导航辅助射频温控热凝术中注册标记系统的改良

目的：改进导航辅助射频温控热凝术中的注册标记系统,使其更加无创,同时达到导航系统的精确要求。方法：采用热塑型塑料面罩,依照人体面部特征加热塑型,表面双侧颞部、眉弓中点和颧骨最高点安置6个塑料标记点．内部随意安置6个标记点。CT扫描获得影像学数据,输入SurgView—RFT电磁导航系统后,分别选用4个（内外各2个）、6个（内外各3个）和8个（内外各4个）标记点进行注册和配准,每组设置5种组合,每点读取3次坐标值,取平均值代入配准误差公式。采用SAS6．12软件包对数据进行t检验。结果：取4个标记点时．系统误差为f1．58_±0．25）mm;取6个标记点时,系统误差为（1．28±0．21）mm;当标记点数量达到8个时,导航系统的配准精度达（1．06±0．10）mm。4点组与6点组间有显著差异（P=0．0149）,6点组与8点组间无显著差异（P=0.1402）。结论：热塑型塑料面罩表面放置标记点可避免患者创伤,配准精度完全符合导航系统的要求和卯圆孔穿刺的特定要求,在应用中至少应有6个标记点。     

新型冠状病毒的变异株进展:起源、变异动力与防控措施

新型冠状病毒肺炎(COVID?19)自2019年12月出现后,迅速在全球流行,演变为全球重大公共卫生问题.新型冠状病毒(SARS?CoV?2)为单股正链核糖核酸(RNA)病毒,自然突变率较高;变异株的出现往往是"变异—选择—适应"的进化产物.此外,炎症状态下激活的APOBEC酶可促进病毒变异.目前发现有公共卫生意义的S...     

转豇豆胰蛋白酶抑制剂大米的致畸作用研究

目的　用表达杀虫蛋白CpTI(豇豆胰蛋白酶抑制剂 )的大米喂养Wistar大鼠 ,研究其是否具有致畸作用。方法　将断乳的Wistar大鼠随机分为 4组 ,转基因大米组、非转基因大米组、阴性对照组和阳性对照组 ,敌枯双为阳性对照物。转基因大米组含 78 3%转基因大米 ,非转基因大米组含 74 7%与转基因大米同品系的非转基因大米 ,两个对照组的饲料为AIN93G ,三种饲料的宏量及微量营养素的含量相同。大鼠性成熟后 ,进行传统的致畸实验 ,观察母鼠及胎鼠的情况。结果　转基因大米组的孕鼠增重、胎鼠体重、身长和尾长显著高阳性对照组 ,畸形率 (包括外观畸形、骨骼畸形和内脏畸形 )显著低于阳性对照组 (P <0 0 1) ,转基因大米组、非转基因大米组及阴性对照组间的所有指标均无显著性差异 (P >0 0 5 )。结论　此种转CpTI基因的大米对大鼠无母体毒性、胚胎毒性和致畸作用。     

Guidelines and selection criteria for secondary cytoreductive surgery in patients with recurrent, platinum-sensitive epithelial ovarian carcinoma

BACKGROUND: The benefit of cytoreductive surgery for patients with recurrent epithelial ovarian cancer has not been defined clearly. The objective of this study was to identify prognostic factors for survival in patients who underwent secondary cytoreduction for recurrent, platinum-sensitive epithelial ovarian cancer and to establish generally applicable guidelines and selection criteria. METHODS: The authors reviewed all patients who underwent secondary cytoreduction for recurrent epithelial ovarian cancer from 1987 to 2001. Potential prognostic factors were evaluated in univariate and multivariate analyses. RESULTS: In total, 157 patients underwent secondary cytoreduction, and 153 of those patients were evaluable. After secondary cytoreduction, the median follow-up was 36.9 months (range, 0.2-125.6 months), and the median survival was 41.7 months (95% confidence interval, 36.0-47.2 months). For patients who had a disease-free interval prior to recurrence of between 6 months and 12 months, the median survival was 30 months compared with 39 months for patients who had a disease-free interval between 13 months and 30 months and 51 months for patients who had a disease-free interval >30 months (P = .005). For patients who had a single site of recurrence, the median survival was 60 months compared with 42 months for patients who had multiple sites of recurrence and 28 months for patients who had carcinomatosis (P <.001). The median survival for patients who had residual disease that measured < or =0.5 cm was 56 months compared with 27 months for patients who had residual disease that measured >0.5 cm (P <.001). On multivariate analysis, disease-free interval (P = .004), the number of recurrence sites (P = .01), and residual disease (P <.001) were significant prognostic factors. CONCLUSIONS: In the authors' analysis of secondary cytoreduction for recurrent epithelial ovarian cancer, a significant survival benefit was demonstrated for residual disease that measured < or = 0.5 cm. The disease-free interval and the number of recurrence sites should be used as selection criteria for offering secondary cytoreduction.     

