جستجوی مقالات مرتبط با کلیدواژه « time rt » در نشریات گروه « پزشکی »

Coronaviruses (CoVs) are large ribonucleic acid (RNA) viruses causing primarily respiratory disease in humans. A novel human coronavirus, subsequently named middle east respiratory syndrome coronavirus (MERS-CoV), was first reported in Saudi Arabia in September of 2012. With increasing numbers of infections and deaths from MERS-CoV, development of a rapid and reliable kit was crucial to prevent further spread of MERS-CoV.
In this study, we present two real-time reverse-transcription polymerase chain reaction (rRT-PCR) assays for in-house rapid and sensitive diagnostic testing of MERS-CoV, detecting the regions upstream of the envelope gene (upE) and open reading frame (ORF) 1b, respectively, for initial screening and final confirmation of MERS-CoV infection, as recommended by the world health organization (WHO).
In this experimental study, acquiring patient samples was difficult; thus, according to WHO recommendations and standard protocols, we synthesized RNA sequences of upE and ORF1b genes as the template signatures and TaqMan based-diagnostic rRT-PCR assays were carried out using these synthetic genes for detection of MERS-CoV. In this research, we also inaugurated a cell-free system to transcribe these RNA sequences using the DNA templates synthesized.
The upE and ORF1b based one-step rRT-PCR assays were optimized by testing several times via different synthetic RNAs, and validation results were highly successful. The sensitivity obtained for upE was fewer than ten copies of RNA template per reaction and for ORF1b was 50 or fewer copies per reaction.
This study showed that the developed rRT-PCR assays are rapid, reliable, reproducible, specific, sensitive, and simple tools for detection of MERS-CoV. Finally, a kit consisting of two assay signatures and controls was assembled, which can be distributed to public health laboratories in Iran to support international MERS-CoV surveillance and public health response.

The hippocampus is a tiny nub in the mammalian brain that is involved in forming, organizing, and storing memories. Global cerebral ischemia (GCI) and reperfusion induced apoptosis lead to cell injury and death. FK-506 is a strong immunosuppressant drug that has neuroprotective effects on the hypoxic-ischemic effects of brain damage. BAD and Bcl-xL are pro-apoptotic and anti-apoptotic genes, respectively. These genes belong to The B-cell lymphoma-2 (Bcl-2) family.. In this study, we assessed the neurotrophic properties of FK-506 on expression of the BAD and Bcl-xL genes in the hippocampus following global ischemia and reperfusion.. In the present experimental study, adult male Wistar rats were obtained and housed under standard conditions in the Tehran University of Medical Science in Iran. Rats were equally distributed in groups of three among the following groups: normal control, treated-1 (ischemia/reperfusion), and treated-2 (ischemia/reperfusion followed by FK-506). Global ischemia was induced for animals in the treated-1 and treated-2 groups. In treated-2, two doses of FK-506 were injected: one dose as an IV injection immediately after reperfusion and another as an intra-peritoneal (IP) injection after 48 hours. Then, the hippocampus tissue was removed after anaesthetizing the rats. RNA was isolated, cDNA was synthesized, and real-time PCR was performed. Finally, the obtained data were analyzed statistically (P value 0.05).. The quantitative results of real-time PCR show that the mRNA expression ratio of Bcl-xL down-regulated was 0.75 ± 0.06 in the ischemia/reperfusion group versus 1.57 ± 0.09 in the control group (P value < 0.001), whereas Bcl-xL gene expression was greater in the ischemia/reperfusion +FK506 group (1.93 ± 0.15) than in the ischemia/reperfusion group. Moreover, the mRNA expression ratio of BAD up-regulated in the ischemia/reperfusion + FK506 group was 3.65 ± 0.49 compared to Normal control (1.39 ± 0.09) and Ischemia/reperfusion + FK506 was 1.09 ± 0.20 (P value < 0.001).. The analysis of the pro-apoptotic gene to anti-apoptotic gene expression ratio (BAD /Bcl-xL) confirmed that expression of the pro-apoptotic gene significantly decreased (P value 0.001) under the ischemia/reperfusion condition. In contrast, the expression of the anti-apoptotic gene increased after administration of FK-506 (P value 0.001)..

Influenza A virus is now considered to be widespread in poultry and has demonstrated the ability to infect humans in Iran. For laboratory diagnosis of these respiratory viruses, it is essential to have rapid methods, able to detect viruses in early stages of the infection in clinical specimens. The real-time reverse-transcription polymerase chain reaction n (rRT-PCR) assay has been established as a standard method for Influenza virus type A diagnosis inpatients. In this study, we evaluated a single-tube rRT-PCR assay, targeting to the highly conserved region of matrix (M) gene for detection of the virus. In this experimental study, after preparation of 100throat mucus samples, respective RNA was extracted from the virus by using viral RNA extraction kit. Two specific primers were synthesized, based on the conserved region of Influenza type AM-gene and a home-brewed one-step SYBR Green based rRT-PCR was developed and evaluated for detection of Influenza type A infection in the viral samples, on the basis of melting curve analysis. The presence of M-gene in RNAs, extracted from 53viralsamples, was confirmed by this single-tube rRT-PCR assay, and after 45 amplification cycles, the melting curve analysis revealed the melting temperature (Tm) of 83.2 ± 0.5°C for various viral samples, quite different from that of primer-dimers and the positive samples showed only a small variation in parameters. This study showed that the developed one-step rRT-PCR assay is the proper molecular method for rapid and accurate diagnosis of Influenza A by detection of M-protein encoding gene.

