit of sensitivity of this assay was estimated to be about 10(5) physical particles or 10 pg of cDNA, similar to that of the previously developed ELISA for HuCV. In 1273 stool specimens obtained from children with acute gastroenteritis in Sapporo, Japan, 110 (8.6%) contained small round structured viruses by EM and 23 (1.8%) were positive for HuCV antigenically related to HuCV/Sa/82 by either the hybridization assay or ELISA. A higher positive rate was obtained with the dot blot assay (21%) than by ELISA (10%), suggesting that the dot blot assay either detects HuCV more broadly than the ELISA or detects HuCV covered with fecal antibodies which interrupt antigen-antibody reactions in the ELISA. Negative results for detection of Norwalk virus (NV) cDNA and feline calicivirus (FCV) RNA by both this assay and the ELISA indicated that the HuCV/Sa/82 strain is distinct antigenically and genetically from NV and FCV.
...
PMID:Dot blot hybridization with a cDNA probe derived from the human calicivirus Sapporo 1982 strain. 892 Aug 27

Three clonally related T-cell lymphoma lines (PB-1, 2A, and 2B) were examined for expression of IL-2, IL-4, and their receptors. All three lines were derived from a single patient who had an atypical, progressive T-cell lymphoproliferative disorder involving primarily skin (Davis, T.H. et al. 1992, N. Engl. J. Med. 326:1115). The PB-1 cell line was obtained from a relatively early, clinically indolent stage of the cutaneous lymphoma, whereas the 2A and 2B lines were established from a late, aggressive stage of the lymphoma. Reverse-transcriptase PCR performed with primer pairs specific for IL-2 and IL-4 showed that no mRNA coding for these cytokines was present in any of the lines with the exception of IL-4 mRNA in the 2A line. No IL-4 protein, however, was found in any of the cell lines including 2A by immunocytochemical staining with anti-IL-4 mAb. Accordingly, no bioactive IL-4 was present in the supernatants of these lines. In contrast, all three T-cell lymphoma lines contained mRNA for IL-2R alpha, IL-2R beta, IL-4R and common gamma chain. Immunocytochemical analysis revealed that only the PB-1 line stained strongly with mAbs specific for IL-2R alpha, IL-2R beta, and IL-4R whereas the 2A and 2B lines showed only limited staining with these mAbs. In contrast to expression of IL-2R alpha and IL-4R primarily on the cell surface, IL-2R beta was localized mainly in the cell cytoplasm. Testing supernatants of the cell lines by ELISA for the presence of soluble alpha chain of the IL-2R (sIL-2R) has shown that only PB-1 secreted a large amount of sIL-2R, whereas the 2A and 2B lines secreted lesser amounts. Furthermore, the PB-1 cells expressed a relatively large number of IL-4R as determined by IL-4 binding studies using an IL-4-alkaline phosphatase fusion protein. The remaining two lines displayed only limited binding of IL-4. Addition of IL-2 and/or IL-4 to the culture medium did not modulate growth of PB-1 and the other two lines. These findings may indicate that at least some types of T-cell lymphoma evolve from cells which lose the capacity to synthesize T-cell autocrine growth factors such as IL-2 and IL-4, and show progressive loss of receptors for these cytokines.
...
PMID:Analysis of IL-2, IL-4 and their receptors in clonally-related cell lines derived from a patient with a progressive cutaneous T-cell lymphoproliferative disorder. 902 95

Cytokine-driven activation of hepatic stellate cells (HSC) in tissue injury and inflammation is a key pathogenetic event in liver fibrogenesis leading to an expanded pool of matrix producing myofibroblasts (MFB) which represent the transformed counterpart of HSC. We hypothesize that expansion of the pool of MFB might also be accomplished by modulation of apoptosis, which plays an opposite and complementary role to mitosis in the cellular homeostasis. We characterized the susceptibility of HSC in primary culture and of MFB in secondary culture to apoptosis induced by the soluble Fas ligand (sFasL) and related the effects to the expression levels of Fas (APO-1/CD95) and some major proapoptotic and contra-apoptotic protooncogenes. MFB showed a dose-dependent apoptotic reaction upon exposure to sFasL as evidenced by a strong increase of nucleosomal DNA fragments, loss of cellular DNA, positive TUNEL reaction, and annexin staining. The effect was found only if protein synthesis (cycloheximide) or RNA synthesis (actinomycin D) were arrested. HSC maintained for various times in primary culture were completely resistant to sFasL in combination with cycloheximide, but in late primary cultures (day 7 onward) an increasing susceptibility to sFasL-mediated apoptosis was developed. By semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis and alkaline phosphatase-anti-alkaline phosphatase staining Fas receptor was identified both in HSC and MFB at comparable expression levels. The expression of the contra-apoptotic protooncogenes bcl-2 and bcl-xl was found to be much stronger in early HSC than in late HSC and MFB as shown by ribonuclease protection assay. The expression of bcl-2 was additionally confirmed by semiquantitative RT-PCR and immunoblotting. Proapoptotic bax was found in comparable quantities at the RNA level in HSC and MFB but at the protein level MFB showed increased bax expression. It is concluded that transformation of HSC to MFB is paralleled by an increasing sensitivity to sFasL-mediated apoptosis, which might be related to a strong decrease of bcl-2 and bcl-xl expression, leading to a preponderance of proapoptotic gene expression in MFB. Modulation of apoptotic susceptibility of transforming HSC could be an important complementary pathway in the pathogenesis of fibrosis.
...
PMID:Transformation-dependent susceptibility of rat hepatic stellate cells to apoptosis induced by soluble Fas ligand. 969 16