半椎板切除技术与套筒技术在椎管内肿瘤手术中的应用

目的 探讨半椎板切除技术与套筒技术在椎管内肿瘤切除术中的应用效果.方法 回顾性分析2018～2020年显微手术治疗的14例椎管内肿瘤的临床资料,采用半椎板切除技术12例,套筒技术2例.结果 14例肿瘤均获全切除.术后随访4～20个月,症状均改善,影像学检查肿瘤均无复发,无脊柱畸形.结论 半椎板切除技术与套筒技术在椎管内...     

人工肱骨头置换中使用胸骨针行肱骨近端骨折肩袖重建

背景：越来越多的粉碎、移位严重而无法重建的肱骨近端骨折患者需要行人工肱骨头置换,但此类患者肩袖的重建直接影响治疗效果,置换过程中往往需要良好的肩袖重建。 目的：探讨胸骨针在肱骨近端骨折人工肱骨头置换肩袖重建中的应用体会。 方法：34例肱骨近端四部分骨折患者行人工肱骨头置换时使用胸骨针修复肩袖,年龄67-78岁。人工肱骨头置换时未过分剥离骨折块与肩袖组织,保留肩袖组织与骨块相连,将胸骨针沿着肩袖大小结节表面肌腱-骨结合部环形缝合备用,可用多根,假体置入后,将肱骨大、小结节及碎骨块解剖复位,收紧胸骨针,大小结节及肩袖附着的碎骨块均原位贴在人工肱骨头下方。术中应尽可能将残余的肩袖和肌肉组织损伤进行缝合修复,并要注意缝合后的动力平衡。采用Neer标准对人工肩关节功能的恢复情况进行评价。 结果与结论：34例患者均获随访,随访时间1-3年,24例优,10例良,2例可;无关节脱位、半脱位等关节不稳情况,未见感染、神经损伤及假体松动病例。提示人工肱骨头置换过程中使用胸骨针进行肩袖修复及大小结节固定能使肩袖和大小结节接近解剖位置,并且比常规的涤纶线强度高,固定牢靠,能满足人工肱骨头置换后康复训练的需要,对肩关节的稳定性及功能恢复有重要作用。     

基层中医药服务能力提升工程下患者对社区中医师信任度评价分析

目的评价基层中医药服务能力提升工程下,患者对社区中医师的信任度及中医预防保健服务对其的影响。方法于2017年9月,用维克森林医师信任量表(WFPTS)中文版测量浙江省三地22家社区卫生服务中心的1391例患者对社区中医师的信任度。定量变量描述采用均数和标准差,定性变量描述采用构成比。采用t检验、方差分析、Kruskal-Wallis检验比较差异。结果WFPTS中文版用于社区中医师的信效度良好。患者对社区中医师信任度的总均分为(38.00±6.42)分,仁爱、技能维度分别为(19.14±3.41)分、(18.82±3.50)分;信任度在患者人口学特征和对社区中医预防保健服务知晓的数量、途径和利用上,差异有统计学意义;患者的性别、年龄、对社区中医预防保健服务的知晓率和利用等因素,影响社区中医师的信任度。结论患者对社区中医师的信任度较高。提高社区中医预防保健服务的知晓率和利用率,有利于提升患者对社区中医师的信任度。建议加强宣教,多渠道提升社区中医师的技能水平。     

Novel druggable hot spots in avian influenza neuraminidase H5N1 revealed by computational solvent mapping of a reduced and representative receptor ensemble

The influenza virus subtype H5N1 has raised concerns of a possible human pandemic threat because of its high virulence and mutation rate. Although several approved anti-influenza drugs effectively target the neuraminidase, some strains have already acquired resistance to the currently available anti-influenza drugs. In this study, we present the synergistic application of extended explicit solvent molecular dynamics (MD) and computational solvent mapping (CS-Map) to identify putative 'hot spots' within flexible binding regions of N1 neuraminidase. Using representative conformations of the N1 binding region extracted from a clustering analysis of four concatenated 40-ns MD simulations, CS-Map was utilized to assess the ability of small, solvent-sized molecules to bind within close proximity to the sialic acid binding region. Mapping analyses of the dominant MD conformations reveal the presence of additional hot spot regions in the 150- and 430-loop regions. Our hot spot analysis provides further support for the feasibility of developing high-affinity inhibitors capable of binding these regions, which appear to be unique to the N1 strain.     

INAUGURAL ARTICLE by a Recently Elected Academy Member:Functional redundancy of type I and type II receptors in the regulation of skeletal muscle growth by myostatin and activin A

Myostatin (MSTN) is a transforming growth factor-β (TGF-β) family member that normally acts to limit muscle growth. The function of MSTN is partially redundant with that of another TGF-β family member, activin A. MSTN and activin A are capable of signaling through a complex of type II and type I receptors. Here, we investigated the roles of two type II receptors (ACVR2 and ACVR2B) and two type I receptors (ALK4 and ALK5) in the regulation of muscle mass by these ligands by genetically targeting these receptors either alone or in combination specifically in myofibers in mice. We show that targeting signaling in myofibers is sufficient to cause significant increases in muscle mass, showing that myofibers are the direct target for signaling by these ligands in the regulation of muscle growth. Moreover, we show that there is functional redundancy between the two type II receptors as well as between the two type I receptors and that all four type II/type I receptor combinations are utilized in vivo. Targeting signaling specifically in myofibers also led to reductions in overall body fat content and improved glucose metabolism in mice fed either regular chow or a high-fat diet, demonstrating that these metabolic effects are the result of enhanced muscling. We observed no effect, however, on either bone density or muscle regeneration in mice in which signaling was targeted in myofibers. The latter finding implies that MSTN likely signals to other cells, such as satellite cells, in addition to myofibers to regulate muscle homeostasis.

