A Simple Method for Elimination of False Positive Results in RT-PCR

Martel, Fatima,Grundemann, Dirk,Schomig, Edgar 생화학분자생물학회 1997 BMB Reports Vol.35 No.2

Discrimination between the amplification of mRNA and contaminating genomic DNA is a common problem when performing a reverse transcriptase-polymerase chain reaction (RT-PCR). Even after treatment of the samples with DNAse, it is possible that negative controls (samples in which no reverse transcriptase was added) will give positive results. This indicates that there was amplification of DNA, which was not generated during the reverse transcriptase step. The possibility exists that Taq DNA polymerase acts as a reverse transcriptase, generating cDNA from RNA during the PCR step. In order to test this hypothesis, we incubated samples with a DNAse-free RNAse after the cDNA synthesis. Comparison of the results that were obtained from these samples (incubated with or without DNAse-free RNAse) confirms that the reverse transcriptase activity of Taq DNA polymerase I is a possible source of false positive results when performing RT-PCR from intronless genes. Moreover, we describe here a simple and rapid method to overcome the false positive results that originate by this activity of Taq polymerase.

A Simple Method for Elimination of False Positive Results in RT-PCR

Martel, Fatima,Grundemann, Dirk,Schomig, Edgar Korean Society for Biochemistry and Molecular Biol 2002 Journal of biochemistry and molecular biology Vol.35 No.2

Discrimination between the amplification of mRNA and contaminating genomic DNA is a common problem when performing a reverse transcriptase-polymerase chain reaction (RT-PCR). Even after treatment of the samples with DNAse, it is possible that negative controls (samples in which no reverse transcriptase was added) will give positive results. This indicates that there was amplification of DNA, which was not generated during the reverse transcriptase step. The possibility exists that Taq DNA polymerase acts as a reverse transcriptase, generating cDNA from RNA during the PCR step. In order to test this hypothesis, we incubated samples with a DNAse-free RNAse after the cDNA synthesis. Comparison of the results that were obtained from these samples (incubated with or without DNAse-free RNAse) confirms that the reverse transcriptase activity of Taq DNA polymerase I is a possible source of false positive results when performing RT-PCR from intronless genes. Moreover, we describe here a simple and rapid method to overcome the false positive results that originate by this activity of Taq polymerase.

Sulfur Ylide Vinylation of Halides and Mesylates

Le Gall,T.,Martel, J. P.,Harnett, J. J.,Shin,Dong-Soo,Flack, J. R.,Mioskowski, C.,Alcaraz, L. 國立昌原大學校 基礎科學硏究所 1994 基礎科學硏究所論文集 Vol.6 No.-

One-carbon homologation of benzylic, allylic, propargylic and primary halides or mesylates with dimethylsulfonium methylide affords terminal olefins in good to excellent yields.

Boosting Power Generation by Sediment Microbial Fuel Cell in Oil-Contaminated Sediment Amended with Gasoline/Kerosene

Aleman-Gama, Elizabeth,Cornejo-Martell, Alan J.,Kamaraj, Sathish Kumar,Juarez, Katy,Silva-Martinez, Susana,Alvarez-Gallegos, Alberto The Korean Electrochemical Society 2022 Journal of electrochemical science and technology Vol.13 No.2

The high internal resistance (R_int) that develops across the sediment microbial fuel cells (SMFC) limits their power production (~4/10 mW m^-2) that can be recovered from an initial oil-contaminated sediment (OCS). In the anolyte, R_int is related to poor biodegradation activity, quality and quantity of contaminant content in the sediment and anode material. While on the catholyte, R_int depends on the properties of the catholyte, the oxygen reduction reaction (ORR), and the cathode material. In this work, the main factors limiting the power output of the SMFC have been minimized. The power output of the SMFC was increased (47 times from its initial value, ~4 mW m^-2) minimizing the SMFC R_int (28 times from its initial value, 5000 ohms), following the main modifications. Anolyte: the initial OCS was amended with several amounts of gasoline and kerosene. The best anaerobic microbial activity of indigenous populations was better adapted (without more culture media) to 3 g of kerosene. Catholyte: ORR was catalyzed in birnessite/carbon fabric (CF)-cathode at pH 2, 0.8M Na₂SO₄. At the class level, the main microbial groups (Gammaproteobacteria, Coriobacteriia, Actinobacteria, Alphaproteobacteria) with electroactive members were found at C-anode and were associated with the high-power densities obtained. Gasoline is more difficult to biodegrade than kerosene. However, in both cases, SMFC biodegradation activity and power output are increased when ORR is performed on birnessite/CF in 0.8 M Na₂SO₄ at pH 2. The work discussed here can focus on bioremediation (in heavy OCS) or energy production in future work.