In this study, the effects of incubating two clonal rat osteoblastic cell lines at different stages of differentiation, ROB-C26 (C26) and ROB-C20 (C20), with transforming growth factor-beta1 (TGF-beta1) on the gene expression of decorin, biglycan, and alkaline phosphatase were examined. C26 cells are a potential osteoblast precursor cell line that is also capable of differentiating into muscle cells and adipocytes and is differentiated into osteoblasts after treatment with bone morphogenetic protein-2. C20 cells are a more differentiated osteoblastic cell line. Our Northern blot studies demonstrated that after treatment with TGF-beta1 (0, 0.1, 1.0, 5.0, and 10 ng/ml), a dose- and time-dependent decrease in decorin mRNA expression was found in C26 cells. In contrast, the effect of decorin mRNA with TGF-beta1 was not determined in C20 cells, since decorin mRNA expression was extremely low in this cell line even in the absence or presence of TGF-beta1. Although TGF-beta1 treatment resulted in no appreciable effect on biglycan mRNA expression in both cell lines in a dose- and time-dependent manner, it decreased significantly the expression of alkaline phosphatase in both cell lines at the gene and protein level. Reverse transcriptase-polymerase chain reaction analysis revealed the gene expression of decorin, and TGF-beta type I and type II receptors in both cell lines. These results indicate that osteoblasts progenitor cells express both decorin and biglycan mRNAs. In contrast, more differentiated and mature osteoblastic cells express preferentially biglycan mRNA. TGF-beta1 exerts different effects on the expression of decorin and biglycan mRNAs, and is a potent inhibitor of the gene expression of alkaline phosphatase during osteoblast differentiation.
...
PMID:Effects of transforming growth factor-beta1 on the gene expression of decorin, biglycan, and alkaline phosphatase in osteoblast precursor cells and more differentiated osteoblast cells. 1057 18

Osteoblasts express protease-activated receptor-1 (PAR-1), which is activated by thrombin or by synthetic peptides corresponding to the new "tethered ligand" N-terminus of PAR-1 created by receptor cleavage. Both thrombin and human PAR-1-activating peptide stimulate an elevation of [Ca2+]i in the human SaOS-2 osteoblast-like cell line, but the peptide stimulates receptor-mediated Ca+ entry, whereas thrombin does not. Stimulation of proliferation in rat primary osteoblast-like cells is greater in response to rat PAR-1-activating peptide than to thrombin. Because the PAR-1-activating peptides are now known to activate PAR-2, the current study was undertaken to investigate whether osteoblasts express this receptor and, if so, whether this could account for the observed discrepancies between responses of osteoblasts to thrombin and to PAR-1-activating peptides. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemical studies demonstrated expression of PAR-2 by primary cultures of rat calvarial osteoblast-like cells. In immunohistochemical studies of embryonic mouse bones, osteoblasts showed positive staining for the presence of PAR-2. Activators of PAR-2 include trypsin, mast cell tryptase, gingipain-R, and synthetic peptides corresponding to the PAR-2 tethered ligand sequence. Treatment of primary rat osteoblast-like cells with rat PAR-2-activating peptide (SLIGRL), or SaOS-2 cells with human PAR-2-activating peptide (SLIGKV), caused a dose-dependent increase in [Ca2+]i. Trypsin or gingipain-R also induced an increase in intracellular calcium concentration, and caused reciprocal cross desensitization. Activators of PAR-2 caused a sharp peak in [Ca2+]i followed by a sustained plateau; [Ca2+]i returned to baseline levels upon treatment with ethylene-glycol tetraacetic acid (EGTA). Treatment of rat osteoblast-like cells in vitro with SLIGRL did not affect thymidine incorporation or endogenous alkaline phosphatase activity. The results presented here demonstrate that osteoblasts express PAR-2, and that such expression is able to account for the observed discrepancies between thrombin and PAR-1-activating peptides in their ability to evoke calcium entry, but not proliferative responses.
...
PMID:Expression of protease-activated receptor-2 by osteoblasts. 1061 51

The genome of Japanese iris necrotic ring virus (JINRV) consists of a positive-sense ssRNA of 4014 nucleotides with six major open reading frames (ORFs). A 5'-non-coding region of 31 nucleotides precedes the first initiation codon. Like Carnation mottle virus (CarMV), the 5'-proximal three ORFs encode a 26 kDa protein (p26) and two readthrough proteins, i.e. an 85 kDa putative RNA replicase (p85) and a 99 kDa protein (p99). The central ORF encodes a small 8 kDa protein (p8). The 3'-proximal ORF encodes a 38 kDa capsid protein (p38). Another ORF encoding a 12 kDa protein (p12) overlaps the p99 ORF.JINRV RNA treated with bacterial alkaline phosphatase and tobacco acid pyrophosphatase could not be ligated to an oligoribonucleotide using T4 RNA ligase, indicating that the 5' end of the viral RNA is uncapped. The 3' end is not polyadenylated. Comparison of the genomic organization and the predicted amino acid sequences with those of other viruses confirmed that JINRV should be classified as a member of the genus Carmovirus, family Tombusviridae.
...
PMID:The nucleotide sequence and genome organization of Japanese iris necrotic ring virus, a new species in the genus Carmovirus. 1079 30


1 2 3 4 5 Next >>

---