Rodrigues M.F.S.D.,University of Sao Paulo |
De Oliveira Rodini C.,University of Sao Paulo |
De Aquino Xavier F.C.,Federal University of Bahia |
Paiva K.B.,Chemistry Institute |
And 7 more authors.
Medicine (United States) | Year: 2014
Homeobox genes are a family of transcription factors that play a pivotal role in embryogenesis. Prospero homeobox 1 (PROX1) has been shown to function as a tumor suppressor gene or oncogene in various types of cancer, including oral squamous cell carcinoma (OSCC). We have previously identified PROX1 as a downregulated gene in OSCC. The aim of this study is to clarify the underlying mechanism by which PROX1 regulates tumorigenicity of OSCC cells. PROX1 mRNA and protein expression levels were first investigated in 40 samples of OSCC and in nontumor margins. Methylation and amplification analysis was also performed to assess the epigenetic and genetic mechanisms involved in controlling PROX1 expression. OSCC cell line SCC9 was also transfected to stably express the PROX1 gene. Next, SCC9-PROX1-overexpressing cells and controls were subjected to proliferation, differentiation, apoptosis, migration, and invasion assays in vitro. OSCC samples showed reduced PROX1 expression levels compared with nontumor margins. PROX1 amplification was associated with better overall survival. PROX1 overexpression reduces cell proliferation and downregulates cyclin D1. PROX1-overexpressing cells also exhibited reduced CK18 and CK19 expression and transcriptionally altered the expression of WISP3, GATA3, NOTCH1, and E2F1. Our results suggest that PROX1 functions as a tumor suppressor gene in oral carcinogenesis. Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins.
News Article | October 23, 2015
James L. Kinsey, the former head of the Department of Chemistry at MIT and the D. R. Bullard-Welch Foundation Professor of Science Emeritus at Rice University, died unexpectedly on Dec. 20. He was 80. Kinsey was born in Paris, Texas, in 1934. He earned a BA from Rice in 1956 and continued at that institution for graduate studies, earning a PhD in physical chemistry in 1959 under Robert F. Curl, who went on to receive the Nobel Prize in chemistry in 1996. The title of Kinsey’s dissertation was “The Microwave Spectrum of Chlorine Dioxide.” In 1959 and 1960, Kinsey spent one year at the University of Uppsala in Sweden as an NSF Postdoctoral Fellow at the Quantum Chemistry Institute. He then spent a year in the Department of Chemistry at the University of California at Berkeley as a Miller Research Fellow. In 1962, Kinsey was appointed as an assistant professor of chemistry at MIT, where he served for 26 years, rising through the tenure ranks. He succeeded John Deutch, now an Institute Professor, as head of the Department of Chemistry in 1977, and held that position until 1982. “Jim Kinsey mentored me from the time I was a graduate student,” Deutch says. “He tried to teach me group theory and 3j coupling coefficients, but failed. His knowledge and devotion to chemistry was unmatched. Throughout his career, he made great contributions to MIT, Rice, and the Welch Foundation. One of my oldest and trusted friends is gone, and I grieve for the loss.” Kinsey was known for his novel studies of the dynamics of disintegrating molecules using various spectroscopic techniques, including his significant advance of Fourier transform doppler spectroscopy and, with Robert W. Field, the development of stimulated emission pumping. He was also much admired for his leadership skills and his unpretentious disposition. “Jim and I had a wonderful collaboration,” says Field, the Robert T. Haslam and Bradley Dewey Professor of Chemistry. “We were so different in our scientific styles, our relationships with members of our joint research group, and in how we would approach and finish off a problem. … Jim was analytical; I was intuitive. Jim was cautious; I was not. … We created magic between us, and shared the joy of knowing that we had created some new truth.” “Our cross-department collaboration involved two joint PhDs, two [undergraduate researchers], one future Nobel Prize winner, a lot of brown-bag lunches, and the delight of both scientific and personal insights — including that Jim and I shared the same birthday,” says Dave Pritchard, the Cecil and Ida Green Professor of Physics. “I was having lunch with him about a month ago, when — typically — he had to rush off to do something for a former student.” David Jonas PhD '92, a professor of chemistry at the University of Colorado at Boulder, says, “Jim Kinsey was a wonderful co-advisor. I benefited tremendously from his gentle and seemingly