The origin of a novel kind of reassortant (H1N2) of influenza A virus

Genetic analysis of three H1N2 viruses indicated that only HA genes of H1N2 viruses were similar to that of A/Guangdong/6/91(H1N1) virus (PR8-like strain), while the other seven genes of them were similar to those of H3N2 virus circulating in man in 1995. Therefore, it could be considered that the H1N2 viruses were derived from reassortment between PR8-like strain and H3N2 virus circulating in man in 1995. However, the genomes of H1N2 viruses were very similar to each other. So the H1N2 viruses isolated in 1998 were not derived from new reassortment between PR8-like strain and H3N2 virus circulating in man in 1998, but derived from the evolution of H1N2 virus found in 1995.     

High Selenium Yeast mitigates aluminum-induced cerebral inflammation by increasing oxidative stress and blocking NO production

High Selenium Yeast (SeY) serves many important roles with respect to the maintenance of normal nervous system functioning. Studies have reported the nerve inflammation induced by Aluminum (Al) was associated with the increase of mortality. However, in-depth studies are required to verify the hypothesized neuro-protective efficacy of SeY against Al-induced cerebral damage through modulation of the inflammatory response. Here, mice were treated with SeY (0.1 mg/kg) and/or Al (10 mg/kg) by oral gavage for 28 days. Inflammation was assessed by histopathological examination and expression of biomarkers for inflammation. Furthermore, the oxidation–reduction levels and the NO production were assessed using diagnostic kits and RT-PCR. The data indicated that SeY significantly protected cerebrum against Al-induced pathological changes, in addition to the disordered expression of biomarkers of inflammation, the imbalance of oxidation–reduction, and the increase of NO production. Therefore, the chemoprotective potential of SeY against Al-induced cerebral inflammation via restore the levels of oxidation–reduction and the generation of NO was demonstrated.     

Effects of Excitatory Amino Acids on Cerebral Oxygen Consumption and Blood Flow in Rat

This investigation tested the importance of excitatory amino acids' effects on regional cerebral O₂ consumption and the concomitant changes in cerebral blood flow (rCBF) in isoflurane anesthetized rats. In the glutamate or N-methyl-D-aspartate (NMDA) groups, 10^–2 M glutamate or NMDA was topically applied to the right cortex and the left cortex was used as a control. One mg/kg dizocilpine maleate (MK-801), a non-competitive NMDA receptor antagonist, was administered (iv) to the MK-801 group and saline was given to the control group. Cortical rCBF was determined using ¹⁴C-iodoantipyrine and regional O₂ extraction was measured microspectrophotometrically. Cerebral O₂ consumption increased 77% after glutamate (contralateral cortex: 9.0 ± 1.1 ml O₂/min/100 g, glutamate treated cortex: 15.9 ± 3.9), while a 46% increase was observed with the same concentration of NMDA (contralateral cortex: 9.8 ± 2.0, NMDA treated cortex: 14.3 ± 5.5). After MK-801, the O₂ consumption decreased to 37% of the control value (control cortex: 7.0 ± 1.3, MK-801 treated cortex: 2.6 ± 3.9). MK-801 significantly decreased cerebral O₂ extraction from 7.1 ± 1.3 ml O₂/100 ml (control cortex) to 5.3 ± 0.6 (MK-801 treated cortex). However, there was no significant difference in cerebral O₂ extraction between treated and contralateral cortex in either the glutamate or NMDA groups. The increase in O₂ consumption caused by glutamate or NMDA was coupled with increased rCBF. Glutamate increased rCBF from 95 ± 5 ml/min/100 g (contralateral cortex) to 165 ± 31 (treated cortex), while NMDA increased rCBF from 114 ± 12 (contralateral cortex) to 178 ± 60 (treated cortex). MK-801 decreased O₂ consumption with a lesser decrease of rCBF. The rCBF was 48 ± 9 in the MK-801 treated cortex and 99 ± 22 in the control cortex. Some substances produced by the activation of NMDA receptors may be related to the coupling of cerebral metabolism and blood flow, since after blockade of NMDA receptors with MK-801, this relationship is uncoupled. These findings suggest that glutamatergic processes have a major effect on cerebral O₂ consumption and that this is at least partly due to NMDA receptors.     

