羟基磷灰石与骨界面抗张强度测试及扫描电镜观察

本文测试了孔隙率为１４％，孔径小于２μｍ的纯羟基磷灰石（ＨＡ）与兔胫骨皮质骨之间界面的抗张强度，２周时为０．７２ＭＰａ；４、８、１６周之间强度无明显差异平均为１．５ＭＰａ。扫描电镜观察表明，２周时拉伸断裂位于ＨＡ－骨界面，４周以后多在ＨＡ晶体颗粒之间。ＨＡ与骨生物适应性好，矿化组织可以直接沉着于ＨＡ表面或ＨＡ内部，近界面处的ＨＡ发生了一定的生物降解反应，且骨矿化与ＨＡ的降解可能达到某种平衡。     

负压封闭吸引对糖尿病溃疡愈合的促进作用

目的 在"创而床准备(WBP)"理论指导下,观察负压封闭吸引局部处理糖尿病溃疡的疗效.方法 收集2000年1月至2005年1月间收治的27例糖尿病溃疡患者作对照组,2005年1月至2007年6月的8例糖尿病溃疡患者为试验组.两组患者均经常规系统的治疗,试验组在创面的黑、黄期采用清创后负压吸引治疗.观察两组创而各分期间的演进情况.比较两组手术Ⅰ期修复率、入院首次及实施负压治疗后1、2、3周创面细菌学检查结果 .观察各期创面组织标本的HE染色和黄、红两期Ⅰ、Ⅲ型胶原纤维苦味酸-天狼猩红染色结果 及对其含量进行图像分析.结果 试验组患者创面各分期的演进速度、于术Ⅰ期修复率均优于以照组(100%比46%,P<0.05).治疗2周后试验组创面末检出致病菌,对照组检出率为66.7%(P<0.05).HE染色显示试验组各期间的演进类似于急性创面愈合过程,且试验组黄期Ⅰ、m型胶原总含量为12.28%,对照组为24.77%(P<0.01).结论 基于WBP方案的负压吸引治疗能促进糖尿病溃疡的创面愈合过程.     

1049例育龄妇女下生殖道感染情况调查

目的了解育龄妇女下生殖道感染情况,为育龄女性生殖健康提供进一步的数据资料。方法对1049例来自健康体检中心的21~40岁育龄妇女的阴道后穹窿及宫颈分泌物标本进行检测,阴道清洁度、滴虫采用显微镜镜检法,淋球菌、解脲支原体、人型支原体、真菌采用培养法,沙眼衣原体则采用免疫层析法。检测结果进行统计学分析。结果女性生殖道感染的感染率为53.3%,其中混合感染率为9.8%,而清洁度异常率仅为28.4%;前三位病原体感染依次为解脲支原体(35.9%)、衣原体(18.1%)、真菌(6.7%)。结论女性生殖道感染情况严重,具有隐匿性,应加强对无症状感染的育龄妇女的监测。     

Antibody dynamics to SARS-CoV-2 in asymptomatic COVID-19 infections

Background

The missing asymptomatic COVID-19 infections have been overlooked because of the imperfect sensitivity of the nucleic acid testing (NAT). Globally understanding the humoral immunity in asymptomatic carriers will provide scientific knowledge for developing serological tests, improving early identification, and implementing more rational control strategies against the pandemic.

Measure

Utilizing both NAT and commercial kits for serum IgM and IgG antibodies, we extensively screened 11 766 epidemiologically suspected individuals on enrollment and 63 asymptomatic individuals were detected and recruited. Sixty-three healthy individuals and 51 mild patients without any preexisting conditions were set as controls. Serum IgM and IgG profiles were further probed using a SARS-CoV-2 proteome microarray, and neutralizing antibody was detected by a pseudotyped virus neutralization assay system. The dynamics of antibodies were analyzed with exposure time or symptoms onset.

Results

A combination test of NAT and serological testing for IgM antibody discovered 55.5% of the total of 63 asymptomatic infections, which significantly raises the detection sensitivity when compared with the NAT alone (19%). Serum proteome microarray analysis demonstrated that asymptomatics mainly produced IgM and IgG antibodies against S1 and N proteins out of 20 proteins of SARS-CoV-2. Different from strong and persistent N-specific antibodies, S1-specific IgM responses, which evolved in asymptomatic individuals as early as the seventh day after exposure, peaked on days from 17 days to 25 days, and then disappeared in two months, might be used as an early diagnostic biomarker. 11.8% (6/51) mild patients and 38.1% (24/63) asymptomatic individuals did not produce neutralizing antibody. In particular, neutralizing antibody in asymptomatics gradually vanished in two months.

Conclusion

Our findings might have important implications for the definition of asymptomatic COVID-19 infections, diagnosis, serological survey, public health, and immunization strategies.

     

非小细胞肺癌中p16 INK4／CDKN2基因的缺失和点突变

目的为了探讨周期素依赖性激酶４抑制因子基因（ｐ１６ＩＮＫ４）与肺癌发生的关系。方法采用双重ＰＣＲ－ＳＳＣＰ和序列分析方法，对３１例原发性非小细胞肺癌中ｐ１６ＩＮＫ４基因的存在状况进行了研究。结果３例存在ｐ１６基因缺失（３／３１），其中１例整个ｐ１６基因发生缺失，另两例则分别为外显子１和外显子２缺失；ｐ１６基因点突变２例（２／３１），外显子１和外显子２各一例；并发现在这五例基因异常样品中，４例（２例缺失和２例点突变）样品均为淋巴转移的非小细胞肺癌（４／２０）。结论提示ｐ１６基因失活和某些非小细胞肺癌（５／３１）的发生有关，并且可能发生在癌症的晚期。     

