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Results for “Reverse Transcriptase Polymerase Chain Reaction”

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At least 19 recordsLinked to original sources
PubMed1990

Use of reverse transcriptase polymerase chain reaction to monitor expression of intronless genes.

Our data demonstrate the use of the reverse transcriptase polymerase chain reaction (RT-PCR) technique to study mRNA expression of genes that are devoid of introns. We have developed conditions that eliminate the false positives that can result from any preexisting DNA and that could confuse the interpretation of results. This modification (DNase pretreatment under specified conditions) ensures that the product resulting from RT-PCR is due to amplification of cDNA that has been synthesized during the reverse transcriptase reaction. Our results illustrate and emphasize the importance of including both a DNase pretreatment and a minus RT control. Using this modified procedure, our data illustrate clearly the ability of this protocol to demonstrate the presence of very low levels of olfactory marker protein (OMP) mRNA in three non-olfactory rat brain regions (cerebellum, thalamus/hypothalamus and cerebral hemispheres) where OMP mRNA was previously unknown. These data confirm a prior report of the ectopic expression of OMP immunoreactivity in these locations and indicate for the first time the "illegitimate" expression of extremely low levels of OMP mRNA in a non-neural tissue. Finally, this modification of the RT-PCR procedure will now permit the study of expression of specific, rare, mRNA molecules in the absence of any prior knowledge of the structure of their genes of origin.

Animals↗
PubMed1992

Detection of platelet-specific protein mRNAs in different megakaryoblasts using the reverse transcriptase polymerase chain reaction.

The short segments of cDNA encoding glycoprotein (GP)Ib alpha, GPIIb, GPIIIa and platelet factor (PF) 4 were amplified using reverse transcriptase-polymerase chain reaction (RT-PCR) in order to characterize various types of megakaryoblasts. Cell lines with megakaryocytic features (K562, CMK and HEL) were tested. GPIb alpha, GPIIb and GPIIIa mRNAs were found to be present in K562, CMK and HEL cells, while only HEL cells expressed PF4 or mRNA. These results suggested that megakaryoblastic cell lines could be categorized into two groups, one with the PF4 transcript and the other without it. PF4 mRNA was present in the cells obtained from one Down's syndrome patient with transient myeloproliferative disorder and in one patient with primary myelofibrosis and megakaryoblastosis. On the other hand, one patient with acute megakaryoblastic leukemia transformed from refractory anemia had a poor prognosis with megakaryoblastic leukemia cells which expressed no PF4 mRNA. These observations suggested that the expression of PF4 mRNA in peripheral blood megakaryoblasts may indicate the absence of a true leukemic process.

Aged↗
PubMed1991

Detection of flaviviruses by reverse-transcriptase polymerase chain reaction.

RNA sequences of five flaviviruses were detected by a modified polymerase chain reaction (PCR) that incorporated a reverse transcriptase and RNase inhibitor. Oligonucleotide primer pairs were synthesized to amplify sequences from St. Louis encephalitis (SLE), Japanese encephalitis (JBE), yellow fever (YF), dengue 2 (DEN-2), and dengue 4 (DEN-4) viruses. The amplified products were visualized as bands of appropriate size on ethidium bromide-stained agarose gels. The identity of these products was confirmed by restriction endonuclease cleavage to generate fragments of predicted lengths. The reverse-transcriptase PCR (RT-PCR) successfully amplified flavivirus sequences from cell cultures, frozen brain tissue, and formalin-fixed, paraffin-embedded brain tissue. The reactions were highly specific, and the method compared favorably to two conventional assays of viral infectivity. RT-PCR followed by PCR with nesting primers (N-PCR) was 1,000-fold more sensitive in detecting virus than classical infectivity titration by intracerebral inoculation of suckling mice and nearly 1,000-fold more sensitive than amplification of virus in cell culture followed by inoculation of mice.

Aedes↗
PubMed1992

Bone marrow stromal fibroblasts secrete interleukin-6 and granulocyte-macrophage colony-stimulating factor in the absence of inflammatory stimulation: demonstration by serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction.

Bone marrow (BM) stromal fibroblasts produce hematopoietic growth factors (HGFs) in response to inflammatory mediators such as tumor necrosis factor-alpha or interleukin-1 alpha (IL-1 alpha). In the absence of such inflammatory stimuli, production of HGFs by BM stromal cells has been problematic and controversial. In vivo, however, basal hematopoiesis maintains blood counts within a normal homeostatic range even in the absence of inflammation, and HGFs are required for progenitor cell differentiation in vitro. To better ascertain the contribution of BM stromal fibroblasts to basal hematopoiesis, we therefore studied HGF production in quiescent BM stromal fibroblasts by three sensitive assays: serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction. Stromal fibroblasts were cultured in the presence or absence of normal human serum to determine if serum factor(s) present in the noninflammatory (basal) state induce secretion of HGFs. Human serum was found to induce or enhance transcription and secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF) and enhance secretion of constitutively expressed IL-6. In contrast, no secretion of either granulocyte-CSF (G-CSF) or IL-3 was found. These data indicate that factors in normal human serum are active in enhancing GM-CSF and IL-6 production by stromal fibroblasts and suggest that these growth factors contribute to the maintainance of normal, basal hematopoiesis in vivo.