Nitrogen and Sulfur Codoped Graphite Foam as a Self‐Supported Metal‐Free Electrocatalytic Electrode for Water Oxidation

The oxidation of water to produce oxygen gas is related to a variety of energy storage systems. Thus, the development of efficient, cheap, durable, and scalable electrocatalysts for oxygen evolution reaction (OER) is of great importance. Here, a high‐performance OER catalyst, nitrogen and sulfur codoped graphite foam (NSGF) is reported. This NSGF is prepared from commercial graphite foil and directly applied as an electrocatalytic electrode without using a current collector and a polymeric binder. It exhibits an extremely low overpotential of 0.380 V to reach a current density of 10 mA cm^?2 and shows fast kinetics with a small Tafel slope of 96 mV dec^?1 in 0.1 m KOH. This electrocatalytic performance is superior or comparable to those of previously reported metal‐free OER catalysts.     

不同脊椎动物消化道内5-羟色胺免疫染色细胞的分布

用过氧化物酶——抗过氧化物酶（PAP）法,对乌鳢（Ophiccephalus argus）、中华大蟾蜍（Bufo bufo garaaarizans）、黄喉水龟（Clemmys mutica）、虎皮鹦鹉（Melopsittacus undulatus）和小白鼠（Mus musculus albula）五种脊椎动物消化道内的5-羟色胺（5-hydroxytryptamine,简称5-HT）免疫染色细胞的分布进行了研究。发现各种动物胃肠道（虎皮鹦鹉胃、乌鳢肠及胃贲门除外）均含有5-HT免疫染色细胞,并首次发现黄喉水龟和中华大蟾蜍食道内含有5-HT免疫染色细胞。一般地,各种动物胃内5-HT免疫染色细胞密度最高,十二指肠和大肠次之,小肠最低。5-HT免疫染色细胞位于粘膜上皮或腺上皮细胞间,常有一个或一个以上的细胞突起伸入固有层或肠腔面（或腺腔面）,有些细胞的一端突起伸入固有层,另一端突起伸入肠腔面,表明5-HT免疫染色细胞兼具内分泌或分泌功能。     

Double-sides sticking mechanism of vinblastine interacting with α,β-tubulin to get activity against cancer cells

Abstract

Vinblastine (VLB) and its derivatives have been used for clinical first-line drugs to treat various cancers. Due to the resistance and serious side effects from using VLB and its derivatives, there is a need to discover and develop novel VLB derivatives with high activity against cancer cells. In order to better discover and develop new VLB derivatives, we need to study the structural basis of VLB's anti-cancer cytotoxicity and the mechanism of its interaction with α,β-tubulins. Based on the crystal structure of α,β-microtubule complex protein, the molecular dynamics method including the sampling PMF method was used to study the variation of dissociation free energy (ΔG) of α,β-tubulins under different system conditions, and then from which to study the mechanism of the interaction between VLB and α,β-tubulins. The obtained results show that the dissociation of pure α,β-tubulins requires 197.8?kJ·mol^?1 for ΔG. When the VLB molecule exists between the interface of α,β-tubulins, the dissociation ΔG of α,β-tubulins reaches 220.5?kJ·mol^?1, which is greater than that of pure α,β-tubulin. The VLB molecule is formed by connecting a vindoline moiety (VM) molecule with a catharanthine moiety (CM) molecule through a carbon-carbon bond, which is a larger molecule. When the CM molecule exists in the middle of α,β-tubulin interface, the dissociation ΔG of α,β-tubulins is 46.2?kJ·mol^?1, during which the CM moves with β-tubulin. When the VM molecule exists between the middle of α,β-tubulin interface, the dissociation ΔG of α,β-tubulins is 86.7?kJ·mol^?1, during which it moves with α-tubulin. Therefore, the VLB molecule is like a double-sides tape to stick α-tubulin and β-tubulin together. The VLB molecule intervenes the dynamic equilibrium between dissociation and aggregation of α-tubulin and β-tubulin by a double-sides sticking mechanism to exert high activity with toxicity against cancer cell. Besides, our results demonstrate that VLB has its structural basis for anticancer cytotoxicity due to its two compositions composed of a CM molecule and a VM molecule although they have little toxicity against cancer cell alone.