effortless approach to resolving contested scientific questions and fondly recall his mischievous sense of humor. I will always remember Jim as a great human being.” Sylvia Ceyer, current head of the Department of Chemistry and the John C. Sheehan Professor of Chemistry, recalls, “Jim was the chemistry department head who hired me as an assistant professor in 1981. From that moment on, Jim became a beloved mentor and friend who selflessly and carefully read and valuably commented on many of my early proposals and papers, even though the subject matter was not centered in his own research interests. I know that I am a much better scientist because of Jim.” She adds, “Jim Kinsey was so incredibly smart, but more importantly, so profoundly wise. He had a knack for quickly spotting the heart of an issue and deftly employing his dry wit to rapidly build a consensus. Listening to the clever repartee of Jim, Bob Silbey, John Deutch, Irwin Oppenheim, and John Waugh is a most cherished MIT memory.” In 1988, Kinsey took early retirement from MIT and returned to Rice, his alma mater, where he served as dean of the Wiess School of Natural Sciences for 10 years. In addition, he served Rice's interim provost from 1993 to 1994. “Jim Kinsey came to Rice with a vision for what we could be, and set about in a determined fashion to bring that view into the reality we see today,” says Kathleen Matthews, who succeeded Kinsey as dean of the Wiess School. “But no discussion of him would ignore his wit and sense of humor.” Kinsey made frequent return visits to MIT while serving as a member of the MIT Chemistry Department Visiting Committee from 1994 to 2006. Kinsey served as chairman of the Scientific Advisory Board of the Robert A. Welch Foundation from 2006 to 2012. He was a member of the National Academy of Sciences and received the E.O. Lawrence Award of the Department of Energy and the Earle K. Plyler Prize of the American Physical Society. He was a fellow of the American Physical Society and of the American Academy of Arts and Sciences. He and Field were honored as mentors of their joint student Yonqin Chen, who received the American Chemical Society’s Nobel Laureate Signature Prize in Graduate Education. There will be a memorial at Rice University in the Keck Lecture Hall (old chemistry lecture hall) on Saturday, Feb. 28, at 2 p.m., with a reception to follow at Brochstein Pavilion.
Carreira A.C.O.,University of Sao Paulo |
Zambuzzi W.F.,Paulista University |
Rossi M.C.,Paulista University |
Filho R.A.,University of Sao Paulo |
And 4 more authors.
Vitamins and Hormones | Year: 2015
Bone morphogenetic proteins (BMPs), glycoproteins secreted by some cells, are members of the TGF-β superfamily that have been implicated in a wide variety of roles. Currently, about 20 different BMPs have been identified and grouped into subfamilies, according to similarities with respect to their amino acid sequences. It has been shown that BMPs are secreted growth factors involved in mesenchymal stem cell differentiation, also being reported to control the differentiation of cancer stem cells. BMPs initiate signaling from the cell surface by binding to two different receptors (R: Type I and II). The heterodimeric formation of type I R and II R may occur before or after BMP binding, inducing signal transduction pathways through SMADs. BMPs may also signal through SMAD-independent pathways via mitogen-activated protein kinases (ERK, p38MAPKs, JNK). BMPs may act in an autocrine or paracrine manner, being regulated by specific antagonists, namely: noggin and chordin. Genetic engineering allows the production of large amounts of BMPs for clinical use, and clinical trials have shown the benefits of FDA-approved recombinant human BMPs 2 and 7. Several materials from synthetic to natural sources have been tested as BMP carriers, ranging from hydroxyapatite, and organic polymers to collagen. Bioactive membranes doped with BMPs are promising options, acting to accelerate and enhance osteointegration. The development of smart materials, mainly based on biopolymers and bone-like calcium phosphates, appears to provide an attractive alternative for delivering BMPs in an adequately controlled fashion. BMPs have revealed a promising future for the fields of Bioengineering and Regenerative Medicine. In this chapter, we review and discuss the data on BMP structure, mechanisms of action, and possible clinical applications. © 2015 Elsevier Inc.
Fischer J.d.S.d.G.,Chemistry Institute |
Fischer J.d.S.d.G.,Scripps Research Institute |
Liao L.,Scripps Research Institute |
Carvalho P.C.,Scripps Research Institute |
And 5 more authors.
