Magnonic Unidirectional Spin Hall Magnetoresistance in a Heavy-Metal-Ferromagnetic-Insulator Bilayer.

We report the observation of the unidirectional spin Hall magnetoresistance (USMR), which depends on the current or magnetization direction, in heavy-metal-ferromagnetic-insulator bilayer, Pt-Y_{3}Fe_{5}O_{12} (YIG). This USMR is apparently not caused by the mechanisms established in metallic bilayer, in which the ferromagnetic layer is required to be electrically conductive. From the magnetic field, current, temperature, and YIG thickness dependent measurements, the USMR is attributed to the asymmetric magnon creation and annihilation induced by the spin-orbit torque. This asymmetry and the resultant USMR are further revealed by the micromagnetic simulations combined with the spin-orbit torque and the spin drift-diffusion model. Our finding exhibits a nonlinear manipulation of magnons with the charge current.

Alprostadil alleviates liver injury in septic rats via TLR4/NF-κB pathway.

OBJECTIVE: The aim of this study was to explore the role of alprostadil (Alp) in cecal ligation and puncture (CLP)-induced septic injury in rats and its possible mechanism of action. MATERIALS AND METHODS: Wistar rats were randomly assigned into three groups, including: Sham group (no CLP was performed), CLP group (CLP was conducted) and Alp group (Alp was injected after CLP). Serum liver function markers, pathological changes in liver tissues, alterations in the level of oxidative stress, activity of the Toll-like receptor 4 (TLR4)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, and release of inflammatory factor tumor necrosis factor alpha (TNF-α) in the liver tissue homogenate were detected in each group. RESULTS: Compared with Sham group, the rats in CLP group had substantially elevated content of serum liver function markers, increased apoptotic liver cells, upregulated levels of oxidative stress, enhanced activity of the TLR4/NF-κB pathway, and increased release of TNF-α (p<0.05). Meanwhile, there were evident pathological changes under microscopic examination in CLP group compared with Sham group (p<0.05). In comparison with CLP group, Alp group exhibited significantly decreased concentrations of liver function markers, microscopic findings, such as decreased inflammatory cell infiltration in the interstitum, notably lowered proportion of apoptotic cells, decreased level of oxidative stress, weakened activity of the TLR4/NF-κB pathway and restrained release of TNF-α (p<0.05). Furthermore, normal morphology of liver cells was observed in Alp group compared with CLP group (p<0.05). CONCLUSIONS: Alp alleviates liver injury in septic rats by inhibiting the TLR4/NF-κB pathway.

Direct visualization of the novel pathogen, Spiroplasma eriocheiris, in the freshwater crayfish Procambarus clarkii (Girard) using fluorescence in situ hybridization.

Spiroplasma eriocheiris is the first spiroplasma strain known to be pathogenic to freshwater crustaceans. It has caused considerable economic losses both in the freshwater crayfish Procambarus clarkii (Girard) and in some other crustaceans. The monitoring of the pathogen in crustacean populations and study of its behaviour in the laboratory require the development of reliable diagnostic tools. In this article, we improved microscopic identification of S. eriocheiris by combining in situ hybridization with specific fluorescently labelled oligonucleotide probes. The established fluorescence in situ hybridization (FISH) allowed simultaneous visualization, identification and localization of S. eriocheiris in the tissues of diseased crayfish P. clarkii and exhibited low background autofluorescence and ideal signal-to-noise ratio. With the advantages of better tissue penetration, potentially more specific and stable, we designed three species-specific oligonucleotide probes utilizing the sequences of 16S-23S rRNA intergenic spacer regions (ISRs) of S. eriocheiris. Positive hybridization signals were visualized in haemocytes and connective tissues of hepatopancreas, cardiac muscle and gill from diseased crayfish. This unique distribution pattern matched the pathological changes when diagnosed by H&E staining and indicated that S. eriocheiris probably spread throughout the tissues in P. clarkii by hemokinesis. This assay will facilitate our understanding of the pathogenesis of S. eriocheiris and enhance the early diagnosis of the novel pathogen.

[Study on the genetic variations of the major neutralization antigen VP7 of group A rotavirus type G1 in China].

OBJECTIVE: To study the genetic variations of the major neutralization antigen VP7 of group A rotavirus, type G1 in China. METHODS: Twenty-three isolates derived from seven cities (Beijing, Shenyang, Xinxiang, Shanghai, Shenzhen, Guangzhou and Chongqing) during the period of 1988-1998 were analyzed for the VP7 cDNA sequences. RESULTS: An obvious homology was observed in amino acid sequences of VP7 in the 23 isolates. Compared with the standard strain Wa, the variations were found at the position of aa 41, 49, 57, 65, 68, 74, 94, 97, 147, 170, 217, 218, 268, 281 and 291, respectively, and all of these were located in the variable region(VR)3,4,5,7,8 as well as in the C-terminal of the peptide. There seemed to be no remarkable divergence among the samples collected from different cities and all of them shared the same genetic lineage with the strain Jpn-417, though there might be one or two amino acid substitutions as time passed. When detected simultaneously with ELISA using G1 serotype-specific monoclonal antibody, the location of amino acid 91 was found presumably related to the neutralization epitope in VP7 of the type G1. Variations at some position may be resulted in the change of electropherotype. CONCLUSIONS: The results indicated that the recent isolates with representative genetic and antigenic features should be used to develop effective vaccines, and the antigenic variations should be monitored periodically.

[The detection of pediatric mycoplasma pneumonia cases by polymerase chain reaction and it's clinical significance].

Mycoplasma DNA in nasopharynx secretion from seventy pediatric mycoplasma cases was detected, using rapid feit of PCR DNA sample preparation method and simple PCR processes. The result of PCR showed that: fifty-three positive cases with a positive rate 75.7%, comparing with only 53.8% positive rate using mycoplasma culture method (P < 0.05). Thirteen PCR positive patients were treated by Venoclysis Erythromycin for 10-14 days but mycoplasma DNA was identified by PCR again. Among them, eight cases turned negative, but five cases still remained positive. The resalt showed that this method was not only more sensitive and reliable than conventional culture techniques, but also could simplify the PCR processes. It could be used for routine mycoplasma pneumonia test and for early diagnosis, which leads to early treatment and evaluation of therapeufic effect.

[Diagnosis of endomyocardial fibrosis with endomyocardial biopsy].

Ten cases of endomyocardial fibrosis (EMF) were diagnosed with angiocardiography in showing a huge right atrium' tricuspid regurgitation and obliteration of right ventricular apex. The diagnosis was confirmed in 9 of them pathologically after right ventricular endomyocardial biopsy (EMB) in showing striking thickening of endocardium with presence of fibrosis. The remaining case was not confirmed with EMB. It is concluded that EMB is a quite useful method in the diagnosis of EMF. The cause of misdiagnosis in the tenth case was discussed.

Cloning and restriction mapping of human HBV genome serotype adr.

A Bam HI cleaved 3.2 Kb fragment from the HBV adr genome was cloned in E. coli using pBR322 as vector. Sixteen restriction sites from the action of Bam HI, Hind III, Bgl I, Bgl II, Ava I, Hinc II, Sph I, Xba I, Xho I and Sst II were determined and mapped. No cleavage sites were found for Eco RI, Pst I, Sma I, Hpa I, Kpn I, Pvu II and Sst I. The restriction map for HBV adr is significantly different from those reported for the subtypes adw, ayw and adyw.