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 isomer 9-cis of retinoic acid (9-cis-RA) exerts a beneficial effect on bovine in vitro development when added to in vitro maturation (IVM) culture. In the present work, 9-cis-RA 5 nM was found to be stimulatory as opposed to 500 nM (toxic). Cumulus-oocyte complexes (COCs) were treated with the found physiological dose 9-cis-RA 5 nM, and the next determinations performed: (1) relative expression of midkine (MK) and IGF-I, by reverse transcriptase-polymerase chain reaction (RT-PCR), in cumulus-granulosa cells detached from oocytes; (2) cytoplasmic granular migration, by labeling of oocytes with fluoroscein isothiocyanate lectins; and (3) in vitro survival of blastocysts after vitrification and warming. Gene expression of MK was enhanced by 9-cis-RA, but not by 1% ethanol (vehicle). However, we did not detect IGF-I expression, both in dependence on or in the absence of 9-cis-RA acting on cumulus-granulosa cells. The ability of vitrified blastocysts to survive in vitro was not improved by 9-cis-RA. Nevertheless, since only blastocysts obtained from oocytes matured with serum survived, more factors should be considered when evaluating cryopreservation survival. The complete granular migration observed in oocytes matured with 9-cis-RA anticipates the gain in developmental competence of the oocyte, being MK probably involved in this beneficial effect.
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PMID:9-cis-retinoic acid during in vitro maturation improves development of the bovine oocyte and increases midkine but not IGF-I expression in cumulus-granulosa cells. 1450 3

Alterations in gene expression are thought to help mediate certain effects of alcohol in the brain. We have analyzed the expression of approximately 24,000 genes using oligonucleotide microarrays to examine the brain expression profiles in two strains of inbred mice, C57BL/6J and DBA/2J, following exposure to an acute dose of ethanol. Our screen identified 61 genes responding to the ethanol treatment beyond a 1.5-fold threshold, with 46 genes altered in both mouse strains and 15 altered in only one strain. Approximately 25% of the genes were selected for confirmation by reverse transcriptase polymerase chain reaction with an 87% success rate. The genes identified have roles in cell signaling, gene regulation, and homeostasis/stress response. Although some of the genes were previously known to be ethanol responsive, we have for the most part identified novel genes involved in the acute murine brain response to ethanol. Such genes have the potential to represent candidate genes in the search to elucidate the molecular pathways mediating ethanol's effects in the brain.
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PMID:Microarray analysis of mouse brain gene expression following acute ethanol treatment. 1500 31

Recent outbreaks of severe acute respiratory syndrome (SARS) have spurred intense research efforts around the world to deal with the serious threat to health posed by this novel coronavirus. A rapid, reliable diagnostic assay is needed for monitoring the spread of the disease. Here we report a method for eliminating false-negative results and increasing test sensitivity, based on the hypothesis that the message encoded by the nucleocapsid (N) gene is the most abundant during viral infection. Nasopharyngeal aspirates and stool samples were obtained from suspected SARS patients with major clinical symptoms and a significant history of close contact with infected patients. Total RNAs were extracted in a 96-well format, together with pig kidney epithelial (PK-15) cells as an internal control for extraction efficiency. PCR inhibitors were removed by ethanol precipitation, and a PCR for the pig beta-actin gene was used as a positive control for all clinical samples. Samples were analyzed by a reverse transcriptase PCR assay. Northern blot analysis was performed to demonstrate differences in subgenomic transcripts of the virus, and a real-time quantitative PCR was employed to compare the sensitivities of two loci (1b and N). The detection rate of the assay reached 44.4% on day 9 after the onset of the disease. The diagnostic PCR amplifying the N gene gave an average of a 26.0% (6.3 to 60.0%) stronger intensity signal than that for the 1b gene. In conclusion, the nucleocapsid gene represents an additional sensitive molecular marker for the diagnosis of the SARS coronavirus and can be further adapted for use in a high-throughput platform assay.
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PMID:Reverse transcriptase PCR diagnostic assay for the coronavirus associated with severe acute respiratory syndrome. 1513 Nov 60

