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The genus Nanhuaphasma Chen, He & Li, 2002 was established as a member of the family Pseudophasmatidae Rehn, 1904 (now belonging to Aschiphasmatidae Brunner von Wattenwyl, 1893) based on the male of N.hamicercum Chen & He, 2002. We review the status of Nanhuaphasma and N.hamicercum by examining the holotype and male and female non-types which were collected in same location as the holotype. We find that Nanhuaphasma is a junior synonym of Dajaca Brunner von Wattenwyl, 1893 and N.hamicercum is a junior synonym of D.napolovi Brock, 2000. Complementing egg morphology of D.napolovi and keys to eight species of Dajaca are provided.
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The SARS-CoV-2 Omicron variant exhibits striking immune evasion and is spreading globally at an unprecedented speed. Understanding the underlying structural basis of the high transmissibility and greatly enhanced immune evasion of Omicron is of high importance. Here through cryo-EM analysis, we present both the closed and open states of the Omicron spike, which appear more compact than the counterparts of the G614 strain, potentially related to the Omicron substitution induced enhanced protomer-protomer and S1-S2 interactions. The closed state showing dominant population may indicate a conformational masking mechanism of immune evasion for Omicron spike. Moreover, we capture two states for the Omicron S/ACE2 complex with S binding one or two ACE2s, revealing that the substitutions on the Omicron RBM result in new salt bridges/H-bonds and more favorable electrostatic surface properties, together strengthened interaction with ACE2, in line with the higher ACE2 affinity of the Omicron relative to the G614 strain. Furthermore, we determine cryo-EM structures of the Omicron S/S3H3 Fab, an antibody able to cross-neutralize major variants of concern including Omicron, elucidating the structural basis for S3H3-mediated broad-spectrum neutralization. Our findings shed new lights on the high transmissibility and immune evasion of the Omicron variant and may also inform design of broadly effective vaccines against emerging variants.
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The recent outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid international spread pose a global health emergency. The trimeric spike (S) glycoprotein interacts with its receptor human ACE2 to mediate viral entry into host-cells. Here we present cryo-EM structures of an uncharacterized tightly closed SARS-CoV-2 S-trimer and the ACE2-bound-S-trimer at 2.7-Å and 3.8-Å-resolution, respectively. The tightly closed S-trimer with inactivated fusion peptide may represent the ground prefusion state. ACE2 binding to the up receptor-binding domain (RBD) within S-trimer triggers continuous swing-motions of ACE2-RBD, resulting in conformational dynamics of S1 subunits. Noteworthy, SARS-CoV-2 S-trimer appears much more sensitive to ACE2-receptor than SARS-CoV S-trimer in terms of receptor-triggered transformation from the closed prefusion state to the fusion-prone open state, potentially contributing to the superior infectivity of SARS-CoV-2. We defined the RBD T470-T478 loop and residue Y505 as viral determinants for specific recognition of SARS-CoV-2 RBD by ACE2, and provided structural basis of the spike D614G-mutation induced enhanced infectivity. Our findings offer a thorough picture on the mechanism of ACE2-induced conformational transitions of S-trimer from ground prefusion state towards postfusion state, thereby providing important information for development of vaccines and therapeutics aimed to block receptor binding.Competing Interest StatementThe authors have declared no competing interest.View Full Text
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Temporins are a kind of small,hydrophobic and C-terminus amidated antimicrobial peptides from Rana species.They are effective against bacteria,fungi,yeast,protozoa and viruses.Two novel temporins named as temporin-La(LLRHWKILEKYLanifc) and temporin-Lb(LFRHVVKIFEK.Ylamid.) were cloned from Lithobates catesbeianus.Synthetic peptides of temporin-La and temporin-Lb showed strong antimicrobial activities against bacteria tested,especially Gram-positive bacteria.Besides,temporin-La showed no haemolytic activity to rabbit erythrocytes at the concentration of 250 mg/L while temporin-Lb showed weak haemolytic activity(LC50≈ 230 μmol/L).Transmission electron microscopy showed that temporin-La and temporin-Lb induced different effects on bacterial structure of Staphylococcus aureus.
