Cytopathology of Tomato torrado virus Infection in Tomato and Nicotiana benthamiana

Electron microscopy studies were carried out to investigate the cytopathological changes induced in tomato leaves by Tomato torrado virus (ToTV) that infects tomato plants worldwide causing severe necrotic symptoms. Plants infected with one of the Polish isolates of ToTV were used for cytopathological research. The results revealed severe cellular alterations, especially in Solanum lycopersicum. Moreover, it was shown that crystalline aggregates of virions occurred not only within the phloem cells as it has been previously reported.     

Single,Double and Quadruple Alanine Substitutions at Oligomeric Interfaces Identify Hydrophobicity as the Key Determinant of Human Neutrophil Alpha Defensin HNP1 Function

HNP1 is a human alpha defensin that forms dimers and multimers governed by hydrophobic residues, including Tyr¹⁶, Ile²⁰, Leu²⁵, and Phe²⁸. Previously, alanine scanning mutagenesis identified each of these residues and other hydrophobic residues as important for function. Here we report further structural and functional studies of residues shown to interact with one another across oligomeric interfaces: I20A-HNP1 and L25A-HNP1, plus the double alanine mutants I20A/L25A-HNP1 and Y16A/F28A-HNP1, and the quadruple alanine mutant Y16A/I20A/L25A/F28A-HNP1. We tested binding to HIV-1 gp120 and HNP1 by surface plasmon resonance, binding to HIV-1 gp41 and HNP1 by fluorescence polarization, inhibition of anthrax lethal factor, and antibacterial activity using the virtual colony count assay. Similar to the previously described single mutant W26A-HNP1, the quadruple mutant displayed the least activity in all functional assays, followed by the double mutant Y16A/F28A-HNP1. The effects of the L25A and I20A single mutations were milder than the double mutant I20A/L25A-HNP1. Crystallographic studies confirmed the correct folding and disulfide pairing, and depicted an array of dimeric and tetrameric structures. These results indicate that side chain hydrophobicity is the critical factor that determines activity at these positions.     

House dust mite extract activates apical Cl− channels through protease‐activated receptor 2 in human airway epithelia

Adequate fluid secretion from airway mucosa is essential for maintaining mucociliary clearance, and fluid hypersecretion is a prominent feature of inflammatory airway diseases such as allergic rhinitis. House dust mite extract (HDM) has been reported to activate protease‐activated receptors (PARs), which play various roles in airway epithelia. However, the role of HDM in regulating ion transporters and fluid secretion has not been investigated. We examined the effect of HDM on ion transport in human primary nasal epithelial cells. The Ca²⁺‐sensitive dye Fura2‐AM was used to determine intracellular Ca²⁺ concentration ([Ca²⁺]_i) by means of spectrofluorometry in human normal nasal epithelial cells (NHNE). Short‐circuit current (Isc) was measured using Ussing chambers. Fluid secretion from porcine airway mucosa was observed by optical measurement. HDM extract (10 µg/Ml) effectively cleaved the PAR‐2 peptide and induced an increase of [Ca²⁺]_i that was abolished by desensitization with trypsin, but not with thrombin. Apical application of HDM‐induced Isc sensitive to both a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor and a Ca²⁺‐activated Cl^? channel (CaCC) inhibitor. HDM extract also stimulated fluid secretion from porcine airway mucosa. HDM extract activated PAR‐2 and apical Cl^? secretion via CaCC and CFTR, and HDM‐induced fluid secretion in porcine airway mucosa. Our results suggest a role for PAR‐2 in mucociliary clearance and fluid hypersecretion of airway mucosa in response to air‐borne allergens such as HDM. J. Cell. Biochem. 109: 1254–1263, 2010. © 2010 Wiley‐Liss, Inc.     

妊娠相关脑卒中39 例临床分析

目的:探讨妊娠相关脑卒中的发病原因、临床表现、母婴结局、治疗及预防措施。方法:回顾性分析2001年1月-2013年12月我院共收治的妊娠相关脑卒中39例患者的临床资料。结果:39例患者中,发生在妊娠期21例,产褥期18例。经电子计算机断层扫描(CT)、磁共振成像(MRI)、磁共振动脉血管造影(MRA)、磁共振脑静脉血管成像(MRV)、数字减影血管造影术(DSA)和腰椎穿刺等检查明确诊断,诊断出血性脑卒中7例,脑梗死3例,脑静脉窦血栓(CVST)29例,均给予相应的抢救及治疗。16例早期、中期妊娠患者行人工流产术或利凡诺羊膜腔内注射穿刺引产终止妊娠,5例患者行剖宫产终止妊娠。患者治愈出院15例,6例死亡,14例遗留不同程度的肢体活动障碍或语言障碍,家属放弃治疗出院4例。结论:妊娠相关脑卒中危险因素主要包括子痫前期、心源性栓塞、脑血管畸形、脑动脉瘤、水电解质紊乱等代谢障碍性疾病及产褥感染等。其发病急、病死率高,故需提高对本病的认识,定期产前检查,及时发现高危因素,早诊断及时治疗,选择适当的时机及方式终止妊娠是改善妊娠相关脑卒中患者预后的关键。     

