66 research outputs found
Possible in vivo mechanisms involved in photodynamic therapy using tetrapyrrolic macrocycles
Role of the JNK/c-Jun/AP-1 signaling pathway in galectin-1-induced T-cell death
Galectin-1 (gal-1), an endogenous β-galactoside-binding protein, triggers T-cell death through several mechanisms including the death receptor and the mitochondrial apoptotic pathway. In this study we first show that gal-1 initiates the activation of c-Jun N-terminal kinase (JNK), mitogen-activated protein kinase kinase 4 (MKK4), and MKK7 as upstream JNK activators in Jurkat T cells. Inhibition of JNK activation with sphingomyelinase inhibitors (20 μM desipramine, 20 μM imipramine), with the protein kinase C-δ (PKCδ) inhibitor rottlerin (10 μM), and with the specific PKCθ pseudosubstrate inhibitor (30 μM) indicates that ceramide and phosphorylation by PKCδ and PKCθ mediate gal-1-induced JNK activation. Downstream of JNK, we observed increased phosphorylation of c-Jun, enhanced activating protein-1 (AP-1) luciferase reporter, and AP-1/DNA-binding in response to gal-1. The pivotal role of the JNK/c-Jun/AP-1 pathway for gal-1-induced apoptosis was documented by reduction of DNA fragmentation after inhibition JNK by SP600125 (20 μM) or inhibition of AP-1 activation by curcumin (2 μM). Gal-1 failed to induce AP-1 activation and DNA fragmentation in CD3-deficient Jurkat 31-13 cells. In Jurkat E6.1 cells gal-1 induced a proapoptotic signal pattern as indicated by decreased antiapoptotic Bcl-2 expression, induction of proapoptotic Bad, and increased Bcl-2 phosphorylation. The results provide evidence that the JNK/c-Jun/AP-1 pathway plays a key role for T-cell death regulation in response to gal-1 stimulation
Alpha thalassaemia-mental retardation, X linked
X-linked alpha thalassaemia mental retardation (ATR-X) syndrome in males is associated with profound developmental delay, facial dysmorphism, genital abnormalities and alpha thalassaemia. Female carriers are usually physically and intellectually normal. So far, 168 patients have been reported. Language is usually very limited. Seizures occur in about one third of the cases. While many patients are affectionate with their caregivers, some exhibit autistic-like behaviour. Patients present with facial hypotonia and a characteristic mouth. Genital abnormalities are observed in 80% of children and range from undescended testes to ambiguous genitalia. Alpha-thalassaemia is not always present. This syndrome is X-linked recessive and results from mutations in the ATRX gene. This gene encodes the widely expressed ATRX protein. ATRX mutations cause diverse changes in the pattern of DNA methylation at heterochromatic loci but it is not yet known whether this is responsible for the clinical phenotype. The diagnosis can be established by detection of alpha thalassaemia, identification of ATRX gene mutations, ATRX protein studies and X-inactivation studies. Genetic counselling can be offered to families. Management is multidisciplinary: young children must be carefully monitored for gastro-oesophageal reflux as it may cause death. A number of individuals with ATR-X are fit and well in their 30s and 40s
Mineralogical evolution of cement pastes at early ages based on thermogravimetric analysis (TGA)
[EN] Ordinary thermogravimetric analysis (TG) and high-resolution TG tests were carried out on three different Portland cement pastes to study the phases present during the first day of hydration. Tests were run at 1, 6, 12 and 24 h of hydration, in order
to determine the phases at these ages. High-resolution TG tests were used to separate decompositions presented in the 100Âż200 C interval. The non-evaporable water determined by TG was used to determine hydration degree for the different ages. The effect of particle size distribution (PSD) on mineralogical evolution was established, as well as the addition of calcite as mineralogical filler. Finer PSD and calcite addition accelerate the hydration process, increasing the hydration degree on the first day of eaction between water and cement. According to high-resolution TG results, it was demonstrated that ettringite was the only decomposed phase in the 100Âż200 C interval during the first 6 h of hydration for all studied cements. C-S-H phase starts to appear in all cements after 12 h of hydration.Funding was provided by Colciencias (Grant No. Convocatoria 567-2012).Gaviria, X.; Borrachero Rosado, MV.; Paya Bernabeu, JJ.; MonzĂł Balbuena, JM.; TobĂłn, J. (2018). Mineralogical evolution of cement pastes at early ages based on thermogravimetric analysis (TGA). Journal of Thermal Analysis and Calorimetry. 