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The susceptibility to 9 kinds of antibiotics of 393 animal pathogenic E. coli isolated from clinical samples was determined from 2000 to 2003. The resistance to TC, GM, CMP, AMP, RA, KM, FT, SM and CIP were 93.89%, 57.76%,78.63%, 77.86%, 92.11% ,47.33%, 46.82%, 76.84% and 74.81%, respectively. The isolates could be classified into eight classes according to the number of drugs to which srains were resistant. The resistance spectrum of the isolates varied from 2to 9 kinds of the above drugs. The strains that were resistant to seven kinds of drugs were more than 80 percent. The resistance rates of swine origin strains to GM,AMP and KM were higher than those of poultry origin strains, while the resistance rates of poultry origin strains to TC, CMP, SM and CIP were higher remarkably than those of swine origins. The frequency of resistance increased from 2000 to 2003,which was from 67.33% to 90.58% for CMP, 71.29% to 84.81% for AMP, 73.76%to 80.10% for SM and 61.88% to 88.48% for CIP. At the same time, the resistance rate of GM decreased from 61.39% to 53.92%. Thirty-seven strains (95 %) could make all the Kunming mice die within 72 h injected intraperitoneally with the culmice three times in vivo. The pathogenicity of wild strains with drug resistance acquired naturaly to mice did not decline.
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AIM To investigate the effect of OX-LDL and HMG- CoA reductase inhibitors simvastatin on PKC activity and cytosolic free Ca2+ in cultured human monocy tes. METHOD The activity of PKC was determined by its ability to tr ansfer phosphate from ［32P］ATP to lysine-rich histone and cytosolic free calcium［Ca2+］i was measured by flow cytometric analysis loading with the Ca2+ dye fluo3/Am. RESULTS OX-LDL increased PKC tot al activity in a dose-dependent manner with phase peaking at 12 min, then decre ased slowly and maintained for at least 20 min, while OX-LDL induced biphasic ［Ca2+］i responses including the rapid initial transient phase and the sustained phase. Removal of extracellular Ca2+ did not inhibit the rapid i nitial transient phase of OX-LDL-induced rise in ［Ca2+］i,but abolish ed the sustained phase of ［Ca2+］i response to OX-LDL. When simvastati n was added, the activity of PKC was markedly decreased and simvastatin did not impair the initial peak response to OX-LDL but significantly reduced the subseq uent plateau phase. CONCLUSION OX-LDL can significantly activate t he activity of PKC and elevate ［Ca2+］i in monocytes. The rapid initial transient phase was the result of mobilization of ［Ca2+］i from intrac ellular pool and sustained phase resulted from the influx of extracellular Ca 2+. The inhibition of PKC activity induced by simvastatin may be contribute to the changes of intracellular Ca2+.
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Objective: To investigate the effects of oxLDL and HMG-CoA reductase inhibitor simvastatin on PKC activity, and level of cytosol ic free Ca 2+ in cultured human umbilical vein endothelial cells. Methods: Th e activity of PKC was determined by its ability to transfer phosphate from 32P-ATP to lysine-rich histone and level of cytosolic free calcium［Ca2+ ］i was measured by flow cytometric analysis loading with the Ca2+ dye F luo-3/Am. Results: oxLDL increased PKC total activity in a dose-de pendent manner and peaked after 12 min, then decreased slowly and maintained for at least 30 min, while oxLDL induced biphasic ［Ca2+］i responses includ ing the rapid initial transient phase and the sustained phase. Removal of extrac ellular Ca2+ did not inhibit the rapid transient phase, but abolished the sustained phase. When simvastatin was added, the activity of PKC wasmarkedly dec reased with no impairment to the initial peak response, but significantly reduce d the sustained phase. Conclusion: oxLDL can induced dynamic changes of signal transduction of PKC and level of cytosolic free Ca2+ in HUVEC, these 2 events are closely linked. The change of rapid initial transient phase i s the result of mobilization of Ca2+ from intracellular pool and the chang e of sustained phase is from the influx of extracellular Ca2+. The inhibit ion of PKC activity induced by simvastatin may contribute to the changes of ［Ca 2+］i.
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AIM: To investigate effects of OX-LDL and VitE on the levels of IL-6,IL-8 and TNF-? in human umbilical vein endothelial cells(HUVEC). METHODS: Human umbilical vein endothelial cells were obtained by in vitro culture. HUVEC treated with or without Vit E was incubated with OX-LDL, and the levels of IL-6, IL-8 and TNF-? were determined by enzyme-linked immunosorbent assy technique. RESULTS:50 ?g/L,100 ?g/L, 200 ?g/L OX-LDL induced the release of IL-6,IL-8 and TNF-? by HUVEC in a dose-dependent manner. Compared with the control group , the levels of IL-6 and IL-8 were significantly increased at 6-12 h of stimulation with OX-LDL . Maximal levels of IL-6 and IL-8 occurred after 24-36 h, reaching a plateau maintained for at least 48 h. TNF-? rose after 2-6 h in HUVEC, and reached a maximum after 12 h. In contrast to IL-6 and IL-8, TNF-? declined after 48 h. However, when VitE (50 mg/L,100 mg/L,200 mg/L)was added, it can significant inhibited the release of IL-6, IL-8 and TNF-? in a dose-dependent manner, and after 48 h these cytokines have no diference between OX-LDL+VitE groups and OX-LDL groups. CONCLUSION: OX-LDL can obviously stimulate the production of IL-6,IL-8 and TNF-? in vascular endothelial cells, which can significantly be inhibited by VitE in a short time.
