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71.
AbstractMelatonin (N-acetyl-5-methoxy tryptamine), following discovery from the extracts of bovine pineal gland, has been detected in the pineal as well as several extra-pineal tissues/organs of different vertebrates including fish. The unique feature of melatonin in the pineal gland is its rhythmic biosynthesis and release in blood in synchronization with the environmental light-–dark cycle. Accordingly, melatonin produced in the pineal of an animal living in a changing environment is implicated to the regulation of seasonal reproduction by acting as a hormone at one or more levels of hypothalamo-hypophyseal-gonadal axis. Additionally, melatonin is known to act as a potent free-radical scavenger or antioxidant to influence maturation of oocytes. However, possible relationship between extra-pineal melatonin and seasonality of reproduction in any animal remains enigmatic. Perhaps, carp is the only known animal in which temporal patterns of melatonin levels in the serum as well as in the extracts of pineal, retina, ovary, gut, and liver have been studied in relation to the reproductive events in an annual cycle. The purpose of current review is to bring those fascinating, and arguably most important data together to underline their significance in the control of seasonal reproduction in subtropical fish in general and in carp in particular. 相似文献
72.
Kristiansen TZ Harsha HC Grønborg M Maitra A Pandey A 《Journal of proteome research》2008,7(11):4670-4677
Quantitative proteomic methodologies allow profiling of hundreds to thousands of proteins in a high-throughput fashion. This approach is increasingly applied to cancer biomarker discovery to identify proteins that are differentially regulated in cancers. Fractionation of protein samples based on enrichment of cellular subproteomes prior to mass spectrometric analysis can provide increased coverage of certain classes of molecules. We used a membrane protein enrichment strategy coupled with 18O labeling based quantitative proteomics to identify proteins that are highly expressed in cholangiocarcinomas. In addition to identifying several proteins previously known to be overexpressed in cholangiocarcinoma, we discovered a number of molecules that were previously not associated with cholangiocarcinoma. Using immunoblotting and immunohistochemical labeling of tissue microarrays, we validated Golgi membrane protein 1, Annexin IV and Epidermal growth factor receptor pathway substrate 8 (EPS8) as candidate biomarkers for cholangiocarcinomas. Golgi membrane protein 1 was observed to be overexpressed in 89% of cholangiocarcinoma cases analyzed by staining tissue microarrays. In light of recent reports showing that Golgi membrane protein 1 is detectable in serum, further investigation into validation of this protein has the potential to provide a biomarker for early detection of cholangiocarcinomas. 相似文献
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74.
Yi Sun Douglas Zhou Aaditya V. Rangan David Cai 《Journal of computational neuroscience》2009,27(3):369-390
We present an efficient library-based numerical method for simulating the Hodgkin–Huxley (HH) neuronal networks. The key components
in our numerical method involve (i) a pre-computed high resolution data library which contains typical neuronal trajectories
(i.e., the time-courses of membrane potential and gating variables) during the interval of an action potential (spike), thus
allowing us to avoid resolving the spikes in detail and to use large numerical time steps for evolving the HH neuron equations;
(ii) an algorithm of spike-spike corrections within the groups of strongly coupled neurons to account for spike-spike interactions
in a single large time step. By using the library method, we can evolve the HH networks using time steps one order of magnitude
larger than the typical time steps used for resolving the trajectories without the library, while achieving comparable resolution
in statistical quantifications of the network activity, such as average firing rate, interspike interval distribution, power
spectra of voltage traces. Moreover, our large time steps using the library method can break the stability requirement of
standard methods (such as Runge–Kutta (RK) methods) for the original dynamics. We compare our library-based method with RK
methods, and find that our method can capture very well phase-locked, synchronous, and chaotic dynamics of HH neuronal networks.
It is important to point out that, in essence, our library-based HH neuron solver can be viewed as a numerical reduction of
the HH neuron to an integrate-and-fire (I&F) neuronal representation that does not sacrifice the gating dynamics (as normally
done in the analytical reduction to an I&F neuron). 相似文献
75.