Ginseng is one of the most widely used Chinese herbal medicines. In this report, the relatively short-term effect of ginseng extract on the immunoglobulin production and cytokine production was studied. The ginseng extract was prepared by boiling the ground ginseng root in 50% ethanol. The specific pathogen-free mice were intraperitoneally (i.p.) injected with various doses of ginseng extract for 3 consecutive days. The results indicated that the serum levels of immunoglobulin (Ig)M, IgG and IgA were significantly elevated after the mice were i.p. injected with 4 g/kg/day of ginseng extract. Under in vitro condition, the lipopolysaccharide (LPS)-stimulated spleen cells showed a dose-dependent increase in secretion of IgM, IgG and IgA. However, at a higher dosage (4 g/kg/day), the amount of IgA secretion began to decline. The serum level of interleukin (IL)-2, interferon (IFN)-gamma[T-helper (Th) 1-type cytokines] and IL-4 and IL-10 (Th2-type cytokines) were significantly elevated after the mice were i.p. injected with 2 g/kg/day or higher doses of ginseng extract. The amount of cytokine secretion by concanavalin A (Con A)-stimulated spleen cells was also significantly enhanced after the mice were i.p. injected with 0.4 g/kg/day or higher dose of ginseng extracted. To further confirm the results from enzyme-linked immunosorbent assay (ELISA), the spleen cells were cultured for 36 hours in the presence of 1 microgram/ml of Con A. Total mRNA was isolated and assayed for mRNA expression using reverse transcriptase-polymerase chain reaction (RT-PCR). The results revealed that expression of IL-2 and IFN-gamma mRNA were dose-dependently enhanced by the ethanol extract of ginseng. The levels of IL-4 and IL-10 mRNA expression were also elevated in the spleen cells of ginseng-treated mice in comparison with that of the control group. In addition, we observed that the concentrations of IgG1, IgG2a and IgG2b in culture supernatants of spleen cells were dose-dependently increased by in vivo treatment of ginseng extract, suggesting that both Th1- and Th2-type cytokines were involved in IgG production. Our observation in this study demonstrated that the Chinese herbal drug ginseng was able to regulate antibody production by augmenting Th1- (IL-2, IFN-gamma) and Th2-type (IL-4, IL-10) cytokine production.
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PMID:Intraperitoneal injection of ginseng extract enhances both immunoglobulin and cytokine production in mice. 1515 87

Previous studies have demonstrated that ethanol exposure during the vulnerable postnatal (PN) day 4-6 period results in a dose-dependent loss of Purkinje neurons in rats by apoptosis. Although the mechanism of ethanol action and the reasons for Purkinje cell vulnerability are unknown, we hypothesize that during the PN4-6 vulnerable period Purkinje cells are dependent on active trophic factor suppression of apoptosis. Furthermore, ethanol acts to prevent the reception of this trophic signaling resulting in the execution of the apoptotic pathway that includes specific alterations of proteins in the Bcl2 gene family. Ethanol exposure that occurs after this vulnerable period (i.e. PN9) would not be expected to demonstrate alterations in these apoptotic proteins since the Purkinje cells no longer demonstrate vulnerability to ethanol. The current study was undertaken to identify the alterations in mRNA expression for members of the Bcl2-family within the initial hours following ethanol administration on PN4 or PN9. Semi-quantitative reverse transcriptase with polymerase chain reaction (PCR) techniques were used to determine the expression levels of pro-apoptotic factors Bad and Bax, and anti-apoptotic Bcl(2) mRNA. Ethanol was administered at four different doses (1.5, 3.0, 4.5, and 6.0 g/kg) on PN4 and analyses of whole cerebellar mRNA was conducted at 1, 4, 6, and 8 h after treatment. Doses greater than 1.5 g/kg produced significant decreases in Bcl(2) and significant increases in Bad and Bax mRNA during the 8-h period after treatment. In stark contrast, when ethanol was administered at 3.0 or 6.0 g/kg to PN9 pups, no significant alterations of these apoptotic factors were identified at either 1 or 4 h after treatment. These results are in agreement with and provide further support for our hypothesis that ethanol interrupts the active suppression of apoptosis that is a crucial feature of Purkinje cell vulnerability during this time period.
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PMID:Altered expression of Bcl2, Bad and Bax mRNA occurs in the rat cerebellum within hours after ethanol exposure on postnatal day 4 but not on postnatal day 9. 1546 89