Involvement of protein kinase c in responses of rat dorsal horn neurons to mechanical stimuli and periaqueductal gray descending inhibition

 The effects of a protein kinase C (PKC) activator, 12-O-tetradecanoylphorbol-13-acetate (TPA), on the activity and periaqueductal gray (PAG)-induced inhibition of rat dorsal horn neurons of the lumbar spinal cord were tested. A microdialysis fiber was placed through the dorsal horn for the purpose of local application of pharmacological agents. Extracellular single-unit recordings from dorsal horn neurons were made near the microdialysis fiber. TPA was tested on nociceptive dorsal horn cells. There was a significant increase in the background activity and responses to ”brush”, with no changes in responses to pressure and pinch stimuli. TPA also significantly blocked the PAG-induced inhibition of responses to brush, press, and pinch. These effects were eliminated by coadministration of the PKC inhibitor NPC-15437. The solvent, which contained dimethyl sulfoxide, was also tested for its effect on the responses to peripheral mechanical stimuli and PAG-induced inhibition of the dorsal horn neurons. There were no significant changes. This experiment suggests that activation of the PKC second messenger system might increase the activity of dorsal horn neurons and their responses to peripheral stimuli; in addition, the phorbol ester attenuated the PAG-induced descending inhibition of the dorsal horn neuron activity. Received: 15 May 1996 / Accepted: 14 November 1996     

Behavioural factors associated with symptom outcomes in a primary care-based depression prevention intervention trial

BACKGROUND: A randomized trial of a primary care-based intervention to prevent depression relapse resulted in improved adherence to long-term antidepressant medication and depression outcomes. We evaluated the effects of this intervention on behavioural processes and identified process predictors of improved depressive symptoms. METHOD: Patients at high risk for depression recurrence or relapse following successful acute phase treatment (N=386) were randomly assigned to receive a low intensity 12-month intervention or continued usual care. The intervention combined education about depression, shared decision-making regarding use of maintenance pharmacotherapy and cognitive-behavioural strategies to promote self-management. Baseline, 3, 6, 9 and 12-month interviews assessed patients' self-care practices, self-efficacy for managing depression and depressive symptoms. RESULTS: Intervention patients had significantly greater self-efficacy for managing depression (P<0.01) and were more likely to keep track of depressive symptoms (P<0.0001), monitor early warning signs (P<0.0001), and plan for coping with high risk situations (P<0.0001) at all time points compared to usual care control patients. Self-efficacy for managing depression (P<0.0001), keeping track of depressive symptoms (P=0.05), monitoring for early warning signs (P=0.01), engaging in pleasant activities (P<0.0001) and engaging in social activities (P<0.0001) positively predicted improvements in depression symptom scores. CONCLUSIONS: A brief intervention designed to target cognitive-behavioural factors and promote adherence to pharmacotherapy in order to prevent depression relapse was highly successful in changing several behaviours related to controlling depression. Improvements in self-efficacy and several self-management behaviours that were targets of the intervention were significantly related to improvements in depression outcome.     

Recruitment of complement factor H-like protein 1 promotes intracellular invasion by group A streptococci

Numerous microbial pathogens exploit complement regulatory proteins such as factor H (FH) and factor H-like protein 1 (FHL-1) for immune evasion. Fba is an FHL-1 and FH binding protein expressed on the surface of the human pathogenic bacterium, Streptococcus pyogenes, a common agent of pharyngeal, skin, and soft-tissue infections. In the present study, we demonstrate that Fba and FHL-1 work in concert to promote invasion of epithelial cells by S. pyogenes. Fba fragments were expressed as recombinant proteins and assayed for binding of FHL-1 and FH by Western blotting, enzyme-linked immunosorbent assay, and surface plasmon resonance. A binding site for FHL-1 and FH was localized to the N-terminal half of Fba, a region predicted to contain a coiled-coil domain. Deletion of this coiled-coil domain greatly reduced FHL-1 and FH binding. PepSpot analyses identified a 16-amino-acid segment of Fba which overlaps the coiled-coil domain that binds both FHL-1 and FH. To localize the Fba binding site in FHL-1 and FH, surface plasmon resonance was used to assess the interactions between the streptococcal protein and a series of recombinant FH deletion constructs. The Fba binding site was localized to short consensus repeat 7 (SCR 7), a domain common to FHL-1 and FH. SCR 7 contains a heparin binding site, and heparin was found to inhibit FHL-1 binding to Fba. FHL-1 promoted entry of Fba(+) group A streptococci into epithelial cells in a dose-dependent manner but did not affect invasion by an isogenic fba mutant. To our knowledge, this is the first report of a bacterial pathogen exploiting a soluble complement regulatory protein for entry into host cells.     

病毒载量和T淋巴细胞计数在HIV感染者临床治疗疗效观察中的应用

目的 研究病毒载量检测和CD4^ 计数在评价人类免疫缺陷病毒(HIV)感染者疗效中的应用效果。方法 对HIV感染者临床病例73例进行了实验室和临床观察，其中包括6例鸡尾酒治疗病例、36例中药试验性治疗病例及31例未进行治疗的感染者。主要实验室指标包括血浆病毒载量及T淋巴细胞亚群计数。结果 在进行治疗后3个月时联合治疗组的病毒载量明显低于其他两组，并且在其后保持在很低的水平，CD4^ 计数水平明显高于其他两组并在其后持续升高。在整个观察期间，中药治疗组的病毒载量检测和CD4^ 计数水平与未治疗组差异无显著性，但在临床症状观察中中药治疗组较未治疗组有明显改善。结论 病毒载量检测和CD4^ 计数试验是评价抗HIV治疗疗效的有效方法。