Aculturación Y Estilos de Vida de Los Migrantes Mexicanos en Estados Unidos

Sagrario Garay Villegas,Juan Martell Muñoz 부산외국어대학교 이베로아메리카연구소 2015 이베로아메리카 Vol.17 No.1

El flujo migratorio de mexicanos que se dirigen a Estados Unidos es un hecho conocido y documentado desde hace varias décadas. Las variaciones en las características de los migrantes y en su monto hace que cada vez se torne más complejo el estudio de este fenómeno, y al mismo tiempo permite que se deriven una serie de temas asociados con el desplazamiento, la adaptación de los migrantes en el país receptor y las implicaciones que se originan tanto en los migrantes como en su entorno. En particular en este artículo se tiene como objetivo principal mostrar el papel de la aculturación (vista a través del dominio del idioma inglés) en los estilos de vida de los migrantes mexicanos en Estados Unidos. Para llevar a cabo lo anterior se hace una discusión amplia sobre los procesos migratorios, la aculturación y los estilos de vida de los migrantes; además a partir de la Hispanic Health Care Survey 2007, se realiza una aproximación empírica de los estilos de vida de los migrantes mexicanos más y menos aculturizados. Palabras Clave: Migrantes, Aculturación, Estilos de Vida y Salud. The flow of Mexicans who go to the United States has been studied for several decades. The changes in the amount and the characteristics of the migrants makes more and more complex the study of this phenomenon and, at the same time, it allows to derive a number of issues associated with their displacement, the adaptation of migrants in the host country and the implications that arise both migrants and their context. In particular in this article is aimed to show the role of acculturation (view through the dominance of the English language) on lifestyles of Mexican migrants in the United States. To carry out the above we present a wide discussion on migratory processes, acculturation and the lifestyles of migrants. In addition, we use as source of data the Hispanic Health Care Survey 2007, like an empirical approximation to show the relation between acculturation, lifestyles and health of the Mexican migrants in United States. Key Words: Migrants, Acculturation, Lifestyles and Health

Motor-based interventions improve language outcomes in children with autism: a systematic review

Christina E. Odeh,Rebecca Martell,Sarah Griffin,Erik R. Johnson,Allison L. Gladfelter 한국언어재활사협회 2020 Clinical Archives of Communication Disorders Vol.5 No.1

Purpose: Children with autism spectrum disorder (ASD) show motor deficits in addition to the social communication and repetitive behaviors characteristic of the disorder. However, these deficits have traditionally been targeted independently during intervention. The primary purpose of this systematic review was to determine whether interventions with motor targets improved language or social communication outcomes in individuals with ASD. Methods: Five databases were searched using the following terms:autis*, asper*, motor*, therap*, interven*, and treat*. After eliminating irrelevant and duplicate articles, 74 articles underwent full text review to determine whether they met the inclusionary/exclusionary criteria. The 15 included articles were then checked for inter-rater reliability and appraised for the quality of their research design, treatment fidelity, and interobserver agreement. Following the quality appraisals, 13 included articles were analyzed for final data extraction. Results: Of the 13 included studies, 12 showed at least one increased language outcome, seven demonstrated at least one increased motor outcome, and one revealed no significant change in either language or motor outcomes. Conclusions: Consistent with previous research, many of the children with ASD presented weaknesses in both motor and language skills. In most studies, the motor-based interventions led to an increase in language skills, indicating language and motor system interdependence. These findings also suggest that co-treatment between physical therapists and occupational therapists alongside speech-language pathologists may be warranted when working with children with ASD.

Optically stimulated second-order optical susceptibilities of self-assembled multi-layers film samples

I.V. Kityk,H. Nguyen Cong,D. Martel,M. Piasecki,K. Ozga,J. Ebothe 한국물리학회 2009 Current Applied Physics Vol.9 No.5

In the present paper for the first time we study the influence of simultaneous polarized optical treatment (10 ns Nd: YAG lasers with power density 0.6 GW/㎠) together with electrostatic dc electric field (up to 8 kV/cm) on self-assembled multi-layer films samples. The second-order optical susceptibility (SOS) achieves the maximal values after one minute simultaneous dc-electrical-optical treatment. Further treatment will not enhance the values and even leads to the decrease of SOS. The independent measurement of the local temperature shows that local heating do not excess 8.6 K.

