DNA聚合酶β可能参与了更广泛的细胞反应并引起遗传不稳定

近年来有关真核细胞中ＤＮＡ聚合酶的研究迅速增多。 1985年前 ,确认的ＤＮＡ聚合酶只有 3种 :聚合酶α、β以及线粒体聚合酶γ。时至今日已至少发现了 14种ＤＮＡ聚合酶 ,包括聚合酶α、β、γ、δ、ε、ζ、η、θ、ι、κ、λ、μ、ＲＥＶ1及ＭＵＳ30 8,在真核细胞ＤＮＡ的复制、修复、跨损伤合成、ＤＮＡ重组以及细胞周期调控等多种重要的生物代谢过程中发挥重要作用[1] 。在一定程度上 ,细胞内的各种聚合酶均有其独特的功能和作用领域。如具有引物酶活性的聚合酶α的作用是启动ＤＮＡ复制并合成ＲＮＡ -ＤＮＡ引物 ;聚合酶δ和ε是主要…     

Blogging Your PACS

Acquiring, implementing, and maintaining a picture archiving and communication system (PACS) is an enduring and complex endeavor. A large-scale project such as this requires efficient and effective communication among a large number of stakeholders, sharing of complex documentation, recording ideas, experiences, and events such as meetings, and project milestones to succeed. Often, mass-market technologies designed for other purposes can be used to solve specific complex problems in healthcare. In this case, we wanted to explore the role of popular weblogging or “blogging” software to meet our needs. We reviewed a number of well-known blog software packages and evaluated them based on a set of criteria. We looked at simplicity of installation, configuration, and management. We also wanted an intuitive, Web-based interface for end-users, low cost of ownership, use of open source software, and a secure forum for all PACS team members. We chose and implemented the Invision Power Board for two purposes: local PACS administrative purposes and for a national PACS users' group discussion. We conclude that off the shelf, state-of-the-art, mass-market software such as that used for the currently very popular purpose of weblogging or “blogging” can be very useful in managing the variety of communications necessary for the successful implementation of PACS.     

CT三维重建在侧颅底的应用研究

目的 探讨CT三维重建在侧颅底的应用价值。方法 15例健康成人在Picker5000全身CT机上行连续轴位扫描，将扫描获得的原始数据输入Voxel Q图像后处理工作站，采用表面阴影法(surface shaded display，SSD)进行三维重建。结果 侧颅底CT三维重建能清楚显示正常侧颅底孔、裂和重要的骨性标志。重建的结构可整体显示或切割后单独显示，两均可在三维空间绕任意轴旋转任意角度。结论 三维CT能立体而直观的显示侧颅底骨性结构，有利于侧颅底外科手术方案的设计。     

The development of spatial capacity in piloting and dead reckoning by infant rats: use of the huddle as a home base for spatial navigation

Two forms of spatial navigation, piloting using external cues and dead reckoning using self-movement cues, are manifest in the outward and homeward trips of adult rats exploring from a home base. Here, the development of these two forms of spatial behavior are described for rats aged 14-65 days using a new paradigm in which a huddle of pups or an artificial huddle, a small heat pad, served as a home base on an open circular table that the rats could explore. When moving away from both home bases, the travel distance, path complexity, and number of stops of outward trips from the home base increased progressively with age from postnatal day 16 through 22. When returning to the home bases, the return trips to the home base were always more direct and had high travel velocities even though travel distance increased with age for the longest trips. The results are discussed in relation to the ideas that: (1) the pups pilot on the outward portion of their excursion and dead reckon on the homeward portion of their excursion, and (2) the two forms of navigation and associated spatial capacity are interdependent and develop in parallel and in close association with locomotor skill.     

Ventral medulla pHi measured in vivo by 31P NMR is not regulated during hypercapnia in anesthetized rat

Chemoreceptors in the ventral medulla contribute to the respiratory response to hypercapnia. Do they ‘sense’ intracellular pH (pH_i)? We measured pH_i in the ventral medulla or cortex (control) using ³¹P-NMR obtained via a novel 3×5 mm² surface coil in anesthetized rats breathing air or 7% CO₂. During air breathing over 240 min, pH_i decreased slightly from 7.13±0.02 to 7.05±0.02 (SEM; n=5; 2 cortex, 3 ventral medulla). During 180 min of hypercapnia, cortical pH_i (n=4) decreased from 7.17±0.02 to 6.87±0.01 by 90 min and recovered by 150 min. Ventral medulla pH_i showed no such regulation. It decreased from 7.11±0.02 to 6.88±0.02 at 90 min and recovered only after cessation of hypercapnia (n=5), results consistent with pH_i being the chemoreceptor stimulus. However, non-chemoreceptor neurons that contribute to our medullary NMR signal also do not appear to regulate pH_i in vitro. Regional differences in pH_i regulation between cortex and ventral medulla may be due to both chemosensitive and non-chemosensitive neurons.     