Brazilian propolis obtained from honeybee hives was extracted with water or ethanol. Cell growth-inhibitory activities of these propolis extracts were found in HL-60 human myeloid leukemia cells. The extracts-induced apoptosis in the cells, which was characterized by morphological and nucleosomal DNA fragmentation analysis. The apoptosis was mainly attributed to the induction of granulocytic differentiation, which was evaluated by nitro blue tetrazolium (NBT) reducing assays and cytofluorometric analysis for the expression of cell surface marker CD11b. DNA microarray analysis was performed to examine the gene expression profiles in the propolis-treated HL-60 cells accompanied with granulocytic differentiation, which were compared with those in all-trans retinoic acid-treated cells. Several genes were up- or down-regulated. Two genes encoding S100 calcium binding protein A9 and ferritin, heavy polypeptide 1 were up-regulated, which were also confirmed by semi-quantitative reverse transcriptase-PCR (RT-PCR). Propolis-induced growth inhibition in HL-60 cells was, at least in part, due to differentiation with gene expression profiles, which are similar to those induced by all-trans retinoic acid.
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PMID:Effects of propolis on cell growth and gene expression in HL-60 cells. 1584 13

Phyllanthus urinaria Linnea (Euphorbiaceae) is one of the traditional medicinal plants that are widely applied by oriental people, especially by Chinese and Indian, to ameliorate various kinds of ailments. Many biological activities, including anti-hepatitis B virus, anti-Epstein-Barr virus and anti-retroviral reverse transcriptase, of P. urinaria have been reported, but not against herpes simplex virus (HSV). In this study, the anti-HSV-1 and HSV-2 activities of different solvents extracted from P. urinaria were investigated in vitro by plaque reduction assay. Results showed that acetone, ethanol and methanol extracts of P. urinaria inhibited HSV-2 but not HSV-1 infection. The 50% inhibitory concentration against HSV-2 infection (IC50) of acetone, ethanol and methanol extracts was 4.3 +/- 0.5, 5.0 +/ -0.4 and 4.0 +/- 0.9 mcg/ml, respectively. All three extracts showed no cytotoxic effect against Vero cells at concentrations of 10.0 mcg/ml or below. The time-of-addition study demonstrated that these three extracts were only effective when added during the HSV-2 infection which, therefore, suggested that they disturb the initial stage of HSV-2 infection. Furthermore, they can diminish virus infectivity without significantly affecting incubation time and temperature. Therefore, the acetone, ethanol and methanol extracts of P. urinaria were concluded to likely inhibit HSV-2 infection through disturbing the early stage of virus infection and through diminishing the virus infectivity.
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PMID:Acetone, ethanol and methanol extracts of Phyllanthus urinaria inhibit HSV-2 infection in vitro. 1588 15

Water and 80% ethanol extracts of 20 Thai medicinal plants used to treat AIDS were tested for their HIV type 1 reverse transcriptase inhibitory activity. The water extracts of Ipomoea carnea subsp. fistulosa (aerial parts), Vitex glabrata (branch), Vitex trifolia (aerial part), Vitex negundo (aerial part), Canna indica (rhizome), and Justicia gendarussa (aerial part) showed HIV-1 RT inhibition ratio (% IR) higher than 90% at a 200 microg/ml concentration. The water extract of Canna indica rhizomes (IC(50) 22.56 microg/ml) was selected for further study, i.e. for its HIV-1 RT inhibition activity and the purification and characterization of the active proteins. Proteins in water extract were fractionated by ammonium sulfate precipitation and separated by sodium dodecyl sulfate acrylamide gel electrophoresis (SDS-PAGE), yielding two proteins, Cip31 (31 kDa) and Cip14 (14 kDa) with IC50 of 17.41 and 19.25 microg/ml and isoelectric point (pI) of 3.5 and 6.35, respectively. Both proteins showed significant HIV-1 RT inhibition.
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PMID:In vitro HIV type 1 reverse transcriptase inhibitory activities of Thai medicinal plants and Canna indica L. rhizomes. 1595 Nov 45