Adult↗
PubMed1992

Studies on basic fibroblast growth factor (FGF-beta) gene expression in the rat and pig ovary using in situ hybridization and quantitative reverse transcriptase--polymerase chain reaction techniques.

In order to gain further understanding of the physiology of basic fibroblast growth factor (FGF-beta) in the mammalian reproductive tract, the expression of FGF-beta mRNA in the rat and porcine ovary has been examined by in situ hybridization and quantitative reverse transcriptase-polymerase chain reaction techniques during different stages of the estrus cycle. The results confirm that an increase in FGF-beta mRNA levels occurs over the course of the estrus cycle. No FGF-beta gene expression was detected during diestrus, the non-hormonal phase of the cycle, or at the early proestrus stage of the cycle. During late proestrus and estrus, FGF-beta mRNA was predominantly localized to granulosa cells of the dominant follicles, and to a lesser extent, to secondary antral follicles not committed to ovulation. These cells also expressed FGF-beta mRNA during this phase of follicular development, albeit in low abundance. During metestrus, after ovulation, in the newly formed corpora lutea FGF-beta mRNA levels were maximal, however on entering the next cycle commencing at diestrus, no FGF-beta mRNA was observed in the degenerating corpora lutea. These results indicate that expression of the FGF-beta gene is differentially regulated during the estrus cycle. The biological significance of this expression and the potential role of FGF-beta in local intra-ovarian regulation of the repetitive cycles of follicular differentiation, proliferation and maturation associated with ovarian revascularization are discussed.

Animals↗
PubMed1992

Molecular identification of the liver- and the heart-type fatty acid-binding proteins in human and rat kidney. Use of the reverse transcriptase polymerase chain reaction.

The cDNAs of two types of fatty acid-binding protein (FABP) present in human kidney, previously described as types A and B, were isolated using reverse transcriptase-PCR (RT-PCR) with human kidney mRNA and various sets of primers. The cDNA fragments were cloned and sequenced. Renal FABP type A and B cDNAs appeared to be completely identical to human liver- and heart-type FABP cDNAs respectively. In the second part of this study we demonstrated the presence of liver-type FABP in rat kidney by chromatography, e.l.i.s.a. and immunocytochemistry. The ratio and cellular distribution of the two FABP types varies markedly in human and rat kidney. Using RT-PCR we were also able to prepare and identify liver- and heart-type FABP cDNAs with mRNA from both male and female rat kidney.

Animals↗
PubMed1992

[Detection of minimal residual disease using reverse transcriptase polymerase chain reaction technique].

Polymerase chain reaction (PCR) is a highly sensitive technique to detect minimal residual disease (MRD) of hematological malignancy by amplifying tumor specific nucleotide sequences. When breakpoint is located over large lesions of genomic DNA, like t(9;22) leukemia, PCR amplifying cDNA of chimeric mRNA, called reverse transcriptase PCR (RT-PCR), can be utilized. We applied this method for the detection of MRD in patients with t(1; 19) acute lymphoblastic leukemia. RT-PCR detection of MRD in patients with leukemia might be useful for estimating of the depth of remission, for disclosing preclinical relapse, and for evaluating the efficacy of in vitro purging in autologous bone marrow transplantation.

DNA, Neoplasm↗
PubMed1992

Detection of rotaviruses in the day care environment by reverse transcriptase polymerase chain reaction.

Group A rotavirus is an important cause of morbidity among infants and toddlers in day care centers. Transmission by the fecal-oral route is well established, but fomites and environmental surfaces may also play an important role in transmission. A highly sensitive polymerase chain reaction (PCR) assay was used to detect rotavirus RNA in day care environments. Areas sampled included floors, diaper change areas, toy balls, and other surfaces. In two centers undergoing outbreaks of rotavirus, 7 (39%) of 18 toy balls had detectable rotavirus as did 8 (21%) of 39 swabs from environmental surfaces. By comparison, only 1 (5%) of 21 toy balls and 1 (2%) of 44 environmental surface swabs had detectable rotavirus in centers without rotavirus outbreaks (P = .0001). Thus, rotaviruses are highly prevalent in day care centers during outbreaks of diarrhea. The monitoring of environments by sensitive nucleic acid amplification techniques may lead to strategies for the diminution of disease transmission within the day care environment.