The polyphenol silybin has anti-oxidant and anti-cancer properties. The poor bioavailability of some polyphenols (flavonoids, and terpenoids) can be improved by binding them to phosphatidylcholine (phytosome technology). Many studies have focused on the most common phytosome, silybin-phosphatidylcholine, particularly for its hepatoprotective effects. However, in recent years, studies have also been conducted to determine its anti-cancer effect. Considering that the serum starvation should not be used for studies that are not focused on cell cycle arrest, we studied the effect of silybin-phosphatidylcholine from Silybin Advanced™ in 1:2 ratio (one part silybin bound to two parts phosphatidylcholine) on HER2 gene expression on the SKBR3 breast cancer cell line which were cultured in complete medium (not serum deprivation). The results were compared with our previous study of silybin on HER2 expression on SKBR3 cells. An MTT test was used to determine concentrations for cell treatment, and the gene expression was defined by real-time RT-PCR.Outcomes showed significant concentration- and time-dependent cell growth inhibitory effects of silybin, and silybin-phosphatidylcholine and HER2 down regulation on SKBR3 cells. Silybin-phosphatidylcholine concentrations had a much larger inhibitory and HER2 down regulate effect on cell growth than the same silybin concentrations on SKBR3 cells.

Leishmaniasis is a parasitic disease caused by different species of Leishma­nia parasites with a wide range of clinical manifestations. Antimonial com­pounds such as meglumine antimoniate (glucantime) are the first line drugs for the treat­ment of leishmaniasis. However, according to reports of the drug resistance of parasites, the efficacy of antimonial compounds is low. The ATP-binding cassette (ABC) proteins are present in all organisms and mediate the transport of vital elements through biological membranes. One of the important mechanisms of resistance in Leishma­nia parasites is the overexpression of ABC efflux pumps. P-glycoprotein A (pgpA) is a related gene for ABC transporter in Leishmania species. The aim of this study was to compare the pgpA expression in laboratory-induced resistant L. major (MRHO/IR/75/ER) and sensitive parasites. RNA extraction of promastigotes of sensitive and resistant clones was per­formed and total RNA was reverse transcribed. The real-time quantitative polymerase chain reaction (PCR) was used to assess RNA expression profiles and the expression levels were calculated using 2-ΔCt method. The mean expression level of pgpA mRNA was 2.70 ± 0.51 in in sensitive Leishmania clone and 6.08 ± 1.50 in resistant Leishmania clone (P = 0.021). The expression of pgpA gene in resistant strains of L. major was almost fivefold higher than those in susceptible strains. Therefore, this can be used in field isolates, i.e. overexpression of the gene can prove resistance in wild type field isolates.

Pentavalent antimonials are the first line drugs for the treatment of leishmaniasis. Unresponsiveness of Leishmania spp. to antimonial drugs is a serious problem in some endemic areas. Investigations on molecular mechanisms involved in drug resistance are essential for monitoring and managing of the disease. Calcineu­rin is an essential protein phosphatase for number of signal transduction pathways in eukaryotic cells and it has a mediated role in apoptosis. This study aimed to determine of biomarker(s) in Glucantime® resiatance strain of L. infan­tum. We used cDNA amplified fragment length polymorphism (cDNA-AFLP) and real time-RT PCR assays to compare gene expression profiles at the mRNA levels in resistant and susceptible L. infantum field isolates. The cDNA-AFLP results showed downlegulation of calcineurin in resis­tant isolate in comparison with susceptible one. Significant downregulation of calcineu­rin (0.42 fold) (P<0.05) was found in resistant isolate compared to suscepti­ble one by Real time-RT PCR. This is the first report of calcineurin implication in Glucantime® drug resistance of field (natural) isolate of L. infantum. Downregulation of calcineurin could protect parasites from antimonial-induced apoptosis.

In this study we investigated the expression of GABAA receptor subunits during brain development. These receptors may change in the embryonic chick forebrain.Materials and Methodes:The expression levels of four types of GABAA receptor gamma subunits (γ1, γ2, γ3 and γ4) were quantified in the embryonic chick forebrain at 32 hr, 3, 7, 14, and 20 days of incubation and day one after hatching. The expression level of mRNA in the forebrain of embryonic chicken was measured using real-time RT-PCR. The expression level of each subunit increased gradually with development and reached a plateau on 20th day of embryonic development. A reduction was observed on day one after hatching in all gamma subunits.This may explain the different physiological and pharmacological function of GABA receptor gamma subunits before and after hatching.