Regulación de genes que afectan la biosíntesis de compuestos de azufre en cerveza

RESUMEN Durante la fermentación alcohólica, la levadura producirá submetabolitos que alteran las características de la cerveza. Los compuestos volátiles de azufre (CVA) son generados por la activación de genes involucrados en el metabolismo de asimilación de sulfatos, sulfitos y síntesis de aminoácidos. Identificamos los genes que participan en la producción de CVA y su respuesta bajo distintas condiciones de proceso. Utilizamos dos cepas de levadura sometidas a diferentes tipos de mosto y evaluamos su respuesta genética. Los resultados mostraron que la producción de CVA depende de la constitución genética de la cepa y su interacción con el mosto. ABSTRACT During brewing process, the yeast will produce secondary metabolites altering the characteristics of the beer. Volatile sulfur compounds (CVA) are generated by activation of genes involved in the metabolism of assimilation of sulfates, sulfites, and amino acid synthesis. We identified genes involved in the production of VCA and its response under different process conditions. We used two yeast strains fermenting different types of worts, and we evaluated their genetic response. The results showed that the production of CVA depends on the genetic constitution of the strain and its interaction with the wor

Effects of the Spin-Orbit and Tensor Interactions on the M1M1 and E2E2 Excitations in Light Nuclei

The effects of varying the spin-orbit and tensor components of a realistic interaction on $M1$ excitation rates and $B(E2)'s$ are studied on nuclei in the $0p$ and $1s-0d$ shells. Not only the total $M1$ but also the spin and orbital parts separately are studied. The single-particle energies are first calculated with the same interaction that is used between the valence nucleons. Later this stringent condition is relaxed somewhat and the $1s$ level is raised relative to $0d$. For nuclei up to $^{28}Si$, much better results i.e stronger $B(M1)$ rates are obtained by increasing the strength of the spin-orbit interaction relative to the free value. This is probably also true for $^{32}S$, but $^{36}Ar$ presents some difficulties. The effects of weakening the tensor interaction are also studied. On a more subtle level, the optimum spin-orbit interaction in the lower half of the $s-d$ shell, as far as $M1$ excitations are concerned, is substantially larger than the difference $E(J=3/2^+)_1-E(J=5/2^+)_1=5.2~MeV$ in $^{17}O$. A larger spin-orbit splitting is also needed to destroy the triaxiality in $^{22}Ne$. Also studied are how much $M1$ orbital and spin strength lies in an observable region and how much is buried in the grass at higher energies. It is noted that for many nuclei the sum $B(M1)_{orbital}+B(M1)_{spin}$ is very close to $B(M1)_{total}$, indicating that the summed cross terms are very small.Comment: 39 pages, revtex 3.

Caracterización de cepas mexicanas de bacillus thuringiensis tóxicas para larva de lepidópteros y coleópteros

Se caracterizaron las cepas de Bacillus thuringiensis C-4, C-9, GM-7, y GM-10, que fueron asiladas del noreste de México, y seleccionadas por su alta toxicidad contra lepidópteros y coleópteros de importancia agrícola, siguiendo las guías de la Agencia de Protección del Medio Ambiente (EPA) de los Estados Unidos de Norte América. La serotipificación reveló que ninguna de las cepas estudiadas produjo β-exotoxina o fue activa contra mosquitos. Se encontró que GM-7 y GM-10 fueron sensibles a los fagos R-41 y CP-51. Todas las cepas sintetizaron proteínas del cristal de 130–140 kDa. Las cepas C-4, GM-7, y GM-16 10 expresaron genes cry1, y la C-9 expresó los genes cry3 y cry7/8. Además, se observó que sólo la δ-endotoxina (cristal) de C4 y C9, solas o en combinación con esporas, causaron necrosis tisular cuando se inyectaron subcutáneamente, y ésta fue similar a la causada por la cepa productora de β-exotoxina HD-41. Esta necrosis se suprimió significativamente con el uso de pentoxifilina, que es un inhibidor de la producción de factor de necrosis tumoral-α, lo cual sugirió que esta citosina estuvo involucrada en el efecto observado. Los resultados demuestran que las cepas GM-7 y GM-10 son seguras para mamíferos de acuerdo a los lineamientos de la EPA. Además, se discute el potencial de la cepa C-9 para el control de varios coleópteros de importancia agrícola, y la inducción de necrosis tisular en ratones por C-4 y C-9