132(1):39-46. https://doi.org/10.1007/s10973-017-6905-0S39461321Benboudjema F, Meftah JM, Torernti F. Interaction between drying, shrinkage, creep and cracking phenomena in concrete. Eng Struct. 2005;27:239–50.Holt E. Contribution of mixture design to chemical and autogenous shrinkage of concrete at early ages. Cem Concr Res. 2005;35:464–72.Darquennes A, Staquet S, Delplancke-Ogletree MP, Espion B. Effect of autogenous deformation on the cracking risk of slag cement concretes. Cem Concr Compos. 2011;33:368–79.Slowik V, Schmidt M, Fritzsch R. Capillary pressure in fresh cement-based materials and identification of the air entry value. Cem Concr Compos. 2008;30(7):557–65.Evju C, Hansen S. Expansive properties of ettringite in a mixture of calcium aluminate cement, Portland cement and Ăź-calcium sulfate hemihydrates. Cem Concr Res. 2001;31:257–61.Bentz DP, Jensen OM, Hansen KK. Olesen, Stang, H. Haecker, C.J. Influence of cement particle-size distribution on early age autogenous strain and stresses in cement-based materials. J Am Ceram Soc. 2001;84(1):129–35.Barcelo L, Moranville M, Clavaud B. Autogenous shrinkage of concrete: a balance between autogenous swelling and self-desiccation. Cem Concr Res. 2005;35(1):177–83.Bouasker M, Mounanga P, Turcry P, Loukili A, Khelidj A. Chemical shrinkage of cement pastes and mortars at very early age: effect of limestone filler and granular inclusions. Cem Concr Compos. 2008;30(1):13–22.Bentz DP. A review of early-age properties of cement-based materials. Cem Concr Res. 2008;38(2):196–204.Ozawa T. Controlled rate thermogravimetry. New usefulness of controlled rate thermogravimetry revealed by decomposition of polyimide. J Therm Anal Calorim. 2000;59:375–84.Ramachandran VS, Paroli RM, Beaudoin JJ, Delgado AH. Thermal analysis of construction materials. Building materials series. New York: Noyes Publications; 2003.Zanier A. High-resolution TG for the characterization of diesel fuel additives. J Therm Anal Calorim. 2001;64:377–84.TobĂłn JI, Payá J, Borrachero MV, Restrepo OJ. Mineralogical evolution of Portland cement blended with silica nanoparticles and its effect on mechanical strength. Constr Build Mater. 2012;36:736–42.Singh M, Waghmare S, Kumar V. Characterization of lime plasters used in 16th century Mughal Monument. J Archeol Sci. 2014;42:430–4.Majchrzak-Kuçeba I. Thermogravimetry applied to characterization of fly ash-based MCM-41 mesoporous materials. J Therm Anal Calorim. 2012;107:911–21.Silva ACM, Gálico DA, Guerra RB, Legendre AO, Rinaldo D, Galhiane MS, Bannach G. Study of some volatile compounds evolved from the thermal decomposition of atenolol. J Therm Anal Calorim. 2014;115:2517–20.Rios-Fachal M, Gracia-Fernández C, LĂłpez-Beceiro J, GĂłmez-Barreiro S, TarrĂo-Saavedra J, Ponton A, Artiaga R. Effect of nanotubes on the thermal stability of polystyrene. J Therm Anal Calorim. 2013;113:481–7.Yamarte L, Paxman D, Begum S, Sarkar P, Chambers A. TG measurement of reactivity of candidate oxygen carrier materials. J Therm Anal Calorim. 2014;116:1301–7.Borrachero MV, Payá J, Bonilla M, MonzĂł J. The use of thermogravimetric analysis technique for the characterization of construction materials. The gypsum case. J Therm Anal Calorim. 2008;91(2):503–9.TobĂłn JI, Payá J, Borrachero MV, Soriano L, Restrepo OJ. Determination of the optimum parameters in the high resolution thermogravimetric analysis (HRTG) for cementitious materials. J Therm Anal Calorim. 2012;107:233–9.Kuzielova E, Ĺ˝emliÄŤka M, Másilko, J, Palou, M.T. Effect of additives on the performance of Dyckerhoff cement, Class G, submitted to simulated hydrothermal curing. J Therm Anal Calorim. Accepted 29 Oct 2017Genc M, Genc ZK. Microencapsulated myristic acid–fly ash with TiO2 shell as a novel phase change material for building application. J Therm Anal Calorim. Accepted 24 Oct 2017.Singh M, Kumar SV, Waghmare SA. The composition and technology of the 3–4th century CE decorative earthen plaster of Pithalkhora caves, India. J Archeol Sci. 2016;7:224–37.Liu L, Liu Q, Cao Y, Pan WP. The isothermal studies of char-CO2 gasification using the high-pressure thermo-gravimetric method. J Therm Anal Calorim. 