Complete genomic sequences, a key residue in the spike protein and deletions in nonstructural protein 3b of US strains of the virulent and attenuated coronaviruses, transmissible gastroenteritis virus and porcine respiratory coronavirus

Transmissible gastroenteritis virus (TGEV) isolates that have been adapted to passage in cell culture maintain their infectivity in vitro but may lose their pathogenicity in vivo. To better understand the genomic mechanisms for viral attenuation, we sequenced the complete genomes of two virulent TGEV strains and their attenuated counterparts: virulent TGEV Miller M6 and attenuated TGEV Miller M60 and virulent TGEV Purdue and attenuated TGEV Purdue P115, together with the ISU-1 strain of porcine respiratory coronavirus (PRCV-ISU-1), a naturally occurring TGEV deletion mutant with an altered respiratory tropism and reduced virulence. Pairwise comparison at both the nucleotide (nt) and amino acid (aa) levels between virulent and attenuated TGEV strains identified a common change in nt 1753 of the spike gene, resulting in a serine to alanine mutation at aa position 585 of the spike proteins of the attenuated TGEV strains. Alanine was also present in this protein in PRCV-ISU-1. Particularly noteworthy, the serine to alanine mutation resides in the region of the major antigenic site A/B (aa 506-706) that elicits neutralizing antibodies and within the domain mediating the cell surface receptor aminopeptidase N binding (aa 522-744). Comparison of the predicted polypeptide products of ORF3b showed significant deletions in the naturally attenuated PRCV-ISU-1 and TGEV Miller M60; these deletions occurred at a common break point, suggesting a related mechanism of recombination that may affect viral virulence or tropism. Sequence comparisons at both genomic and protein levels indicated that PRCV-ISU-1 had a closer relationship with TGEV Miller strains than Purdue strains. Phylogenetic analyses showed that virulence is an evolutionarily labile trait in TGEV and that TGEV strains as a group share a common ancestor with PRCV.     

Rapid optimized flow cytometric crossmatch (FCXM) assays: The Halifax and Halifaster protocols

The flow cytometric crossmatch (FCXM) assay, which detects the presence of donor specific HLA antibodies in patient sera, is a cornerstone of HLA compatibility testing. Since relatively long FCXM assay turnaround times may contribute to transplant delays and increased graft ischemia time, we developed and validated two modified crossmatch procedures, namely the Halifax and Halifaster FCXM protocols. These protocols reduce FCXM assay time?>60% and simplify their set-up without compromising quality or sensitivity. Optimization of the FCXM (the Halifax protocol) includes a 96-well tray platform, reduced wash times, increased serum to cell suspension volume ratio, shortened incubations and higher incubation temperature. The Halifaster protocol is a further modification, employing methods that improve lymphocyte purity compared to density gradient centrifugation (96?±?2.63% vs 69?±?19.06%), reduce cell isolation time (by?～40%) and conserve FCXM assay reagents. Importantly, linear regression analysis of the median channel fluorescence shift (MCFS) values revealed excellent concordance (R² of 0.98–0.99) among all three FCXM protocols (standard vs Halifax vs Halifaster). Finally, a retrospective review of 2013 crossmatches performed using the Halifax protocol demonstrated excellent correlation with the virtual crossmatch (95.7% and 96.8% specificity and sensitivity, respectively) regarding the identification of donor specific antibodies (HLA-A/B/DR) assigned based on the single antigen bead (SAB) assay testing with a 2000 mean fluorescence intensity (MFI) cutoff. Implementation of the Halifax or Halifaster protocols will expedite pre-transplantation work-up and improve patient care.     