The murine embryonal teratocarcinoma cell line, P19, was genetically manipulated in order to provide preliminary information on compounds that induce differentiation. Without chemical induction, P19 cells remain in an undifferentiated state, but can be induced to differentiate into specific cell types. For example, dimethyl sulphoxide (DMSO) induces cardiac and skeletal muscle differentiation, whereas retinoic acid stimulates neuronal differentiation. P19 cells were transfected with a construct containing a segment of the murineTert (mTert) promoter sequence combined with the green fluorescent protein (GFP) gene, which acts as a reporter gene. mTert expression, the reverse transcriptase component of murine telomerase, is closely linked to telomerase activity and is down-regulated during differentiation. Three retinoids and DMSO induced the differentiation of P19 cells, which was determined by a reduction in mTert_GFP expression, detected by flow cytometry and confocal microscopy as independent methods of detection. A test substance, ethanol, and a control substance, saccharin, did not cause a decrease in mTert_GFP expression. In addition, it could be demonstrated that the mTert_GFP test detects developmentally relevant effects at non-cytotoxic concentrations. The ID50 values derived for the reduction of mTert_GFP expression were lower than the IC50 values detected with the MTT test, by a factor of 21.4 for all-trans retinoic acid, 12.7 for 9-cis retinoic acid, 29.6 for 13-cis retinoic acid, and 8.7 for DMSO. In comparison to the IC50 value for the P19 cell line, a similar IC50 value was obtained with 3T3 cells for ethanol, but there was a 2-fold increase for DMSO. The retinoids were not cytotoxic to 3T3 cells at the concentrations tested. This newly developed test is capable of detecting differentiation-inducing compounds at non-cytotoxic concentrations within 4 days. It offers a method for detecting chemicals with specific toxicological mechanisms, such as the retinoids, which could provide additional information in embryotoxicity testing as different promoters could be employed. Here, we report the use of this novel test system for the successful analysis of DMSO and three retinoids with different in vivo teratogenic potentials.
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PMID:The detection of differentiation-inducing chemicals by using green fluorescent protein expression in genetically engineered teratocarcinoma cells. 1618 Sep 84

In vivo studies have shown that chronic alcohol consumption sensitizes the liver to endotoxemic shock, leading to liver microcirculation disruption. In the present study, we investigated the molecular mechanisms involved, focusing on endothelial nitric oxide synthase (eNOS) activity and regulation, which represents one of the major vasodilatory pathways. Male Sprague-Dawley rats were fed an alcohol liquid diet or a control isocaloric diet for 5 weeks. Priming effects of ethanol were studied in a model with or without a 24-h LPS treatment (1 mg/kg body weight). At the end of the diet, liver tissue was harvested for western blot, reverse transcriptase-PCR, histological analysis, and immunostaining and blood for serum alanine aminotransferase analysis. Chronic ethanol and LPS alone induced a mild hepatitis and infiltration, respectively. Combined, LPS and chronic ethanol feeding showed a synergistic effect on the liver, leading to extensive steatohepatitis with extensive focal necrosis associated with significantly higher levels of serum ALT. Chronic ethanol and LPS significantly inhibited eNOS activity, but exerted their effects through different mechanisms. Caveolin-1, an eNOS inhibitory protein, was upregulated after LPS and chronic alcohol consumption. Additionally, chronic alcohol consumption down-regulated endothelin B receptor, eNOS protein levels, and eNOS phosphorylation. In conclusion, chronic ethanol consumption and LPS share a similar pathophysiology and both lead to the impairment of eNOS activity, but through distinct molecular mechanisms. The presence of focal necrosis in a mild stress model could provide a good animal study to investigate the advanced stages of alcoholic liver diseases.
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PMID:Chronic ethanol sensitizes the liver to endotoxin via effects on endothelial nitric oxide synthase regulation. 1624 31


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