核骨架/核基质结合区及其功能研究的进展

长期以来的研究只能用结合试验来证明核基质结合区(MARs)的存在,对其真正的功能了解甚少.直到最近,人们才发现了MARs的一些生物学活性,MARs参与襻环的形成和染色体的高级包装,在真核生物的转录调控和凋亡方面起到了重要作用.对MARs的生物学功能仍在进一步的研究中,本文主要就MARs的结构、在转录调控中的作用及其它一些研究进展作一综述.     

健康和病变人声带振动特性声门图

本文用多功能声门图仪测定了健康受试者(男46名,女34名)和不同喉病患者(男134名,女87名)声门图的波形及其特征参数。根据测出的正常声门图及其参数分布研究了恶性喉病变、声带麻痹、喉内关节病变、功能性声门发声障碍、声带息肉、声带小结、喉炎和早期喉病的临床声门图表现及其与声带振动模式变异之间的关系,并探讨了上述病变声门图的鉴别诊断指标和用声门图对喉病手术治疗、药物治疗和功能治疗的疗效进行定性和定量评价。研究结果证实:声门图方法能准确、定量、灵敏地反映声带振动模式及其变异;在喉病诊治中具有重要的应用价值。     

早搏联律间期缩短对血流动力学的影响

目的研究房性、室性早搏联律间期缩短与桡动脉图的关系,探讨早搏对血流动力学的影响。方法经心电图诊断为房性早搏48例及室性早搏51例,再应用心功能仪检查,通过信号处理技术对早搏桡动脉图形进行面积积分。结果①早搏桡动脉图积分面积提前率〉40%时最小,20%-40%时居中,〈20%时最大（P〈0.05）。②提前率相同情况下,左房与右房的早搏桡动脉图积分面积比较差异无统计学意义（P〉0.05）;左室与右室的早搏桡动脉图积分面积比较差异有统计学意义（P〈0.05）。③早搏时的桡动脉图积分面积最小,早搏前第一个窦性心搏居中,早搏后第一个窦性心搏最大（P〈0.05）。结论早搏对血流动力学的影响主要与早搏的联律间期长短有关,室性早搏还与其发生部位有关,早搏的代偿间歇,不能改善对血流动力学的影响。     

Shape of the myopic eye as seen with high-resolution magnetic resonance imaging.

We have obtained multislice magnetic resonance (MR) images of the eye and calculated ocular dimensions along the three cardinal axes: antero-posterior (A-P), equatorial, and vertical. We found no difference in the shape of hyperopic (average refractive error: +3.72 D) and emmetropic eyes, both of which had an equatorial diameter longer than the A-P and vertical diameters. Myopic eyes (average refractive error: -6.54 D) were larger than hyperopic eyes, and most had the same spheroelliptical shape as that of the emmetropic and hyperopic eyes. The results suggest that during myopic progression an overall enlargement or a radial volume expansion has occurred.     

Prognostic role of alveolar-arterial oxygen pressure difference in acute pulmonary embolism.

BACKGROUND: This study investigated the utility of the alveolar - arterial oxygen pressure difference (AaDO (2)) in predicting the short-term prognosis of acute pulmonary embolism (PE). METHODS AND RESULTS: This study retrospectively enrolled 114 consecutive patients with acute PE, diagnosed by either spiral computed tomography or high probability ventilation - perfusion lung scans. During the first 24 h of admission, all patients had initial artery blood gas collected under room air. Patient exclusion criteria were chronic lung disease, septic emboli, and moderate and low probability lung scans. Patients were assigned to 2 groups based on either 30-day death or a 30-day composite event. Receiver operating characteristic analyses was used to determine the AaDO(2) cut-off value for predicting primary and composite endpoints. Statistical analysis demonstrated significant differences in AaDO(2) between the 30-day composite endpoint group and the 30-day composite event-free survival group (p=0.012). The AaDO(2) had a strong trend between the 30-day death group and the survival group (p=0.062). The best cut-off value for AaDO(2) was 53 mmHg and using this, the positive predictive value for 30-day death was 25% and the negative predictive value was 92%. For the 30-day composite endpoint, the positive predictive value for AaDO(2) was 35%, and the negative predictive value was 84%. In this study, thrombocytopenia was also an indicator of poor prognosis for patients with acute PE. CONCLUSION: The AaDO(2) measurement is a highly useful and simple measurement for predicting short-term prognosis in patients with acute PE. It has high negative predictive value and moderate positive predictive value for 30-day death and 30-day composite event. Aggressive thrombolytic treatment strategies should be considered for patients with an initial poor prognostic parameter (ie, AaDO(2) >or=53 mmHg).