Fossa navicularis: anatomic variation at the skull base

The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were <2 mm in depth and the other 14 had a depth of >/=2 mm. Of the 525 patients, 16 (3.0%) were identified as having a fossa navicularis in CT images. Evaluation of MRIs showed no soft tissue lesions in any of these patients. Comprehensive anatomic details of the fossa navicularis have not been reported in the literature. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base.     

Anatomical variations of the ten triangles around the cavernous sinus

The dimensions of the 10 triangles around the cavernous sinus were measured to define the anatomical characteristics of the triangles and to compare their consistency in shape and area. Twelve tissue blocks containing the bilateral cavernous sinuses and medial two-thirds of the middle cranial fossae were obtained from Japanese adults at autopsy, fixed to a stereotactic frame, and examined with an operative microscope. The dimensions of each triangle were measured with calipers and compared, based on the same point and border. The anteromedial triangle and the superolateral (Parkinson's) triangle were more consistent in shape than the paramedial and oculomotor triangles, but the oculomotor triangle was larger in area than these other triangles. The posteromedial (Kawase's) triangle was more consistent in shape and larger than the anterolateral, lateral, and the posterolateral (Glasscock's) triangles. The anteromedial and superolateral (Parkinson's) triangles are important for the combined epi- and subdural approach to cavernous sinus lesions. The posteromedial (Kawase's) triangle is important for gaining access to the posterior cranial fossa from the middle cranial fossa.     

Hemoglobin-oxygen affinity in anemia

Summary In blood of 21 anemic patients and 8 normal subjects (N) thre oxygen dissociation curves each were measured at different pH values to calculate Bohr coefficients after acidification with CO₂ (BC_{CO 2}) or fixed acid (BC_FA), and other important parameters of oxygen affinity. The patients had either low hemoglobin or red cell production (L:n=11, 7.3 g/dl Hb) or high erythrocyte production combined with high loss (H:n=10, 7.8 g/dl Hb). The standard half saturation pressure P₅₀ (pH 7.4, 37°C) was equally elevated in both anemic groups (L:30.5, H:30.8, N:26.7 mmHg), as well as the diphosphoglycerate concentration (DPG) (L:18.7, H:18.6, N:12.7 mol/g Hb). The red cell pH of the anemics was lower than for the N (approximately 0.045 units) causing part of the difference in P₅₀. Hill's ntended to high values in the anemics except at low O₂-saturation in the H. For BC_{CO 2} no significant difference among the groups was observed. BC_FA, however, increased in the H at low S_{O 2} compared to the N and L. The cause for most of the changes in hemoglobin oxygen affinity in anemics was the high [DPG]. The combination of high P₅₀ and high n value as in the L seems to be most advantageous for tissue oxygenation.The measurements were performed during a stay as visiting professor at the Universidad del Valle, supported by Deutscher Akademischer Austauschdienst VS 931 509 0013     

医疗绩效管理中实施PDCA循环的效果分析

目的对比分析实施PDCA循环前后医疗绩效管理的效果。方法医院每季度进行一次绩效管理考核,分为核心制度、病历质量、用药情况、耗材情况和医疗效率5个维度。2019年第一季度绩效管理开始引入PDCA循环,以第一季度各维度得分作为基础值,对比分析引入PDCA循环前后各维度得分,以手术科室为例,进行统计分析。结果核心制度、病历质量、耗材情况维度得分比较,均P<0.05,差异具有统计学意义;用药情况、医疗效率维度得分比较,均P>0.05,但各季度得分相比基础值均逐渐升高,第四季度与基础值比较差异具有统计学意义(P<0.05)。结论医疗绩效管理中实施PDCA循环,能有效提升管理水平,促进医疗质量螺旋上升。