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AIM To investigate the effect of OX- LDL and HMG-CoA reductase inhibitors simvastatin on PKC activity and cytosolic free Ca2+ in cultured human monocytes. METHOD The activity of PKC was determined by its ability to transfer phosphate fm [32P] ATP to lysine-rich histone and cytosolic free calcium[Ca2+]i was measured by flow cytometric analysis loading with the Ca2+ dye fluo3/Am.RE- SULTS OX-LDL increased PKC total activity in a dose-dependent manner with phase peaking at 12 min, then decreased slowly and maintained for at least 20 min, while OX-LDL induced biphasic [Ca2+ ], responses including the rapid initial transient phase and the sustained phase. Removal of extracellular Ca2+ did not inhibit the rapid initial transient phase of OX-LDL-induced rise. in [ Ca2+ ]i, but abol- abolished the sustained phase of [ Ca2+ ] i response to OX LDL. When simvastatin was added, the activity of PKC was markedly decreased and simvastatin did not impair the initial peak response to OX-LDL but sig- nificantly reduced the subsequent plateau phase. CONCLUSION OX-LDL can significantly activate the activity of PKC and elevate [Ca2+ ]i in monocytes. The rapid initial transient phase was the result of mobilization of [Ca2+ ], fm intracellular pool and sustained phase resulted from the influx of extracellular Ca2+. The inhibition of PKC activity induced by simvastatin may be contribute to the changes of intracellular Ca2+.
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AMI: To clarify whether OX-LDL and simvastatin can induce the changes of PKC activity and cytosolic free Ca 2+ in rat aortic smooth muscle cells (ASMC). METHODS: PKC activity and cytosolic free Ca 2+ were measured by its ability to transfer phosphate from ATP to lysine-rich histone and flow cytometric analysis after loading with the Ca 2+ dye fluo 3/Am, respectively. RESULTS: OX-LDL increased PKC total activity in a dose-dependent manner and induced translocation of PKC from the cytosolic to membrane, while OX-LDL induced biphasic [Ca 2+ ]i responses including the rapid initial transient phase and the sustained phase. When simvastatin was added, the translocation of PKC was markedly decreased and simvastatin did not impair the initial peak response to OX-LDL but significantly reduced the subsequent plateau phase. CONCLUSSION: OX-LDL can induce dynamic changes of signal transduction of PKC and cytosolic free Ca 2+ in ASMC and these two events are closely linked.
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Objective: To investigate the effects of oxLDL and HMG CoA reductase inhibitor simvastatin on PKC activity, and level of cytosolic free Ca 2+ in cultured human umbilical vein endothelial cells. Methods: The activity of PKC was determined by its ability to transfer phosphate from 32 P ATP to lysine rich histone and level of cytosolic free calcium[Ca 2+ ]i was measured by flow cytometric analysis loading with the Ca 2+ dye Fluo 3/Am. Results: oxLDL increased PKC total activity in a dose dependent manner and peaked after 12 min, then decreased slowly and maintained for at least 30 min, while oxLDL induced biphasic [Ca 2+ ]i responses including the rapid initial transient phase and the sustained phase. Removal of extracellular Ca 2+ did not inhibit the rapid transient phase, but abolished the sustained phase. When simvastatin was added, the activity of PKC wasmarkedly decreased with no impairment to the initial peak response, but significantly reduced the sustained phase. Conclusion: oxLDL can induced dynamic changes of signal transduction of PKC and level of cytosolic free Ca 2+ in HUVEC, these 2 events are closely linked. The change of rapid initial transient phase is the result of mobilization of Ca 2+ from intracellular pool and the change of sustained phase is from the influx of extracellular Ca 2+ . The inhibition of PKC activity induced by simvastatin may contribute to the changes of [Ca 2+ ]i. [
