3,457 research outputs found

    3,6-Dichloro-N-(4,6-dichloro­pyrimidin-2-yl)picolinamide

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    In the title compound, C10H4Cl4N4O, the pyridine and pyrimidine rings are nearly perpendicular to each other, the dihedral angle between them being 86.60 (10)°. In the crystal structure, the N and O atoms in the amide group are involved in inter­molecular hydrogen bonds, forming a one-dimensional chain along the c axis

    Polarization-based probabilistic discriminative model for quantitative characterization of cancer cells

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    We propose a polarization-based probabilistic discriminative model for deriving a set of new sigmoid-transformed polarimetry feature parameters, which not only enables accurate and quantitative characterization of cancer cells at pixel level, but also accomplish the task with a simple and stable model. By taking advantages of polarization imaging techniques, these parameters enable a low-magnification and wide-field imaging system to separate the types of cells into more specific categories that previously were distinctive under high magnification. Instead of blindly choosing the model, the L0 regularization method is used to obtain the simplified and stable polarimetry feature parameter. We demonstrate the model viability by using the pathological tissues of breast cancer and liver cancer, in each of which there are two derived parameters that can characterize the cells and cancer cells respectively with satisfactory accuracy and sensitivity. The stability of the final model opens the possibility for physical interpretation and analysis. This technique may bypass the typically labor-intensive and subjective tumor evaluating system, and could be used as a blueprint for an objective and automated procedure for cancer cell screening

    Detection of neural connections with ex vivo MRI using a ferritin-encoding trans-synaptic virus

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    The elucidation of neural networks is essential to understanding the mechanisms of brain functions and brain disorders. Neurotropic virus-based trans-synaptic tracing tools have become an effective method for dissecting the structure and analyzing the function of neural-circuitry. However, these tracing systems rely on fluorescent signals, making it hard to visualize the panorama of the labeled networks in mammalian brain in vivo. One MRI method, Diffusion Tensor Imaging (DTI), is capable of imaging the networks of the whole brain in live animals but without information of anatomical connections through synapses. In this report, a chimeric gene coding for ferritin and enhanced green fluorescent protein (EGFP) was integrated into Vesicular stomatitis virus (VSV), a neurotropic virus that is able to spread anterogradely in synaptically connected networks. After the animal was injected with the recombinant VSV (rVSV), rVSV-Ferritin-EGFP, into the somatosensory cortex (SC) for four days, the labeled neural-network was visualized in the postmortem whole brain with a T2-weighted MRI sequence. The modified virus transmitted from SC to synaptically connected downstream regions. The results demonstrate that rVSV-Ferritin-EGFP could be used as a bimodal imaging vector for detecting synaptically connected neural-network with both ex vivo MRI and fluorescent imaging. The strategy in the current study has the potential to longitudinally monitor the global structure of a given neural-network in living animals

    Characteristic gene expression profiles in the progression from liver cirrhosis to carcinoma induced by diethylnitrosamine in a rat model

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    <p>Abstract</p> <p>Background</p> <p>Liver cancr is a heterogeneous disease in terms of etiology, biologic and clinical behavior. Very little is known about how many genes concur at the molecular level of tumor development, progression and aggressiveness. To explore the key genes involved in the development of liver cancer, we established a rat model induced by diethylnitrosamine to investigate the gene expression profiles of liver tissues during the transition to cirrhosis and carcinoma.</p> <p>Methods</p> <p>A rat model of liver cancer induced by diethylnitrosamine was established. The cirrhotic tissue, the dysplasia nodules, the early cancerous nodules and the cancerous nodules from the rats with lung metastasis were chosen to compare with liver tissue of normal rats to investigate the differential expression genes between them. Affymetrix GeneChip Rat 230 2.0 arrays were used throughout. The real-time quantity PCR was used to verify the expression of some differential expression genes in tissues.</p> <p>Results</p> <p>The pathological changes that occurred in the livers of diethylnitrosamine-treated rats included non-specific injury, fibrosis and cirrhosis, dysplastic nodules, early cancerous nodules and metastasis. There are 349 upregulated and 345 downregulated genes sharing among the above chosen tissues when compared with liver tissue of normal rats. The deregulated genes play various roles in diverse processes such as metabolism, transport, cell proliferation, apoptosis, cell adhesion, angiogenesis and so on. Among which, 41 upregulated and 27 downregulated genes are associated with inflammatory response, immune response and oxidative stress. Twenty-four genes associated with glutathione metabolism majorly participating oxidative stress were deregulated in the development of liver cancer. There were 19 members belong to CYP450 family downregulated, except CYP2C40 upregulated.</p> <p>Conclusion</p> <p>In this study, we provide the global gene expression profiles during the development and progression of liver cancer in rats. The data obtained from the gene expression profiles will allow us to acquire insights into the molecular mechanisms of hepatocarcinogenesis and identify specific genes (or gene products) that can be used for early molecular diagnosis, risk analysis, prognosis prediction, and development of new therapies.</p

    Simple method to prepare DNA templates from a slice of peanut cotyledonary tissue for Polymerase Chain Reaction

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    An efficient DNA extraction method was developed for peanut seed, where only 3-5 mg cotyledonary tissue was enough for more than 50 PCR reactions with a reaction volume of 15 \u3bcl. Both low copy number and high copy number DNA sequences were successfully amplified. Processing one seed sample only took about half an hour. Sampling had no significant effects on germination and development. The DNA extraction method makes it possible to identify transformants and conduct molecular marker studies prior to sowing, and thus may greatly hasten research progress

    Sodium azide mutagenesis resulted in a peanut plant with elevated oleate content

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    Screening of peanut seeds resulting from 0.39% sodium azide treatment with NIRS calibration equation for bulk seed samples identified a plant with more than 60% oleate. Oleate content in individual seeds of the plant, as predicted by NIRS calibration equation for intact single peanut seeds, ranged from 50.05% ~ 68.69%. Three seeds with &gt;60% oleate thus identified were further confirmed by gas chromatography. Multiple sequence alignments of the FAD2B gene from Huayu 22 (wild type) and peanut seeds with elevated oleate (mutant type) revealed a C281T transition in the coding region causing an I94T substitution in the oleoyl-PC desaturase, which may be responsible for reduction in the enzyme activity

    Novel protocol to identify true hybrids in normal oleate x high oleate crosses in peanut

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    A novel hybrid identification protocol was developed for F0:1 peanut seeds resulting from crosses between normal oleate cultivars with wild type FAD2B gene and high oleate genotypes with an A insertion in FAD2B gene. Presence of a series of overlapped peaks in trace file of the PCR product amplified with bF19/R1 primers was an indication of hybridity. This protocol may facilitate high oleate breeding and genetic studies in peanut
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