Base Sequence↗
PubMed1992

Detection of Norwalk virus in stool specimens by reverse transcriptase-polymerase chain reaction and nonradioactive oligoprobes.

A reverse transcriptase (RT)-polymerase chain reaction (PCR)-oligoprobe (OP), or RT-PCR-OP, method was developed for the detection of the Norwalk virus, which causes acute, epidemic gastroenteritis, in stool specimens. The Norwalk virus genome regions encoding the following two proteins were amplified by RT-PCR: the RNA polymerase (260-bp product) and a putative immunogenic protein (224-bp product). The resulting DNA fragments (amplicons) were hybridized to a digoxigenin-labeled internal OP specific to each amplicon. The detection limit of Norwalk virus, as determined by the endpoint of RT-PCR amplification for serially diluted, positive stool specimens, was similar to the actual virion titer as estimated by electron microscopy and at least 100-fold greater than the titer determined by radioimmunoassay (RIA). The RT-PCR-OP assay was specific for Norwalk virus and negative for other enteric viruses, including human and animal caliciviruses, hepatitis E virus, Snow Mountain agent, astroviruses, 16 human enteroviruses, and 5 human rotaviruses. Components of fecal specimens that interfere with RT-PCR were removed successfully by Sephadex G-200 gel chromatography. Of 20 stool specimens from human volunteers that were positive for Norwalk virus by RIA, a specific RT-PCR-OP result was obtained in 95% (19 of 20) of the samples by using the immunogenic protein primers and 75% (15 of 20) by using the polymerase primers. Twenty-six stool specimens from asymptomatic children and adults were negative by the Norwalk virus RT-PCR-OP. RT-PCR-OP detected Norwalk virus in the 4 of 21 coded fecal specimens that were also positive by enzyme immunoassay. Two samples that were positive by RIA or enzyme immunoassay were negative by RT-PCR, perhaps because viral RNA was not present or RT-PCR inhibitors were not adequately removed.

Adult↗
PubMed1990

Removal of inhibitory substances from human fecal specimens for detection of group A rotaviruses by reverse transcriptase and polymerase chain reactions.

A method was developed for the purification of rotavirus RNA from fecal extracts in order to permit the sensitive identification of group A rotavirus in fecal specimens by the polymerase chain reaction. Sequential reactions with reverse transcriptase and Taq polymerase with directed primers from rotavirus gene 6 yielded characteristic 259-base-pair fragments that were then visualized by silver stain on a polyacrylamide gel. As few as 500 genomic copies of purified rotavirus RNA could be detected in this manner. However, when the method was applied to fecal samples with added rotavirus virions, inhibition was noted in many of the fecal extracts which were tested. The inhibition could be reversed by dilution of the fecal extract, but sensitivity was also reduced by a corresponding dilutional factor. The inhibition was quantitatively removed by an added step in the extraction process that utilized chromatographic cellulose fiber powder (CF11 powder) to purify the rotavirus RNA during a series of rapid washing and elution steps. After CF11 purification, rotavirus RNA could be detected in experimental fecal samples at dilutions 1,000- to 10,000-fold beyond the detection limits of standard techniques such as enzyme immunoassay and the direct visualization of RNA following polyacrylamide gel electrophoresis. Furthermore, following purification by CF11, rotavirus RNA could be detected in all of seven enzyme-linked immunosorbent assay-positive fecal samples obtained from a child with rotavirus gastroenteritis; when CF11 purification was not performed, rotavirus RNA could be detected in only four of these samples, even after the removal of inhibitors by dilution of the extracts. Large-scale identification of rotavirus in fecal specimens may be possible by use of CF11 purification of viral RNA prior to sequential reactions with reverse transcriptase and Taq polymerase in a modified polymerase chain reaction.

Feces↗
PubMedDate not supplied

Comparative evaluation of bovine immunodeficiency-like virus infection by reverse transcriptase and polymerase chain reaction.

Infection of embryonic bovine lung (EBL) cells by bovine immunodeficiency-like virus (BIV) were monitored by reverse transcriptase (RT), syncytia formation and polymerase chain reaction (PCR). Infection can be detected by PCR at 24 h while the presence of syncytia and RT were not detected until much later. The detection of BIV RT can be optimized by changing the pH and salt conditions. The enzyme is very sensitive to changes in pH but can tolerate a wider range of salt and MgCl2 concentrations. Infection of primary human cell cultures by BIV was monitored by both PCR and RT. No active infection of human cells were detectable.

Animals↗
PubMed1992

Detection of retinoic acid receptor mRNA in rat tissues by reverse transcriptase-polymerase chain reaction.

