Assembly of influenza ribonucleoprotein in vitro using recombinant nucleoprotein

The influenza A virus nucleoprotein previously expressed in Escherichia coli after fusion to 32 heterologous amino acids has now been purified and tested for its ability to form complexes with RNA in vitro. By using a simple filter binding assay, we show that ribonucleoprotein (RNP) complexes form readily with single-stranded RNA of viral or nonviral origin but not with double-stranded RNA. The RNP complexes formed were similar to authentic influenza virus RNPs in appearance under the electron microscope, in buoyant density in gradients of cesium chloride, and in sensitivities to pancreatic ribonuclease, to chaotropic reagents, and to high salt. We conclude that nucleoprotein synthesized in E. coli has all the properties required for correct assembly into ribonucleoprotein.     

针灸镇痛应用于急性牙髓炎一次性根管术治疗临床研究

目的:探讨针灸镇痛应用于急性牙髓炎一次性根管术镇痛中的临床疗效.方法:将120例急性牙髓炎患者按随机数字表法分为对照组和研究组各60例.对照组给予常规阿替卡因和利多卡因局部阻滞麻醉治疗,研究组在对照组基础上给予针灸镇痛治疗.比较2组临床疗效及不良反应发生情况.结果:研究组总有效率为98.33％,高于对照组85.00％,...     

Regional differences in the severity of Lewy body pathology across the olfactory cortex

We studied α-synuclein pathology in the rhinencephalon of ten cases of Parkinson's disease (PD) and twelve neurologically normal controls, of which seven had incidental Lewy bodies in the substantia nigra at autopsy and five had no pathological evidence of neurological disease. In all PD and incidental Lewy bodies cases, α-synuclein pathology was found in all five subregions of the primary olfactory cortex that were sampled, and amongst them the pathology was significantly more severe in the temporal division of the piriform cortex than in the frontal division of the piriform cortex, olfactory tubercle or anterior portions of the entorhinal cortex. The orbitofrontal cortex, which is an area of projection from the primary olfactory cortex, was affected in some cases but overall the α-synuclein pathology was less severe in this area than in the primary olfactory cortex. Because different areas of the rhinencephalon are likely to play different roles in olfaction and our data indicate a differential involvement by α-synuclein deposition of structures implicated in smell, future prospective studies investigating the pathophysiological basis of hyposmia in PD should consider to examine the areas of primary olfactory cortex separately.     

Multicenter evaluation of the Panbio™ COVID-19 rapid antigen-detection test for the diagnosis of SARS-CoV-2 infection

ObjectivesThe standard RT-PCR assay for coronavirus disease 2019 (COVID-19) is laborious and time-consuming, limiting testing availability. Rapid antigen-detection tests are faster and less expensive; however, the reliability of these tests must be validated before they can be used widely. The objective of this study was to determine the performance of the Panbio? COVID-19 Ag Rapid Test Device (PanbioRT) (Abbott) in detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nasopharyngeal swab specimens.MethodsThis prospective multicentre study was carried out in ten Spanish university hospitals and included individuals with clinical symptoms or epidemiological criteria of COVID-19. Only individuals with ≤7 days from the onset of symptoms or from exposure to a confirmed case of COVID-19 were included. Two nasopharyngeal samples were taken to perform the PanbioRT as a point-of-care test and a diagnostic RT-PCR test.ResultsAmong the 958 patients studied, 325 (90.5%) had true-positive results. The overall sensitivity and specificity for the PanbioRT were 90.5% (95%CI 87.5–93.6) and 98.8% (95%CI 98–99.7), respectively. Sensitivity in participants who had a threshold cycle (C_T) < 25 for the RT-PCR test was 99.5% (95%CI 98.4–100), and in participants with ≤5 days of the clinical course it was 91.8% (95%CI 88.8–94.8). Agreement between techniques was 95.7% (κ score 0.90; 95%CI 0.88–0.93).ConclusionsThe PanbioRT performs well clinically, with even more reliable results for patients with a shorter clinical course of the disease or a higher viral load. The results must be interpreted based on the local epidemiological context.     

INK4a/ARF mutations accelerate lymphomagenesis and promote chemoresistance by disabling p53

The INK4a/ARF locus encodes upstream regulators of the retinoblastoma and p53 tumor suppressor gene products. To compare the impact of these loci on tumor development and treatment response, the Emu-myc transgenic lymphoma model was used to generate genetically defined tumors with mutations in the INK4a/ARF, Rb, or p53 genes. Like p53 null lymphomas, INK4a/ARF null lymphomas formed rapidly, were highly invasive, displayed apoptotic defects, and were markedly resistant to chemotherapy in vitro and in vivo. Furthermore, INK4a/ARF(-/-) lymphomas displayed reduced p53 activity despite the presence of wild-type p53 genes. Consequently, INK4a/ARF and p53 mutations lead to aggressive tumors by disrupting overlapping tumor suppressor functions. These data have important implications for understanding the clinical behavior of human tumors.     

Synthesis and thermodynamic studies of two new polymers carrying amido and amino groups in the side chains

Two linear vinyl polymers carrying amido and primary amino groups in the side chains were synthesized and characterized. Their behaviour in aqueous solution was investigated by potentiometric, viscometric and calorimetric techniques. In both cases, the basicity constants show a linear dependence on the degree of protonation α, while the enthalpy values of protonation do not. The thermodynamic results demonstrate the important role of hydrophobic interactions on the protonation process.     

In vitro blood-brain barrier permeability and cerebral endothelial cell uptake of the neuroprotective nitrone compound NXY-059 in normoxic,hypoxic and ischemic conditions

The free radical trapping nitrone compounds alpha-phenyl-N-tert-butylnitrone (PBN), 2-sulfophenyl-N-tert-butylnitrone (S-PBN) and disodium 2,4-disulfophenyl-N-tert-butyl nitrone (NXY-059) are effective neuroprotective agents in experimental models of both transient and permanent focal ischemia. A recent in vivo study suggested that NXY-059 had poor brain uptake in a transient ischemia model. We have now examined its blood-brain barrier permeability and cerebral endothelial uptake during hypoxic and ischemic conditions using an in vitro model of the blood-brain barrier. The in vitro blood-brain barrier permeability and cerebral endothelial uptake of NXY-059 and S-PBN were low during normoxic conditions. In contrast, PBN had very high blood-brain barrier penetration in vitro which confirmed earlier in vivo results. The permeability of [14C]NXY-059 increased 3.5 times after 9 h of hypoxia or 3 h of ischemia. There was, respectively, a 5-fold and more than 10-fold increase, after 6 and 9 h of ischemia. The control molecule [3H]inulin (M(r) approximately 5000) showed a similar increase in permeability under the same experimental conditions indicating a major change in the transport properties of the endothelium. There was a 60% reduction in the ATP levels of astrocytes after 3 h of ischemia and a 90% reduction after 9 h. The reduction in ATP levels in endothelial cells was somewhat lower. The uptake of NXY-059 in cerebral endothelial cells under normoxic, hypoxic or 9 h of ischemic conditions was negligible. NXY-059, S-PBN and PBN showed no effects on vesicular transport or the integrity of the blood-brain barrier in normoxic or ischemic conditions, nor did the compounds induce any change in the ATP levels of the cells. In conclusion, it is possible that the increase in blood-brain barrier permeability of [14C]NXY-059 which occurs during prolonged ischemia in vitro reflects a change which may be of importance to the neuroprotective effects of this nitrone free radical trapping agent.