307 research outputs found

    Isolated angiitis of the central nervous system with tumor-like lesion, mimicking brain malignant glioma: a case report and review of the literature

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    <p>Abstract</p> <p>Background</p> <p>Isolated angiitis of the central nervous system (IACNS) is a rare but severe vascular disease, which could present like an isolated inflammatory lesion on magnetic resonance imaging (MRI). To date, only a few such cases with tumor-like IACNS have been reported.</p> <p>Case Presentation</p> <p>A 35-year-old woman presented with headache and left-sided weakness. MRI scans initially mislead us to a diagnosis of glioblastoma (GBM). Surgery was performed. The mass was sub-totally resected. Pathological examination confirmed a cerebral vasculitis. Radiological features, such as disproportionate mass effect, striped hemorrhage and abnormal enhancement of adjacent vessels, could be helpful to distinguish a tumor-like IACNS from a GBM. Single therapy with high doses of steroid did not improve the patient's condition. Combined therapy with prednisolone and cyclophosphamide showed great benefit to the patient. No relapse occurred during the period of 18 months follow-up.</p> <p>Conclusions</p> <p>Although a tumor-like IACNS has no established imaging features, a diagnosis of tumor-like IACNS should be suspected when MRI shows inappropriate presentations of a tumor. Greater awareness of this potential manifestation of IACNS may facilitate more prompt diagnosis and treatment.</p

    Leveraging Multi-level Dependency of Relational Sequences for Social Spammer Detection

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    Much recent research has shed light on the development of the relation-dependent but content-independent framework for social spammer detection. This is largely because the relation among users is difficult to be altered when spammers attempt to conceal their malicious intents. Our study investigates the spammer detection problem in the context of multi-relation social networks, and makes an attempt to fully exploit the sequences of heterogeneous relations for enhancing the detection accuracy. Specifically, we present the Multi-level Dependency Model (MDM). The MDM is able to exploit user's long-term dependency hidden in their relational sequences along with short-term dependency. Moreover, MDM fully considers short-term relational sequences from the perspectives of individual-level and union-level, due to the fact that the type of short-term sequences is multi-folds. Experimental results on a real-world multi-relational social network demonstrate the effectiveness of our proposed MDM on multi-relational social spammer detection

    Differential expression of miRNAs related to caste differentiation in the honey bee, Apis mellifera

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    International audienceAbstractHoney bees are very important eusocial insects and are involved in the pollination of many plants. Queen bees and worker bees can develop from the same fertilized eggs and are thus genetically identical despite their substantial behavioral and physiological differences. The mechanism governing developmental differences between worker and queen bees has always attracted much interest. While there are several reports on messenger RNA (mRNA) expression related to caste differentiation or microRNA (miRNA) expression in one time point of caste differentiation, no systematic investigation of the dynamic expression of small RNAs along with these two caste development has, thus far, been carried out. In this study, we present the dynamic expression profiles of queen and worker bee small RNAs and show caste-specific miRNA expression patterns between them, indicating that miRNAs may be related to the differential development of worker and queen bee larvae. Results presented here will make a valuable contribution to understanding of the caste switch between worker and queen bees

    Molecular Cloning and Characterization of Juvenile Hormone Acid Methyltransferase in the Honey Bee, Apis mellifera, and Its Differential Expression during Caste Differentiation

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    Juvenile hormone acid methyltransferase (JHAMT) is an enzyme involved in one of the final steps of juvenile hormone biosynthesis in insects. It transfers a methyl group from S-adenosyl-L-methionine (SAM) to the carboxyl group of either farnesoic acid (FA) or JH acid (JHA). Several genes coding for JHAMT have been cloned and characterized from insects from different orders, and they have been shown to play critical roles in metamorphosis and reproduction. However, the significance of JHAMT in Hymenopteran insects is unknown. We used RACE amplification method to clone JHAMT cDNA from the honey bee, Apis mellifera (AmJHAMT). The full length cDNA of AmJHAMT that we cloned is 1253bp long and encodes a 278-aa protein that shares 32-36% identity with known JHAMTs. A SAM-binding motif, conserved in the SAM-dependent methyltransferase (SAM-MT) superfamily, is present in AmJHAMT. Its secondary structure also contains a typical SAM-MT fold. Most of the active sites bound with SAM and substrates (JHA or FA) are conserved in AmJHAMT as in other JHAMT orthologs. Phylogenetic analysis clustered AmJHAMT with the other orthologs from Hymenoptera to form a major clade in the phylogenetic tree. Purified recombinant AmJHAMT protein expressed in E. coli was used to produce polyclonal antibodies and to verify the identity of AmJHAMT by immunoblotting and mass spectrometry. Quantitative RT-PCR and immunoblotting analyses revealed that queen larvae contained significantly higher levels of AmJHAMT mRNA and protein than worker larvae during the periods of caste development. The temporal profiles of both AmJHAMT mRNA and protein in queens and workers showed a similar pattern as the JH biosynthesis. These results suggest that the gene that we cloned codes for a functional JHAMT that catalyzes the final reactions of JH biosynthesis in honey bees. In addition, AmJHAMT may play an important role in honey bee caste differentiation.The research was supported by the earmarked funds for Modern Agro-industry Technology Research System (No.CARS-45-KXJ3) and National Natural Science Foundation of China (No.30571409) to SKS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Viral Infection Affects Sucrose Responsiveness and Homing Ability of Forager Honey Bees, Apis mellifera L

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    Honey bee health is mainly affected by Varroa destructor, viruses, Nosema spp., pesticide residues and poor nutrition. Interactions between these proposed factors may be responsible for the colony losses reported worldwide in recent years. In the present study, the effects of a honey bee virus, Israeli acute paralysis virus (IAPV), on the foraging behaviors and homing ability of European honey bees (Apis mellifera L.) were investigated based on proboscis extension response (PER) assays and radio frequency identification (RFID) systems. The pollen forager honey bees originated from colonies that had no detectable level of honey bee viruses and were manually inoculated with IAPV to induce the viral infection. The results showed that IAPV-inoculated honey bees were more responsive to low sucrose solutions compared to that of non-infected foragers. After two days of infection, around 10⁷ copies of IAPV were detected in the heads of these honey bees. The homing ability of IAPV-infected foragers was depressed significantly in comparison to the homing ability of uninfected foragers. The data provided evidence that IAPV infection in the heads may enable the virus to disorder foraging roles of honey bees and to interfere with brain functions that are responsible for learning, navigation, and orientation in the honey bees, thus, making honey bees have a lower response threshold to sucrose and lose their way back to the hive.This study was supported by earmarked funds for Modern Agro-industry Technology Research System (No. CARS-45-KXJ3), Nature and Science Foundation Commission of Zhejiang Province (R3080306) to SKS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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