2015;120:1877–82.Majchrzak-Kuce I, Bukalak-Gaik D. Regeneration performance of metal–organic frameworks TG-vacuum tests. J Therm Anal Calorim. 2016;125:1461–6.Ion RM, Radovici C, Fierascu RC, Fierascu I. Thermal and mineralogical investigations of iron archaeological Materials. J Therm Anal Calorim. 2015;121:1247–53.Rupasinghe M, San Nicolas R, Mendis P, Sofi M, Ngo T. Investigation of strength and hydration characteristics in nano-silica incorporated cement paste. Cem Concr Compos. 2017;80:17–30.Esteves PL. On the hydration of water-entrained cement–silica systems: combined SEM, XRD and thermal analysis in cement pastes. Thermochim Acta. 2011;518:27–35.Riesen R. Adjustment of heating rate for maximum resolution in TG and TMA (MaxRes). J Therm Anal. 1998;53:365–74.Lim S, Mondal P. Micro- and nano-scale characterization to study the thermal degradation of cement-based materials. Mater Charact. 2014;92:15–25.Gill PS, Sauerbrunn SR, Crowe BS. High resolution thermogravimetry. J Therm Anal. 1992;38:255–66.Mounanga P, Khelidj A, Loukili A, Baroghel-Bouny V. Predicting Ca(OH)2 content and chemical shrinkage of hydrating cement pastes using analytical approach. Cem Concr Res. 2004;34:255–65.Zeng Q, Li K, Fen-chong T, Dangla P. Determination of cement hydration and pozzolanic reaction extents for fly-ash cement pastes. Constr Build Mater. 2012;27:560–9.Parrott LP, Geiker M, Gutteridge WA, Killoh D. Monitoring Portland cement hydration: Comparison of methods. Cem Concr Res. 1990;20:919–26.Hewlett PC. Lea’s chemistry of cement and concrete. 4th ed. Oxford: Elsevier Science & Technology Books; 2004.ASTM C305 Standard practice for mechanical mixing of hydraulic cement pastes and mortars of plastic consistency. ASTM International, West Conshohocken, PA; 2012.Taylor HF. Cement chemistry. 2nd ed. Westminster: Thomas Telford; 1997.Nadelman EI, Freas DJ, Kurtis KE. Nano- and microstructural characterization of Portland limestone cement paste. In: Nanotechnology in construction. Proceedings of NICOM 5. 2015. p. 87–92
Comparison of mouse mammary gland imaging techniques and applications: Reflectance confocal microscopy, GFP Imaging, and ultrasound
<p>Abstract</p> <p>Background</p> <p>Genetically engineered mouse models of mammary gland cancer enable the <it>in vivo </it>study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue.</p> <p>Methods</p> <p>We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging.</p> <p>Results</p> <p>In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice.</p> <p>Conclusion</p> <p>In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary.</p
Hybrid nanostructured coating for increased resistance of prosthetic devices to staphylococcal colonization
1,5-dihydroxyanthraquinones and an anthrone from roots of Rumex crispus
From the roots of Ruinex crispus, two known anthraquinones and a new one together with a new anthrone were isolated and the structures of compounds 1-4 were elucidated by spectroscopic means. The singlet oxygen generation capacity was tested with 1,3-diphenylisobenzofuran (DPBF) for compounds 1-4
Study of the fluorescence-quenching of Mg-TNP by anionic anthraquinones
The fluorescence quenching of magnesium 5,10,15,20-tetra-p-naphtyl-porphyrin (Mg-TNP) has been studied in benzene using 9,10-anthraquinone-2-sulfonic acid sodium salt (An 1), 9,10 -anthraquinone-2,6-disulfonic acid sodium salt monohydrate (An 2), 9,10-anthraquinone-1,5-disulfonic disodium salt monohydrate (An 3) as quenchers. The fluorescence quenching rate constants are deduced from the Stern-Volmer curves and it is postulated that the quenching occurs via the formation of a charge transfer complex formation. For all these cases, R(o)values are in the 1-10 Angstrom range, which correspond to one singlet quenching processes by diffusion controlled energy transfer. Electron-exchange and/or electron transfer processes are expected to proceed also at these distances. The quenching mechanism is concerted one between static quenching with energy transfer (due to long-range dipole-dipole interaction between excited anthraquinone molecules (donor) and the ground state acceptor molecule Mg-TNP) and electron transfer which should occur from singlet excited state of Mg-TNP to donor anthraquinone molecule, leading to formation of stable radical anion and cations
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