Sohal JS Singh SV Subodh S Sheoran N Narayanasamy K Singh PK Singh AV Maitra A 《Microbiological research》2009,164(3):330-337
Effective control of paratuberculosis and investigations of potential link to Crohn's disease have been hampered by the lack of effective assays for easy and accurate diagnosis of Mycobacterium avium subspecies paratuberculosis (Map). Map is extremely fastidious and depends on iron chelator (Mycobactin). Map strains from humans and sheep are very difficult to isolate and may require years to emerge. Therefore, small numbers of Map isolates have been maintained in available collections. This situation has limited the study of biodiversity of Map. Though, much is known about environmental and host factors that contribute to paratuberculosis disease, but little is known about bacterial genetic mechanism of infection. Diagnostic and strain typing markers still demand improvements. Complete genome sequence of Map K10 strain is available in public domain for comparative genomics with other mycobacteria and clinical isolates of Map. It is anticipated that the genome sequence will help in carrying molecular diagnosis and strain typing with respect to Map forward at rapid pace. This paper reviews the current diagnostic and strain typing markers, which may be useful in typing of clinical isolates in near future. 相似文献
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78.
Gondi?Mahendranath Akshatha?Venugopalan Rangan?Parimalan Parvatam?GiridharEmail author G.?A.?Ravishankar 《Plant Cell, Tissue and Organ Culture》2011,106(3):517-522
Bixa orellana L. is a tree native to South America known for its reddish orange pigment ‘annatto’ produced only on the aril portion of
its seeds. It is the most preferred natural food colorant next to saffron, having wide applications in the dairy industry
and also as a cosmeceutical. Normal root cultures of B. orellana were established under in vitro conditions on Murashige and Skoog (MS) medium containing α-naphthaleneacetic acid (NAA),
indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) at 0.05–0.2 mg l−1. The annatto pigment from in vitro-raised normal roots was extracted with chloroform, and later the ethanol-dissolved extract
was analyzed both qualitatively by thin-layer chromatography (TLC) and spectrophotometrically quantified followed by High
Performance Liquid Chromatography (HPLC) confirmation. The maximum amount of annatto pigment (346 ± 3.8 mg/100 g dry wt.)
and maximum root biomass (152 ± 2.5 mg dry wt.) were recorded after 45 and 60 days of growth, respectively, on MS medium containing
0.1 mg l−1 indole-3-butyric acid (IBA). Producing annatto pigment from normal root cultures under in vitro conditions is a novel approach
when compared to the natural annatto pigment that is produced only on the aril portion of seeds. This allows the production
of fresh pigment throughout the year. 相似文献
79.
Subclinical levels of circulating endotoxin are associated with the pathogenesis of diverse human inflammatory diseases, by mildly inducing the expression of proinflammatory mediators. In this study, we examined the molecular mechanism responsible for the effect of low-dose LPS in macrophages. In contrast to high-dose LPS, which activates NF-κB and induces the robust expression of proinflammatory mediators, we observed that low-dose LPS failed to activate NF-κB. Instead, it selectively activated C/EBPδ and removed nuclear repressors, including peroxisome proliferator-activated receptor α and retinoic acid receptor α, enabling a mild and leaky expression of proinflammatory mediators. The effect of low-dose LPS required IRAK-1, which interacts with and acts upstream of IκB kinase ε to contribute to LPS-mediated induction of C/EBPδ and proinflammatory mediators. Additionally, mice fed a high-fat diet acquired elevated levels of endotoxin and proinflammatory mediators in an IRAK-1-dependent fashion. Taken together, these data reveal a distinct pathway preferentially used by low-dose endotoxin in initiating low-grade inflammation. 相似文献
80.
A proteomic analysis of human bile 总被引:16,自引:0,他引:16
Kristiansen TZ Bunkenborg J Gronborg M Molina H Thuluvath PJ Argani P Goggins MG Maitra A Pandey A 《Molecular & cellular proteomics : MCP》2004,3(7):715-728
We have carried out a comprehensive characterization of human bile to define the bile proteome. Our approach involved fractionation of bile by one-dimensional gel electrophoresis and lectin affinity chromatography followed by liquid chromatography tandem mass spectrometry. Overall, we identified 87 unique proteins, including several novel proteins as well as known proteins whose functions are unknown. A large majority of the identified proteins have not been previously described in bile. Using lectin affinity chromatography and enzymatically labeling of asparagine residues carrying glycan moieties by (18)O, we have identified a total of 33 glycosylation sites. The strategy described in this study should be generally applicable for a detailed proteomic analysis of most body fluids. In combination with "tagging" approaches for differential proteomics, our method could be used for identification of cancer biomarkers from any body fluid. 相似文献