依据肝静脉断面特点的肝段三维重建

目的构建依据人体肝静脉管道系统断面结构特点的肝段数字化可视模型,为虚拟肝脏手术和数字解剖教学提供形态学依据。方法采用我所建立的数字化可视人体数据集获取的连续肝脏断面图像,通过体数据绘制及面数据绘制的方法,根据肝静脉断面图像的位置和特点,赋予肝段和肝内静脉不同的RGB颜色值进行结构提取,通过计算机三维重建来完成对肝段及肝内主支管道的可视化。结果肝脏数字化可视模型能够清晰显示肝段和肝脏主支管道的形态结构和边界毗邻。结论依据肝静脉断面结构特点的肝段三维重建可视化模型能准确反映出肝段和肝脏主支管道彼此间的形态结构和边界毗邻关系,为肝脏数字解剖教学、虚拟肝脏手术治疗提供理论基础和应用依据。     

胸段食管破裂的护理体会

目的探讨胸段食管破裂患者的正确有效护理模式。方法总结分析24例不同类型胸段食管破裂患者护理经验和体会。结果其中21例痊愈,住院时间9~83 d,3例死亡均为晚期患者。结论早期诊断治疗和持久有效的护理能挽救胸段食管破裂患者。     

Anatomy of the liver

The liver is the largest organ in the body. Its gross anatomical divisions comprise the right, left, caudate and quadrate lobes, which do not correspond with its functional division into eight hepatic segments, each with their own blood supply and biliary drainage. The porta hepatis transmits the hepatic artery, portal vein and right and left hepatic ducts (the portal triad), together with lymphatic and autonomic nerves. The venous drainage of the liver, directly into the inferior vena cava, comprises the right, left and middle hepatic veins, together with the small accessory hepatic veins.     

Value of a virtual hepatic segment model in assisting in the ultrasonic localization of intrahepatic lesions

Background During scanning of the right hypochondrium and right intercostal regions with an ultrasonic transducer,several ultrasonic images of oblique sections are obtained.It is still a challenge for ultrasonography to divide these nonconventional sections into an accurate hepatic segmentation pattern.The aim of this research was to investigate the value of the virtual hepatic segment model （VHSM） in assisting the ultrasonic localization of space-occupying hepatic lesions.Methods VHSM was constructed via 3D reconstruction according to the first Chinese visible human dataset.Preoperative ultrasonography,contrast-enhanced CT scan and VHSM techniques were performed in 100 patients with spaceoccupying focal lesions in the liver parenchyma for segmental localization.The results of these three techniques were compared with the operative findings.Results VHSM was successfully detected on 2D sectional images by 3D reconstruction through surface rendering and volume rendering.The model could simulate ultrasonic directions to conduct a virtual dissection on any section plane,and fine liver segmentation could be displayed in any virtual plane.In 100 patients,there were 112 liver space-occupying focal lesions distributed in 148 liver segmentations.Regarding the positioning accuracies for lesions of different sizes and the lesion segmental distribution accuracies estimated using the three methods mentioned above,ultrasonography exhibited a significantly lower accuracy than VHSM for the segmental localization of lesions （P ＜0.05）,and contrast-enhanced CT was not significantly different from ultrasonography plus VHSM （P ＞0.05）.Conclusion VHSM increased the accuracy of ultrasonic localization of space-occupying hepatic lesions,particularly in hepatic hypovascular regions.     

高功率微波对感光细胞蛋白结构影响的实验研究

目的研究高功率微波(high-power microwave,HPM)照射后感光细胞中膜蛋白分子结构的改变,探讨HPM的损伤机制。方法选取大鼠视网膜感光细胞外节层作为研究对象,通过对显微傅里叶变换红外光谱技术(FT-IR)图谱酰胺Ⅰ带中蛋白质二级结构的各吸收峰进行定量分析,观察HPM照后蛋白质分子结构的改变情况。结果 HPM照后外节出现了膜蛋白二级结构吸收峰的位移和吸收值的改变。结论 HPM照射可使视网膜感光细胞的膜蛋白质构象发生改变,导致蛋白质结构稳定性下降和蛋白生物功能的破坏。     

Re-evaluation of the expression of the gastric H,K-ATPase α subunit along the rat nephron