Characteristics of Thiamine Uptake by the BeWo Human Trophoblast Cell Line

Keating, Elisa,Lemos, Clara,Azevedo, Isabel,Martel, Fatima Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.4

Little is known concerning the mechanisms responsible for the transplacental transfer of thiamine. So, the aim of this work was to characterize the placental uptake of thiamine from the maternal circulation, by determining the characteristics of $^3H$-thiamine uptake by a human trophoblast cell line (BeWo). Uptake of $^3H$-thiamine (50-100 nM) by BeWo cells was: 1) temperature-dependent and energy-independent; 2) pH-dependent (uptake increased as the extracellular medium pH decreased); 3) $Na^+$-dependent and $Cl^-$-independent; 4) not inhibited by the thiamine structural analogs amprolium, oxythiamine and thiamine pyrophosphate; 5) inhibited by the unrelated organic cations guanidine, N-methylnicotinamide, tetraethylammonium, clonidine and cimetidine; 6) inhibited by the organic cation serotonin, and by two selective inhibitors of the serotonin plasmalemmal transporter (hSERT), fluoxetine and desipramine. We conclude that $^3H$-thiamine uptake by BeWo cells seems to occur through a process distinct from thiamine transporter-1 (hThTr-1) and thiamine transporter-2 (hThTr-2). Rather, it seems to involve hSERT. Moreover, chronic (48 h) exposure of cells to caffeine ($1\;{\mu}M$) stimulated and chronic exposure to xanthohumol and iso-xanthohumol (1 and $0.1\;{\mu}M$, respectively) inhibited $^3H$-thiamine uptake, these effects being not mediated through modulation of the expression levels of either hThTr-1 or hSERT mRNA.

Concordance between tuberculin skin test and interferon-gamma release assay for latent tuberculosis screening in inflammatory bowel disease

( Saad Alrajhi ),( Pascale Germain ),( Myriam Martel ),( Peter Lakatos ),( Talat Bessissow ),( Talal Al-taweel ),( Waqqas Afif ) 대한장연구학회 2020 Intestinal Research Vol.18 No.3

Background/Aims: Latent tuberculosis screening is mandatory prior to initiating anti-tumor necrosis factor (anti-TNF) medications. Guidelines recommend interferon-gamma release assays (IGRA) as first line screening method for the general population. Studies provided conflicting evidence on IGRA and tuberculin skin test (TST) performance in inflammatory bowel disease (IBD) patients. We assessed test concordance and the effects of immunosuppression on their performance in IBD patients. Methods: We searched MEDLINE, Embase and Cochrane databases (2011-2018) for studies testing TST and IGRA in IBD. Primary outcome was TST and IGRA concordance. Secondary outcomes were effects of immunosuppressive therapy on performance. Immunosuppression defined as either steroids, thiopurine, methotrexate or cyclosporine use. We used the pooled random effects model to adjust for heterogeneity analyzed using (I2-Q statistics). We compared the fixed model to exclude smaller study effects. Results: Sixteen studies (2,488 patients) were included. Pooled TST and IGRA concordance was 85% (95% confidence interval [CI], 81%-88%; P=0.01). Effects of immunosuppression were reported in 8 studies (814 patients). The odds ratio of testing positive by IGRA decreased to 0.57 if immunosuppressed (95% CI, 0.31-1.03; P=0.06). The odds ratio of testing positive by TST if immunosuppressed was 1.14 (95% CI, 0.61-2.12; P=0.69). The fixed model yielded similar results, however the negative effect of immunosuppression on IGRA reached statistical significance (P=0.01). Conclusions: While concordance was 85% between TST and IGRA, the performance of IGRA seems to be negatively affected by immunosuppression. Given the importance of detecting latent tuberculosis prior to anti-TNF initiation, further randomized controlled trials comparing the performance of TST and IGRA in IBD patients are needed. (Intest Res 2020;18:306-314)

Effects of CO2 enrichment, LED inter-lighting, and high plant density on growth of Nicotiana benthamiana used as a host to express influenza virus hemagglutinin H1

Lingling Shang,Linda Gaudreau,Michèle Martel,Dominique Michaud,Steeve Pepin,André Gosselin 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.5

Plants are being recognized as promising hosts for molecular farming and several molecular tools have been developed over the last two decades to optimize recombinant protein yields. However, the effects of basic growth factors on protein yield have been much less studied. Here, we investigated the effects of supplemental light emitting diode (LED) inter-lighting, CO2enrichment, and plant density on growth and recombinant protein yield of Nicotiana benthamiana used as a host to express the vaccine antigen influenza virus hemagglutinin H1. LED inter-lighting improved plant growth and recombinant protein yield on a per-plant basis. CO2 enrichment also enhanced plant growth, but its effect on recombinant protein yield was not significant. By comparison, high plant density decreased recombinant protein production per plant, mainly because of its negative impact on protein accumulation on a per-plant basis. On a whole-crop area basis, supplemental lighting, CO2 enrichment, and high plant density improved plant growth, while only LED inter-lighting and high plant density positively impacted recombinant protein yield. We suggest that LED inter-lighting and an elevated plant density should be used to maximize H1 antigen yield in large-scale protein production systems using N. benthamiana.