69 research outputs found
Asymmetry of 13C labeled 3-pyruvate affords improved site specific labeling of RNA for NMR spectroscopy
Selective isotopic labeling provides an unparalleled window within which to study the structure and dynamics of RNAs by high resolution NMR spectroscopy. Unlike commonly used carbon sources, the asymmetry of 13C-labeled pyruvate provides selective labeling in both the ribose and base moieties of nucleotides using E. coli variants, that until now were not feasible. Here we show that an E. coli mutant strain that lacks succinate and malate dehydrogenases (DL323) and grown on [3-13C]-pyruvate affords ribonucleotides with site specific labeling at C5′ (~95%) and C1′ (~42%) and minimal enrichment elsewhere in the ribose ring. Enrichment is also achieved at purine C2 and C8 (~95%) and pyrimidine C5 (~100%) positions with minimal labeling at pyrimidine C6 and purine C5 positions. These labeling patterns contrast with those obtained with DL323 E. coli grown on [1, 3-13C]-glycerol for which the ribose ring is labeled in all but the C4′ carbon position, leading to multiplet splitting of the C1′, C2′ and C3′ carbon atoms. The usefulness of these labeling patterns is demonstrated with a 27-nt RNA fragment derived from the 30S ribosomal subunit. Removal of the strong magnetic coupling within the ribose and base leads to increased sensitivity, substantial simplification of NMR spectra, and more precise and accurate dynamic parameters derived from NMR relaxation measurements. Thus these new labels offer valuable probes for characterizing the structure and dynamics of RNA that were previously limited by the constraint of uniformly labeled nucleotides
A review of elliptical and disc galaxy structure, and modern scaling laws
A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their
models to describe the radial distribution of stars in `nebulae'. This article
reviews the progress since then, providing both an historical perspective and a
contemporary review of the stellar structure of bulges, discs and elliptical
galaxies. The quantification of galaxy nuclei, such as central mass deficits
and excess nuclear light, plus the structure of dark matter halos and cD galaxy
envelopes, are discussed. Issues pertaining to spiral galaxies including dust,
bulge-to-disc ratios, bulgeless galaxies, bars and the identification of
pseudobulges are also reviewed. An array of modern scaling relations involving
sizes, luminosities, surface brightnesses and stellar concentrations are
presented, many of which are shown to be curved. These 'redshift zero'
relations not only quantify the behavior and nature of galaxies in the Universe
today, but are the modern benchmark for evolutionary studies of galaxies,
whether based on observations, N-body-simulations or semi-analytical modelling.
For example, it is shown that some of the recently discovered compact
elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to
appear in "Planets, Stars and Stellar
Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references
incl. many somewhat forgotten, pioneer papers. Original submission to
Springer: 07-June-201
Inhibition of invasion and metastasis of human liver cancer HCCLM3 cells by portulacerebroside A
CONTEXT:
Portulacerebroside A (PCA) is a novel cerebroside compound isolated from Portulaca oleracea L. (Portulacaceae), an edible and medicinal plant distributed in the temperate and tropical zones worldwide.
OBJECTIVE:
This study investigates the effects of PCA in human liver cancer HCCLM3 cells on metastasis and invasion.
MATERIALS AND METHODS:
After the cells were treated with PCA (2.5, 5, and 10 μg/ml) for 6, 12, 24, or 48 h, adhesion, transwell invasion, and scratch tests were conducted and cell functions were evaluated. Western blot and FQ-RT-PCR assays explored the mechanism of PCA-inhibited invasion and metastasis in the cells.
RESULTS:
The adhesion rate of the cells was suppressed at 0.5 h (79.4 ± 1.0, 68.7 ± 1.3, and 58.1 ± 1.3%, versus 100 ± 1.5% in the control), 1 h (78.2 ± 1.2, 70.9 ± 1.6, and 55.4 ± 1.9%, versus 100 ± 1.2% in the control), and 1.5 h (71.6 ± 1.1, 62.3 ± 0.9, and 50.4 ± 0.9%, versus 100 ± 1.1% in the control). The 24 h invasion ability was decreased (356.6 ± 11.2, 204.0 ± 17.6, and 113.0 ± 9.5%, versus 443.6 ± 15.4% in the control). The migration capability was also restrained by PCA for 24 h (324.8 ± 25.4, 250.4 ± 21.0, and 126.3 ± 10.1, versus 381.6 ± 30.6 in the control) and 48 h (470.3 ± 34.3, 404.0 ± 19.7, and 201.0 ± 15.4, versus 752.0 ± 63.6 in the control). There was an increase in the mRNA and protein expression levels of TIMP-2 and nm23-H1, inhibition in the mRNA expression of MTA1, MMP-2, and MMP-9, and suppression in the protein expression of MTA1, RhoA, Rac1/Cdc42, MMP-2, but not RhoC and MMP-9.