Transforming growth factor-β1 suppresses hepatitis B virus replication by the reduction of hepatocyte nuclear factor-4α expression

Several studies have demonstrated that cytokine-mediated noncytopathic suppression of hepatitis B virus (HBV) replication may provide an alternative therapeutic strategy for the treatment of chronic hepatitis B infection. In our previous study, we showed that transforming growth factor-beta1 (TGF-β1) could effectively suppress HBV replication at physiological concentrations. Here, we provide more evidence that TGF-β1 specifically diminishes HBV core promoter activity, which subsequently results in a reduction in the level of viral pregenomic RNA (pgRNA), core protein (HBc), nucleocapsid, and consequently suppresses HBV replication. The hepatocyte nuclear factor 4alpha (HNF-4α) binding element(s) within the HBV core promoter region was characterized to be responsive for the inhibitory effect of TGF-β1 on HBV regulation. Furthermore, we found that TGF-β1 treatment significantly repressed HNF-4α expression at both mRNA and protein levels. We demonstrated that RNAi-mediated depletion of HNF-4α was sufficient to reduce HBc synthesis as TGF-β1 did. Prevention of HNF-4α degradation by treating with proteasome inhibitor MG132 also prevented the inhibitory effect of TGF-β1. Finally, we confirmed that HBV replication could be rescued by ectopic expression of HNF-4α in TGF-β1-treated cells. Our data clarify the mechanism by which TGF-β1 suppresses HBV replication, primarily through modulating the expression of HNF-4α gene.     

Post‐activation treatment with demecolcine improves development of somatic cell nuclear transfer embryos in pigs by modifying the remodeling of donor nuclei

The objective of this study was to examine the effect of cytochalasin B (CB) and/or demecolcine (Dc) on the remodeling of donor nuclei, nuclear ploidy, and development of somatic cell nuclear transfer (SCNT) and parthenogenetic (PA) pig embryos. SCNT and PA oocytes were either untreated (control), or treated with CB, Dc, or both CB and Dc after electric activation, and then cultured or transferred to surrogates. In SCNT, blastocyst formation was higher after treatment with CB and/or Dc (26–28%) than in the controls (16%). The number of oocytes that formed a single pronucleus (PN) was higher after treatment with Dc (86%) and CB + Dc (86%) than under control conditions (44%) or after treatment with CB (63%). In PA, blastocyst formation was higher after CB treatment (47%) than under control conditions (28%), while the formation of a single PN was higher after treatment with Dc (88%) and CB + Dc (84%) compared to controls (34%). The rate of formation of diploid embryos was higher after treatment with Dc and CB + Dc than under control conditions. Dc treatment resulted in a farrowing rate of 50% with 1.1% production efficiency, while controls showed a farrowing rate of 37.5% and a production efficiency of 0.7%. The results of our study demonstrate that post‐activation treatment with Dc improves preimplantation development and supports normal in vivo development of SCNT pig embryos, probably because Dc induces formation of a single PN and this leads to normal nuclear ploidy. Mol. Reprod. Dev. 76: 611–619, 2009. © 2008 Wiley‐Liss, Inc.     

Well-defined linear Au<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> (<Emphasis Type="Italic">n</Emphasis> = 2–4) chains encapsulated in SWCNTs: a DFT study

One-dimensional (1D) gold nanostructures have been extensively studied due to their potential applications in nanoelectronic devices. Using first-principles calculations, composites consisting of a well-defined linear Au _n (n?=?2–4) chain encapsulated in a (9,0) single-walled carbon nanotube (SWCNT) were studied. The translational energy barrier of a single Au atom in a (9,0) SWCNT was found to be 0.03 eV. This low barrier guaranteed the formation of Au _n @ (9,0) SWCNT (n?=?1–4) composites. Bond lengths, differential charge densities, and electronic band structures of the composites were studied. The average Au–Au bond lengths in the composites were found to be almost the same as those in the corresponding free-standing linear Au _n . The average bond length increased as the number of Au atoms increased. Charge transfer in all of these composites was slight, although a few valence electrons were transferred from the (9,0) SWCNT and the Au chains to intercalations. The conductivities of the encapsulated linear Au _n (n?=?2–4) chains were enhanced to some extent by encapsulating them in the SWCNT.