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Biomedical subjects

Jianyang Xu

Publications and source records attributed to Jianyang Xu.

4 recordsLinked to original sources

Characterization of an early gene (wsv477) from shrimp white spot syndrome virus (WSSV).

White spot syndrome virus (WSSV) is one of the most virulent pathogens causing high mortality in shrimp. The viral early genes play a key role in DNA replication and virus proliferation. In this study, a WSSV gene (wsv477) encoding 208 amino acid peptides was characterized as an early gene. The temporal analysis showed that the wsv477 gene was first transcribed at 4 h post-infection, suggesting that it was an early gene. The wsv477 gene was expressed in Escherichia coli and purified. Subsequently the specific antibody was raised using the purified fusion protein (GST-WSV477). Western blot revealed that the wsv477 gene was expressed at 6 h post-infection in vivo. As indicated by GTP-binding assay, the WSV477 protein had GTP-binding activity.

Amino Acid Sequence↗

Silencing shrimp white spot syndrome virus (WSSV) genes by siRNA.

White spot syndrome virus (WSSV) is a major shrimp pathogen causing large economic losses all over the world. So far, however, there is no efficient approach to control this virus. RNA interference (RNAi), which has been applied to silence virus genes in eukaryotic organisms. In this investigation, a specific 21bp short interfering RNA (vp28-siRNA) targeting a major envelope protein gene (vp28) of WSSV was used to induce gene silencing in vivo in Penaeus japonicus shrimp. It was found that the transcription and expression of vp28 gene were silenced by the sequence-specific vp28-siRNA. However, the RNAi effect disappeared or significantly weakened even if one-nucleotide mutation existed in the vp28-siRNA. As revealed by quantitative PCR, the vp28-siRNA caused a significant reduction in viral DNA production of WSSV-infected shrimp. When treated with the vp28-siRNA, WSSV-infected shrimp had a reduced mortality rate. After three injections of the vp28-siRNA, the virus was completely eradicated from WSSV-infected shrimp. These findings suggest that RNAi is capable of silencing sequence-specific genes of WSSV and might constitute a new therapeutic strategy for WSSV infection in shrimp.

Animals↗

Changes in FMRI in the human brain related to different durations of manual acupuncture needling.

OBJECTIVES: The present study is aimed at evaluating the effects of manual acupuncture with different durations on the human brain using functional magnetic resonance imaging. MATERIALS AND METHODS: Eighteen healthy right-handed volunteers were divided into three groups randomly. Each group received only one kind of acupuncture on the right LI4 (Hegu) point, which lasted 30 sec, 60 sec, or 180 sec, respectively. Fix-effect and conjunction analysis were used to compare the effects of the three kinds of acupunctures. RESULTS: The results indicated that the stimulation of manual acupuncture with different durations could induce different effects in the central nervous system on the human brain. The longer duration of manual acupuncture might induce more significant areas. CONCLUSIONS: The present study provided not only neuroimaging evidence for manual acupuncture, but also a useful guide for clinical applications of acupuncture. In addition, the results might be helpful to understand the relationship between the central nervous system responses and the durations of acupuncture.

Acupuncture Points↗

Acupoint-specific fMRI patterns in human brain.

Specific central nervous system (CNS) responses to acupuncture have recently attracted attention. It is important to understand the differences in fMRI images of the brain evoked by acupuncture at an acupoint and at a nearby "sham" point. Here, we report analyses of fMRI images of the brains of 37 healthy volunteers in response to acupuncture at Liv3 (Taichong) and LI4 (Hegu) versus their sham points. We found common activation areas in response to Liv3 or LI4 acupuncture in the middle temporal gyrus and cerebellum, along with deactivation areas in the middle frontal gyrus and inferior parietal lobule, compared with the effects of acupuncture at sham points. Acupuncture at Liv3 evoked specific activation at the postcentral gyrus, posterior cingulate, parahippocampal gyrus, BA 7, 19 and 41, but deactivation at the inferior frontal gyrus, anterior cingulate, BA 17 and 18, compared with acupuncture at its sham point. Acupuncture at LI4 evoked specific activation at the temporal pole, but deactivation at the precentral gyrus, superior temporal gyrus, pulvinar and BA 8, 9 and 45, compared with acupuncture at its sham point. These observations reveal that acupuncture at acupoints induces specific patterns of brain activity, and these patterns may relate to the therapeutic effects of acupuncture.

Acupuncture↗