CONCLUSION:
PCA suppresses the invasion and metastasis of HCCLM3 cells possibly by modulation of the mRNA and protein expression of related parameters. This is the first study to reveal a new potential therapeutic application of PCA in antimetastatic therapy for liver cancer
Neurodegenerative processes in Huntington's disease
Huntington's disease (HD) is a complex and severe disorder characterized by the gradual and the progressive loss of neurons, predominantly in the striatum, which leads to the typical motor and cognitive impairments associated with this pathology. HD is caused by a highly polymorphic CAG trinucleotide repeat expansion in the exon-1 of the gene encoding for huntingtin protein. Since the first discovery of the huntingtin gene, investigations with a consistent number of in-vitro and in-vivo models have provided insights into the toxic events related to the expression of the mutant protein. In this review, we will summarize the progress made in characterizing the signaling pathways that contribute to neuronal degeneration in HD. We will highlight the age-dependent loss of proteostasis that is primarily responsible for the formation of aggregates observed in HD patients. The most promising molecular targets for the development of pharmacological interventions will also be discussed
Candidate Gene Polymorphism for IL-Rγ and ChB6 Genes in the Indigenous Chicken of North Western Himalayan State of Himachal Pradesh, India
Present investigation was carried out to identify DNA polymorphism of IL-2Rγ and ChB6 genes. Sixty five birds belonging to the indigenous chicken of Himachal Pradesh were utilized. Good quality DNA samples were subjected to PCR-RFLP analysis using chicken specific primers. Overnight restriction enzyme digestion was carried out at 37°C with IU Hph I and Pvu II for IL-2Rγ and ChB6 genes, respectively. Amplification of IL-2Rγ gene resolved a 600 bp amplicon in all samples, which upon digestion with Hph I RE yielded three patterns i.e. Hph I aa , Hph I a/b and Hph I bb. Hph I aa genotype revealed 465 and 42 bp fragments while Hph I bb genotypes revealed 454, 134, 104 and 42 bp fragments. Hph I a/b genotype resolved 465, 454, 134, 104 and 42 bp fragments. The frequencies of these patterns were 0.47, 0.23 and 0.30 for Hph I aa, Hph I a/b and Hph I bb, respectively. The amplification of Chicken B cell marker (ChB6) generated 215 bp amplicon in all the samples, which upon digestion with Pvu II generated two pattern i.e. Pvu II aa and Pvu II bb respectively. Pvu II aa generated 215 bp fragments while Pvu II bb generated 215, 147 and 68 bp, respectively. The frequencies of the PCR-RFLP pattern of ChB6 gene were 0.57 and 0.43, respectively
Socio-economic status of Spiti horse owners vis-a-vis horse management in native tract
Not AvailableSpiti horses are widely used for carrying men and material in the hilly terrains of Lahoul and Spiti in Himalayan region. People living in Pin Valley rear these horses mainly for breeding purpose. The study was planned to know socio-economic status of Spiti horse owners and managemental practices followed by them. The primary data was collected from 50 horse owners belonging to Pin Valley of Spiti Sub-Division of Lahoul and Spiti District. The people engaged in horse rearing belong to mainly Buddhist community. Majority of them were poor and illiterate. Women and children contribute significantly in equine husbandry. Selection of breeding stallion, sharing of upkeep of stallion, castration of surplus males etc are the important practices which are performed under the supervision of elderly and experienced horse breeders more or less on scientific lines. The mares freely roam with the stallion from April onwards and get covered through natural mating. Foaling generally occurs in the month of April and May and most of the mares conceive during the foal heat. They sell their equines in International Lavi Fair at Rampur in Shimla District and Ladarcha Fair Kaza in Lahoul and Spiti District. Selling price varies from 10,000 to 30,000 depending upon age, sex and physical condition of the horse. It was concluded that horses were an important component in the life of people of Pin Valley. Potential areas for intervention were identified as training of veterinarian for AI, treatment, husbandry practices of equines and disease investigation as well as including of height as a criterion in stallion selection.Not Availabl
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