Myostatin (MSTN) is a secreted signaling molecule that normally acts to limit skeletal muscle growth (for review, see ref. 1). Mice lacking MSTN exhibit dramatic increases in muscle mass throughout the body, with individual muscles growing to about twice the normal size (2). MSTN appears to play two distinct roles in regulating muscle size, one to regulate the number of muscle fibers that are formed during development and a second to regulate the growth of those fibers postnatally. The sequence of MSTN has been highly conserved through evolution, with the mature MSTN peptide being identical in species as divergent as humans and turkeys (3). The function of MSTN has also been conserved, and targeted or naturally occurring mutations in MSTN have been shown to cause increased muscling in numerous species, including cattle (3–5), sheep (6), dogs (7), rabbits (8), rats (9), swine (10), goats (11), and humans (12). Numerous pharmaceutical and biotechnology companies have developed biologic agents capable of blocking MSTN activity, and these have been tested in clinical trials for a wide range of indications, including Duchenne and facioscapulohumeral muscular dystrophy, inclusion body myositis, muscle atrophy following falls and hip fracture surgery, age-related sarcopenia, Charcot–Marie–Tooth disease, and cachexia due to chronic obstructive pulmonary disease, end-stage kidney disease, and cancer.The finding that certain inhibitors of MSTN signaling can increase muscle mass even in Mstn^−/− mice revealed that the function of MSTN as a negative regulator of muscle mass is partially redundant with at least one other TGF-β family member (13, 14), and subsequent studies have identified activin A as one of these cooperating ligands (15, 16). MSTN and activin A share many key regulatory and signaling components. For example, the activities of both MSTN and activin A can be modulated extracellularly by naturally occurring inhibitory binding proteins, including follistatin (17, 18) and the follistatin-related protein, FSTL-3 or FLRG (19, 20). Moreover, MSTN and activin A also appear to share receptor components. Based on in vitro studies, MSTN is capable of binding initially to the activin type II receptors, ACVR2 and ACVR2B (also called ActRIIA and ActRIIB) (18) followed by engagement of the type I receptors, ALK4 and ALK5 (21). In previous studies, we presented genetic evidence supporting a role for both ACVR2 and ACVR2B in mediating MSTN signaling and regulating muscle mass in vivo. Specifically, we showed that mice expressing a truncated, dominant-negative form of ACVR2B in skeletal muscle (18) or carrying deletion mutations in Acvr2 and/or Acvr2b (13) have significantly increased muscle mass. One limitation of the latter study, however, was that we could not examine the consequence of complete loss of both receptors using the deletion alleles, as double homozygous mutants die early during embryogenesis (22). Moreover, the roles that the two type I receptors, ALK4 and ALK5, play in regulating MSTN and activin A signaling in muscle in vivo have not yet been documented using genetic approaches. Here, we present the results of studies in which we used floxed alleles for each of the type II and type I receptor genes in order to target these receptors alone and in combination in muscle fibers. We show that these receptors are functionally redundant and that signaling through each of these receptors contributes to the overall control of muscle mass.     

Reproducibility of MR perfusion and 1H spectroscopy of bone marrow

Purpose

To determine the reproducibility of proton (¹H) magnetic resonance (MR) spectroscopy and dynamic contrast‐enhanced MR imaging in a clinical setting for the assessment of marrow fat fraction and marrow perfusion in longitudinal studies.

Materials and Methods

In all, 36 subjects (17 females, 19 males, mean age 72.9 ± 2.9 years) who underwent MR spectroscopy and/or dynamic contrast‐enhanced perfusion imaging of the proximal femur were asked to return after 1 week for a repeat MR examination.

Results

Reproducibility of ¹H MR spectroscopy in all bone areas tested was high, ranging from 0.78–0.85, with the highest reproducibility being in the femoral head and lowest in the femoral neck. Reproducibility of paired perfusion measurements ranged from 0.59 (enhancement slope femoral head) to 0.98 (enhancement maximum acetabulum). Overall reproducibility of ¹H MR spectroscopy and dynamic contrast‐enhanced imaging tended to be best in areas with the highest inherent fat fraction or perfusion.

Conclusion

Reproducibility of ¹H MR spectroscopy or perfusion imaging is sufficiently high to warrant these techniques being applied to the longitudinal study of bone diseases. J. Magn. Reson. Imaging 2009;29:1438–1442. © 2009 Wiley‐Liss, Inc.