Journal of Proteomics | Year: 2010
Perillyl alcohol (POH) is a naturally occurring terpene and a promising chemotherapeutic agent for glioblastoma multiform; yet, little is known about its molecular effects. Here we present results of a semi-quantitative proteomic analysis of A172 cells exposed to POH for different time-periods (1′, 10′, 30′, 60′, 4 h, and 24 h). The analysis identified more than 4000 proteins; which were clustered using PatternLab for proteomics and then linked to Ras signaling, tissue homeostasis, induction of apoptosis, metallopeptidase activity, and ubiquitin-protein ligase activity. Our results make available one of the most complete protein repositories for the A172. Moreover, we detected the phosphorylation of GSK3β (Glycogen synthase kinase) and the inhibition of ERK's (extracellular signal regulated kinase) phosphorylation after 10′, which suggests a new mechanism of POH's activation for apoptosis. © 2010 Elsevier B.V. All rights reserved.
da Cunha M.E.,Federal University of Rio Grande do Sul |
Schneider J.K.,Federal University of Rio Grande do Sul |
Brasil M.C.,Federal University of Rio Grande do Sul |
Cardoso C.A.,Chemistry Institute |
And 7 more authors.
Microchemical Journal | Year: 2013
This paper describes the use of GC. ×. GC/qMS for the characterization of bio-oil from the pyrolysis of sugar cane straw and its fractions (from pressurized liquid fractionation by solvent elution). This is the first use of this technique for a bio-oil characterization. The GC. ×. GC/qMS allied to some computational tools, allowed the identification and classification of the compounds according to many factors such as chemical class, number of carbons, number of substituents in the carbonic chain, molecular weight and main peaks in fragmentation spectra. It used also the LTPRI (linear-temperature-programmed retention index) system for the confirmation of the identification of some of the compounds in the bio-oil and fractions. It found a total number of 331 compounds tentatively identified in the crude bio-oil and 166 were confirmed by LTPRI identification. The fractionation step promoted a better selectivity of the compounds in the fractions, allowing the identification of a greater number of compounds. © 2013 Elsevier B.V.
De Freitas Araujo M.G.,São Paulo State University |
Pacifico M.,Chemistry Institute |
Vilegas W.,Chemistry Institute |
Dos Santos L.C.,Chemistry Institute |
And 5 more authors.
Medical Mycology | Year: 2013
The purpose of this study was to evaluate the in vitro anticandidal activity of a methanolic extract of Syngonanthus nitens scapes against different Candida species and clinical isolates from patients with vulvovaginal candidiasis (VVC), and its effect in vivo in the treatment of vaginal infection. Chemical characterization of the extract was performed by HPLC-UV analyses and showed the presence of flavones derivatives. The extract was effective against several Candida strains from our collection and species recovered from VVC patients, and was able to inhibit the yeast-hyphal transition. No cytotoxic activity against human female reproductive tract epithelial cells and no hemolytic activity against human red blood cells were observed. In the in vivo model of VVC, we evaluated the efficacy of the intravaginal treatment with a cream containing the extract at doses of 0.5, 1.0 and 2.0%. The treatment eradicated the vaginal fungal burden in infected rats after 8 days of treatment. S. nitens extract could be considered as an effective and non-toxic natural antifungal agent in the treatment of vulvovaginal candidiasis. © 2013 ISHAM.