磁共振水-脂分离成像对使用糖皮质激素类风湿患者骨量评价的研究

目的通过利用磁共振水-脂分离成像技术对使用糖皮质激素的类风湿患者椎体脂肪含量的测定,来评估不同年龄段类风湿患者随着激素应用时间的延长,椎体脂肪含量的变化,从而间接评估椎体骨质量。方法纳入40例类风湿患者为研究对象,按年龄分为30~40岁组20例、40~50岁组20例,不同年龄组在治疗前DXA行骨密度值(BMD值)与MR所测腰椎脂肪分数(FF)进行相关性分析;并对不同年龄组治疗前、激素治疗3个月后及6个月后腰椎椎体脂肪分数进行比较;骨髓脂肪FF计算公式:FF=[Mfat/(Mfat+Mwater)]*100%,式中Mwater、Mfat分别指水像及脂像ROI总像素信号强度值。结果不同年龄组类风湿患者治疗前BMD均值组间比较差异有统计学意义(P=0.007);所有患者椎体BMD值与FF值呈显著相关性;用药3个月后脂肪分数上升的程度明显高于用药6个月组,且40~50岁年龄组脂肪分数增加的程度要高于30~40岁年龄组。结论长期使用激素治疗的类风湿患者椎体内脂肪分数明显增加;发病年龄较大及用药时间长的患者腰椎脂肪分数呈逐渐上升趋势,提示使用激素治疗的类风湿患者椎体脂肪含量增加,椎体骨量下降,易发生骨质疏松性骨折。     

Third ventricle midline shift due to spontaneous supratentorial intracerebral hemorrhage evaluated by transcranial color-coded sonography.

OBJECTIVE: We aimed to assess the clinical usefulness of the third ventricle midline shift (MLS) evaluated by transcranial color-coded sonography (TCCS) in acute spontaneous supratentorial intracerebral hemorrhage (ICH). METHODS: Consecutive patients with acute (<24 hours after symptom onset) ICH were recruited for this TCCS study. Sonographic measurement of MLS and the pulsatility index (PI) of the middle cerebral arteries were compared with head computed tomographic (CT) data, including MLS, and hematoma volume. Poor functional outcome at 30 days after stroke onset was defined as modified Rankin scale greater than 2. RESULTS: There were 51 patients with spontaneous supratentorial ICH who received CT and TCCS studies within a 12-hour window. Correlation between MLS by TCCS (mean +/- SD, 3.2 +/- 2.6 mm) and CT (3.0 +/- 2.4 mm) was high (gamma = 0.91; P < .01). There was also a good linear correlation between hematoma volume and MLS by TCCS (gamma = 0.81; P < .01). Compared with ICH volume less than 25 mL, those with greater volume had more severe MLS and a higher PI of the ipsilateral middle cerebral artery (P < .001). Midline shift by TCCS was more sensitive and specific than the PI in detecting large ICH (accuracy = 0.82 if MLS > or = 2.5 mm), and it was also a significant predictor of poor outcome (odds ratio, 2.09 by 1-mm increase; 95% confidence interval, 1.06-4.13). CONCLUSIONS: Midline shift may be measured reliably by TCCS in spontaneous supratentorial ICH. Our study also showed that MLS on TCCS is a useful and convenient method to identify patients with large ICH and hematoma expansion and to predict short-term functional outcome.     

多导睡眠监测的护理观察

阻塞性睡眠呼吸暂停低通气综合症（OSAHS）是以反复发作的呼吸暂停，严重打鼾，白天嗜睡为特征的一种疾病。由于睡眠时上气道塌陷从而导致呼吸暂停、低氧血症和睡眠中多次唤醒。长期存在可引起重要器官的慢性损害，是一种潜在危害健康的疾病。通过对本科136例患儿OSAHS监测，探讨如何加强护理观察，提高监测的成功率和准确性，现报告如下。     

In situ force in the anterior cruciate ligament,the lateral collateral ligament,and the anterolateral capsule complex during a simulated pivot shift test