Enhancing chemosensitivity to gemcitabine via RNA interference targeting the catalytic subunits of protein kinase CK2 in human pancreatic cancer cells

<p>Abstract</p> <p>Background</p> <p>Pancreatic cancer is a complex genetic disorder that is characterized by rapid progression, invasiveness, resistance to treatment and high molecular heterogeneity. Various agents have been used in clinical trials showing only modest improvements with respect to gemcitabine-based chemotherapy, which continues to be the standard first-line treatment for this disease. However, owing to the overwhelming molecular alterations that have been reported in pancreatic cancer, there is increasing focus on targeting molecular pathways and networks, rather than individual genes or gene-products with a combination of novel chemotherapeutic agents.</p> <p>Methods</p> <p>Cells were transfected with small interfering RNAs (siRNAs) targeting the individual CK2 subunits. The CK2 protein expression levels were determined and the effect of its down-regulation on chemosensitization of pancreatic cancer cells was investigated.</p> <p>Results</p> <p>The present study examined the impact on cell death following depletion of the individual protein kinase CK2 catalytic subunits alone or in combination with gemcitabine and the molecular mechanisms by which this effect is achieved. Depletion of the CK2α or -α' subunits in combination with gemcitabine resulted in marked apoptotic and necrotic cell death in PANC-1 cells. We show that the mechanism of cell death is associated with deregulation of distinct survival signaling pathways. Cellular depletion of CK2α leads to phosphorylation and activation of MKK4/JNK while down-regulation of CK2α' exerts major effects on the PI3K/AKT pathway.</p> <p>Conclusions</p> <p>Results reported here show that the two catalytic subunits of CK2 contribute differently to enhance gemcitabine-induced cell death, the reduced level of CK2α' being the most effective and that simultaneous reduction in the expression of CK2 and other survival factors might be an effective therapeutic strategy for enhancing the sensitivity of human pancreatic cancer towards chemotherapeutic agents.</p

Using Argo data to investigate the Meridional Overturning Circulation in the North Atlantic

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 57 (2010): 29-36, doi:10.1016/j.dsr.2009.10.003.Using a variety of oceanographic data, including direct volume transports in the Florida 19 Strait, and Argo float profiles and drift velocities at 24 and 36N in the North Atlantic, inverse calculations are presented in which the net meridional transport, 20 down to a depth of approximately 1600 m, is estimated at both latitudes for a five year period 2003-2007. The upper ocean is divided into 7 layers using neutral density, and mass conservation constraints have been applied to a closed box bounded by these latitudes, including the Florida Strait. Ekman layer transports have been included in the top-most layer, and the inverse calculation has solved for changes from the initial reference velocities, Ekman and Florida Strait transports, given a priori estimates on the accuracy of each of these quantities. Solutions with and without transformations due to Mediterranean Water (MW) formation are made. Our results indicate that 1) time-averaged transport estimates derived from Argo have significant less eddy noise than individual hydrographic sections, 2) Argo drift velocities provide information to the inverse solution for the ocean interior, and 3) comparison of the total integrated interior mass transports in the thermocline waters for the period 2003-2007 with the previous estimates based on trans-ocean hydrographic sections shows that the Meridional Overturning Circulation has not significantly changed since 1957.TJ would like to acknowledge support from NSF Grant OCE-0241354 and NOAA/CICOR grant NA17RJ1223

High pressure studies of palladium and platinum thioether macrocyclic dihalide complexes