Sordi M.L.T.,Chemistry Institute |
Riegel I.C.,Centro Universitario Feevale |
Ceschi M.A.,Chemistry Institute |
Muller A.H.E.,University of Bayreuth |
Petzhold C.L.,Chemistry Institute
European Polymer Journal | Year: 2010
New block copolymers with narrow molecular weight distribution fenced(frac(over(M, -)w, over(M, -)n) = 1.04 s(-) 1.14) based on (2,3-epithiopropylmethacrylate) (ETMA), methylmethacrylate (MMA) and n-butylmethacrylate (nBMA) have been successfully synthesized via reversible addition-fragmentation transfer (RAFT) polymerization. First, RAFT homopolymerization of ETMA and MMA was carried out using 2-(2-cyanopropyl) dithiobenzoate (CPDB) as the chain transfer agent (CTA) and 2,2-azobisisobutyronitrile (AIBN) as the initiator. PETMA-b-P(nBMA) copolymers were synthesized using PETMA homopolymers as the macro-chain transfer agent (MCTA), while PMMA-b-PETMA diblock copolymers were synthesized using PMMA as the MCTA. The evolution of the molecular weight and molecular weight distribution of the homo- and co-polymers were compatible with the RAFT polymerization features. Thin films from the block copolymers were prepared by spin coating a 1 wt% polymer solution from toluene, chloroform or THF. After the preparation, the films were annealed under 80% vapor pressure of chloroform for 1, 2 and 4 h and investigated with scanning electron microscopy (SEM). The most interesting results were found in the films prepared using PETMA-b-P(nBMA) copolymers (over(M, -)n = 54, 000 g mol- 1). The observed images suggested the formation of hybrid lamellar structures, ascribed to the combination of its higher molecular weight and solvents viscosity. © 2009 Elsevier Ltd. All rights reserved.
Turhan H.,Chemistry Institute |
Atalar T.,Chemistry Institute |
Erdem N.,Chemistry Institute |
Ozden C.,Chemistry Institute |
And 4 more authors.
Propellants, Explosives, Pyrotechnics | Year: 2013
Hexamethylenetetramine dinitrate (HDN) is a rather weak explosive but is used as a precursor for the synthesis of RDX, one of the most important secondary nitramine explosives. HDN has limited application because of its hygroscopic character. This paper reports on the synthesis and characterization of HDN in high yield and purity by the reaction of hexamine with nitric acid at temperatures below 15 °C. It was characterized by FTIR and 1H NMR spectroscopy, Scanning Electron Microscopy (SEM) and Liquid Chromatography/Mass Spectrometry (LC/MS) measurements. The thermal characteristics of HDN were determined by DSC and TG/DTA. The DSC curve of HDN shows an endothermic peak at 170.5 °C corresponding to the melting point of HDN, followed by two exothermic peaks at 174.0 °C and 200.5 °C due to the decomposition. The differences in the thermal behavior of HDN samples, which were thermally aged at 50 °C, 100 °C, and 150 °C in a nitrogen atmosphere were examined. Additionally, some quantum chemical properties of the nitration of hexamethylenetetramine were calculated. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ates M.,Chemistry Institute |
Temel S.,Chemistry Institute |
Oz P.H.,Chemistry Institute |
Koroglu H.J.,Chemistry Institute
Bituminous Mixtures and Pavements VI - Proceedings of the 6th International Conference on Bituminous Mixtures and Pavements, ICONFBMP 2015 | Year: 2015
The objective of this study is to analyze the effects of organic and inorganic warm mix asphalt additives on bitumen viscosity by ring and ball softening point device, rotational viscometer and workability device. Sasobit and Aspha-min are used as commercial organic and inorganic additives, respectively. Viscosity experiments are the first step of the laboratory stage, to determine the changes in bitumen characteristics caused by adding warmmix asphalt additives. Viscosity measurement is an appropriate method for organic and chemical additives as they can finely disperse and show their effect directly in bitumen. However, effects of inorganic additives on bitumen cannot be monitored by means of a viscometer. Due to this reason, a workability device was designed to measure the contribution of the additive to bitumen by measuring torque changes with adjustable temperature, time and mixing speed. © 2015 Taylor & Francis Group, London.
Turan A.Z.,Chemistry Institute |
Elbeyli Y.,Chemistry Institute |
Kalafatoglu I.E.,Marmara University
Journal of the Electrochemical Society | Year: 2012
In the present work, membrane electrolysis of nearly saturated borax solution prepared from borax pentahydrate (Na2B4O 7.5H2O) was studied. Mono layer cation-exchange membrane (Nafion 551) was used as a separator in a two-compartment electrolysis cell for the production of sodium hydroxide and boric acid. The anolyte concentration was adjusted in order to obtain a Na2O/B2O3 mol ratio of 0.1 by dissolving boric acid and borax pentahydrate together. Experiments were performed in continuous operation mode by feeding nearly saturated borax solution. The effects of different catholyte concentrations (10, 20, and 30% NaOH) on the current efficiency and the specific energy consumption were calculated and the quality of boric acid products was determined. © 2012 The Electrochemical Society. All right reserved.