The role of the anterolateral capsule complex in knee rotatory stability remains controversial. Therefore, the objective of this study was to determine the in situ forces in the anterior cruciate ligament (ACL), the anterolateral capsule, the lateral collateral ligament (LCL), and the forces transmitted between each region of the anterolateral capsule in response to a simulated pivot shift test. A robotic testing system applied a simulated pivot shift test continuously from full extension to 90° of flexion to intact cadaveric knees (n = 7). To determine the magnitude of the in situ forces, kinematics of the intact knee were replayed in position control mode after the following procedures were performed: (i) ACL transection; (ii) capsule separation; (iii) anterolateral capsule transection; and (iii) LCL transection. A repeated measures ANOVA was performed to compare in situ forces between each knee state (*p < 0.05). The in situ force in the ACL was significantly greater than the forces transmitted between each region of the anterolateral capsule at 5° and 15° of flexion but significantly lower at 60°, 75°, and 90° of flexion. This study demonstrated that the ACL is the primary rotatory stabilizer at low flexion angles during a simulated pivot shift test in the intact knee, but the anterolateral capsule plays an important secondary role at flexion angles greater than 60°. Furthermore, the contribution of the “anterolateral ligament” to rotatory knee stability in this study was negligible during a simulated pivot shift test. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:847–853, 2018.

     

护士夜班排班方式对增加直接护理时数及护理质量的影响

目的探索增加直接护理时数及提高护理质量的护士夜班排班方式。方法根据病房工作量的分类方法,对临床内外科护士三班倒换制、全夜制夜班的间接、直接护理时数统计,比较不同夜班排班方式对直接护理时数及护理质量的影响。结果全夜制夜班对比倒换制夜班护士每24h可增加直接护理时数66min,折算为1.06h,P<0.001;全夜制夜班夜间护理病人综合满意度为95.67%;病区夜间护理质量达标率100%。结论全夜制夜班可减少护士频繁交接班而增加直接护理时数,有利于提高护理效率及护理质量。     

护理排班模式改革探讨

目的　探讨高效、全程优质服务的护理排班模式。方法　在原有人力基础上 ,改变人力结构 ,实施全夜制 (9PM～ 9AM ) ,2 4h分 3个班次 ,并增设护理骨干值二线班。结果　与传统式比较 ,护士交班、书写次数明显减少 ,抢救病人成功率从 2 5 %提高到 67% ,病人满意度从 94.5 %提高到 10 0 % (P <0 .0 5 )。结论　护理排班模式改革后 ,加强了中午、晚上的薄弱环节 ,为抢救赢得了时间 ,护士业务方面又起到互补互相促进作用     

Cross-spectral analysis of heart rate and blood pressure modulations

The cross-spectral analysis of heart rate (HR) and blood pressure (BP) variabilities provides "amplitude" and "phase" related measures. Compared to the amplitude measure, that is the baroreflex gain, the phase related measure characterizing the time lag between HR and BP oscillations has been studied to a much lesser extent. A population of 103 patients (73 men, 30 women, aged 53 +/- 12, range 20-82 years) referred for the management of coronary artery disease and/or hypertension were studied. In each subject, electrocardiogram and BP recordings were obtained in the supine and sitting positions of 5 minutes of rest (spontaneous respiration), 3 minutes of controlled respiration at 0.1 Hz (slow-controlled respiration), and 3 minutes of controlled respiration at 0.33 Hz (fast-controlled respiration). The frequency of maximum coherence (above the arbitrary threshold of 0.5) of BP and RR interval variabilities was searched between 0.033-0.133 Hz and 0.200-0.400 Hz to obtain baroreflex gain and phase shift in low and high frequency bands, respectively. Mean phase shifts of -79.1 and -67.0 degrees (-2.4 and -2.1 s) were found during slow-controlled respiration in the supine and sitting body positions, respectively. The mean phase shift between systolic BP and RR interval in the low frequency band was found between 83 and -109 degrees for body positions and respiration regimes. The actual baroreflex related time lag between systolic BP and RR variations was found between 3.5 and 5.1 seconds. The study concludes that the appropriate, and not always easy, selection of the frequency of maximum coherence between BP and HR oscillation is crucial for an accurate cross-spectral assessment of baroreflex sensitivity.