The mononuclear macrocyclic Pd(II) complex cis-[PdCl2([9 aneS3)] ([9]aneS3 = 1,4,7-trithiacyclononane) converts at 44 kbar into an intensely coloured chain polymer exhibiting distorted octahedral co-ordination at the metal centre and an unprecedented [1233] conformation for the thioether ligand. The evolution of an intramolecular axial sulphur metal interaction and an intermolecular equatorial sulfur-metal interaction is central to these changes. High pressure crystallographic experiments have also been undertaken on the related complexes [PtCl2([9]aneS3)], [PdBr2([9]aneS3)],[PtBr2([9]aneS3)], [PdI2([9]aneS3)] and [PtI2([9]aneS3)] in order to establish the effects of changing the halide ligands and the metal centre on the behaviour of these complexes under pressure. While all complexes undergo contraction of the various interaction distances with increasing pressure, only[PdCl2([9]aneS3)] undergoes a phase change. Pressure-induced I…I interactions were observed for [PdI2([9]aneS3)] and [PtI2([9]aneS3)] at 19 kbar but the corresponding Br…Br interactions in [PdBr2([9]aneS3)] and [PtBr2([9]aneS3)] only become significant at much higher pressure (58 kbar. Accompanying DFT calculations have yielded interaction energies and bond orders for the sulphur metal interactions

Functional ectodomain of the hemagglutinin-neuraminidase protein is expressed in transgenic tobacco cells as a candidate vaccine against Newcastle disease virus.

Recently, the use of plants for the production of recombinant proteins has been well demonstrated with promising outcomes. In this study, an efficient Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) cells system expressing the ectodomain of hemagglutinin-neuraminidase (eHN) protein from Newcastle disease virus (NDV) strain AF2240 was established. Transgenic tobacco BY-2 cell cultures expressing the immunogenic eHN protein were generated and the translation efficiency of eHN protein was enhanced using the 5′-untranslated region of Nicotiana tabacum alcohol dehydrogenase gene (NtADH 5′-UTR) under the control of strong cauliflower mosaic virus (CaMV 35S) promoter. Transgenic lines verified by real-time PCR showed high level of eHN mRNA transcripts and immunoblotting confirmed the presence of 66 kD eHN protein. The eHN protein was stably produced in an average of 0.2–0.4 % total soluble protein. Green fluorescent protein-tagged eHN protein was expressed and localized at the cytosol of BY-2 cell. All mice receiving purified eHN protein from transgenic tobacco BY-2 cells produced specific anti-NDV antibodies. We concluded that plant made eHN elicit immune response and can serve as candidate vaccine against NDV

Immune-based therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer-related death. The immune-rich contexture of the HCC microenvironment makes this tumour an appealing target for immune-based therapies. Here, we discuss how the functional characteristics of the liver microenvironment can potentially be harnessed for the treatment of HCC. We will review the evidence supporting a therapeutic role for vaccines, cell-based therapies and immune-checkpoint inhibitors and discuss the potential for patient stratification in an attempt to overcome the series of failures that has characterised drug development in this disease area

Severe forms of partial androgen insensitivity syndrome due to p.L830F novel mutation in androgen receptor gene in a Brazilian family

<p>Abstract</p> <p>Background</p> <p>The androgen insensitivity syndrome may cause developmental failure of normal male external genitalia in individuals with 46,XY karyotype. It results from the diminished or absent biological action of androgens, which is mediated by the androgen receptor in both embryo and secondary sex development. Mutations in the androgen receptor gene, located on the X chromosome, are responsible for the disease. Almost 70% of 46,XY affected individuals inherited mutations from their carrier mothers.</p> <p>Findings</p> <p>Molecular abnormalities in the androgen receptor gene in individuals of a Brazilian family with clinical features of severe forms of partial androgen insensitivity syndrome were evaluated. Seven members (five 46,XY females and two healthy mothers) of the family were included in the investigation. The coding exons and exon-intron junctions of androgen receptor gene were sequenced. Five 46,XY members of the family have been found to be hemizygous for the c.3015C>T nucleotide change in exon 7 of the androgen receptor gene, whereas the two 46,XX mothers were heterozygote carriers. This nucleotide substitution leads to the p.L830F mutation in the androgen receptor.</p> <p>Conclusions</p> <p>The novel p.L830F mutation is responsible for grades 5 and 6 of partial androgen insensitivity syndrome in two generations of a Brazilian family.</p