The presence of retinoic acid receptor (RAR) alpha, beta and gamma mRNA was examined in 16 different kinds of rat tissue using the highly sensitive reverse transcriptase-polymerase chain reaction technique. The data demonstrated that each tissue expressed at least two types of RAR mRNA. Among the three types of RAR mRNA, RAR alpha was widely expressed in all types of organ and was the dominant form expressed in the gastrointestinal tract. RAR beta mRNA was not present in the intestine and spleen. In addition, RAR beta mRNA levels were high in the heart, lung, brain, testis and epididymis. RAR gamma mRNA was abundant in both male and female reproductive systems, as well as epidermal tissues. The prevalence of each RAR mRNA in the tissues suggests the diverse biological roles of these receptors.

Animals↗
PubMed1992

Rapid detection and typing of dengue viruses from clinical samples by using reverse transcriptase-polymerase chain reaction.

We report on the development and application of a rapid assay for detecting and typing dengue viruses. Oligonucleotide consensus primers were designed to anneal to any of the four dengue virus types and amplify a 511-bp product in a reverse transcriptase-polymerase chain reaction (PCR). First, we produced a cDNA copy of a portion of the viral genome in a reverse transcriptase reaction in the presence of primer D2 and then carried out a standard PCR (35 cycles of heat denaturation, annealing, and primer extension) with the addition of primer D1. The resulting double-stranded DNA product of the RT-PCR was typed by two methods: dot blot hybridization of the 511-bp amplified product to dengue virus type-specific probes or a second round of PCR amplification (nested PCR) with type-specific primers, yielding DNA products the unique sizes of which were diagnostic for each dengue virus serotype. The accumulated data demonstrated that dengue viruses can be accurately detected and typed from viremic human serum samples.

Animals↗
PubMed1992

[Detection of estrogen receptor (ER) mRNA by use of reverse transcriptase-polymerase chain reaction (RT-PCR) assay; comparison with dextran coated charcoal (DCC) assay and immunocytochemical assay].

A new method for estrogen receptor (ER) mRNA was performed on 33 human breast tumors, using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay by the method of Fuqua et al. In a preliminary experiment using the MCF-7 breast tumor cell line, ER/beta-actin ratio was almost same. ER protein was estimated by a dextran coated charcoal (DCC) assay and by an ER-immunocytochemical (ER-ICA) assay using a specific monoclonal antibody. We found RT-PCR assay correlates with ER-ICA assay (r = 0.664, p less than 0.01), whereas no significant correlation was seen between RT-PCR assay and DCC assay. These results suggests that RT-PCR assay is suitable for detection of ER from small amounts of tissue.

Blotting, Southern↗
PubMed1991

Identification of mRNA for epidermal growth factor and transforming growth factor-alpha present in low copy number in human endometrium and decidua using reverse transcriptase-polymerase chain reaction.

The presence of mRNA for epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) was demonstrated in small fragments of human endometrium and decidua by use of the technique of reverse transcriptase-polymerase chain reaction with nested oligonucleotide primers. The presence of mRNA encoding EGF and TGF alpha has not been shown in human endometrium previously. Other studies using conventional techniques, such as Northern blot or in-situ hybridization, showed the presence in low copy number of EGF but not TGF alpha in murine endometrium. Messenger RNA for EGF was not present in peripheral leukocytes or platelets, suggesting an endometrial source for the message. Messenger RNA for TGF alpha was found in these blood components, thus preventing confirmation of the source of TGF alpha mRNA.

Base Sequence↗
PubMed1991

[Analysis of human papillomavirus type 16 E6/E7 mRNA in cervical cancers and precancerous lesions by means of the polymerase chain reaction with reverse transcriptase reaction].

We analyzed HPV-16 E6/E7 mRNA in human uterine cervical carcinomas and cervical intraepithelial neoplasias (CINs) by polymerase chain reaction (PCR) with reverse transcription (RT-PCR). Simultaneously total RNA and DNA were extracted from 6 cervical carcinomas, 14 CINs and 2 normal cervical tissues by the guanidium isothiocyanate/CsCl method. HPV-16 DNA was detected in 3 cervical carcinomas and 6 CINs. HPV-16 E6/E7 transcripts were detected in all HPV-16 DNA positive cervical carcinomas and CINs. In 2 cervical carcinomas and 5 CINs, 2 spliced E6 mRNA (E6*I and E6*II) and full length E6 mRNA were detected. In one cervical carcinoma and in one CIN, only full length E6-E7 mRNA was detected. Sequence analysis of cloned PCR products showed that both transcripts were generated by splicing out an intron in E6, from nucleotides (nt) 226 to 409 in E6*I and from nt 226 to 526 in E6*II. There was no significance difference in HPV-16 E6/E7 mRNA patterns between cervical carcinomas and CINs. This sensitive RT-PCR technique was available for analysis of HPV-16 mRNA in the small specimens.

Carcinoma, Squamous Cell↗