 Under normal conditions, the rat collecting duct displays an H,K-ATPase activity with kinetic and pharmacological properties very close to those of the gastric H,K-ATPase. However, whether the collecting duct H,K-ATPase and the gastric enzyme are identical remains controversial. Therefore, we re-evaluated the expression of the mRNAs encoding the gastric H,K-ATPase α subunit in the rat nephron. For this purpose, gastric H,K-ATPase mRNAs were quantitated by RT-PCR at the level of microdissected nephron segments using known amounts of gastric H,K-ATPase cRNA as external standards. Results indicate that gastric H,K-ATPase mRNAs are undetectable (<1 copy per cell) in the glomerulus and along the proximal tubule, thick ascending limb of Henle’s loop and collecting duct, although a faint expression (≈ 400 copies per μg total RNA) is measurable in whole–kidney preparations. Gastric H,K-ATPase mRNA is also absent along the nephron of K-depleted rats and of rats with chronic metabolic acidosis and alkalosis. Taken with other data from the literature, these results suggest that the collecting duct of normal rats might express an H,K-ATPase similar, but not identical, to the gastric isoform. Received: 29 October 1996 / Accepted: 21 November 1996     

Portal Venous Territories Within the Human Liver: An Anatomical Reappraisal

Subdivision of the human liver into eight portal venous segments (according to Couinaud) is largely established in the anatomical and clinical community. However, this concept is challenged by an increasing number of surgical and radiological reports. We reexamined the intrahepatic portal venous architecture to understand the inconsistencies published. For this purpose, we studied the livers of 20 deceased who had donated their body to the Anatomy Department. The organs were investigated by portal venous injection, subsequent liver corrosion, and analysis of the branching pattern. After a usual bifurcation of the portal vein (order 0 vessel) into a right and left branch (first order vessels), the number of second order branches observed was between 9 and 44, with an average of 20. This seemingly trivial matter of fact suggests that the human liver does not consist of the eight segments presumed, but of many more. Supposedly contradictory observations turn out to be explainable by differing combinations of this large number of territories, and not simply by anatomical variability. For practical surgical purposes, we conclude that the useful eight‐segment scheme needs conceptual reappraisal when a more realistic approach to the individual hepatic territoriality in the patients under consideration is demanded. We submit a “1‐2‐20‐concept” as a possible key. Anat Rec, 291:636–642, 2008. © 2008 Wiley‐Liss, Inc.     

Coupling of metabolic CO2 production to ion transport in isolated rat thick ascending limbs and collecting tubules

Metabolic CO₂ production from appropriate [U-¹⁴C]-labelled substrates (eitherl-lactate ord-glucose) was measured in single pieces of tubule as previously described (Le Bouffant et al. 1984). Changing the incubate osmotic pressure by mannitol addition resulted in an increase in oxidative metabolism which was more marked in outermedullary segments (MAL and MCT) than in cortical segments (CAL and CCT). Availability of metabolic substrate was not rate limiting under these conditions because FCCP addition (1 mol·l^–1) produced a marked rise in CO₂ production in these structures.Ouabain (1 mmol·l^–1) decreased by more than 50% the CO₂ production by CAL, MAL, CCT and MCT samples, indicating that the larger part of oxidative metabolism was coupled to active Na transport. Furosemide addition (10^–5 mol·l^–1) to CAL and MAL samples, or amiloride addition (10^–4 mol·l^–1) to CCT and MCT samples reduced the rate of CO₂ production to an extent almost similar to that obtained with ouabain, an observation suggesting that apical entry of Na⁺ was present in these non-perfused tubules.Finally, the effects of changing the concentration of either K⁺ or Cl^– was tested in CAL samples. K⁺ suppression greatly depressed the rate of CO₂ production. Replacement of chloride with sulfate also decreased this rate to an extent similar to that observed with furosemide. The CO₂ production increased in a sigmoid way (apparentK _a=41 mmol·l^–1, Hill coefficient=2.12) as a function of [Cl^–] in the incubate, suggesting that oxidative metabolism was coupled to bath chloride via the Cl^–-requiring Na entry along the 1 Na⁺–1K⁺–2Cl^– luminal contrasport system.     

Characterization of the high-conductance Ca2+-activated K+ channel in adult human skeletal muscle

Ca²⁺-activated K⁺ channels of a large conductance (BK_Ca) in human skeletal muscle were studied by patch clamping membrane blebs and by using the three microelectrode voltage-clamp recording technique on resealed fibre segments. Single-channel recordings in bleb-attached and inside-out modes revealed BK_Ca conductances of 230 pS for symmetrical and 130 pS for physiological K⁺ distributions. Open probability increased with membrane depolarization and increasing internal [Ca²⁺]. The Hill coefficient was 2.0, indicating that at least two Ca²⁺ ions are required for full activation. Kinetic analysis revealed at least two open and three closed states. An additional long-lived inactivated state, lasting about 0.5–20 s, was observed following large depolarizations, when extracellular K⁺ was lowered to physiological values. BK_Ca were blocked by three means: (1) externally by tetraethylammonium which reduced single-channel amplitude (IC₅₀ approx. 0.3 mM); (2) internally by polymyxin B which decreased the open probability (IC₅₀ approx. 5 g/ml); and (3) externally by charybdotoxin which caused long-lasting periods of inactivation (IC₅₀ <10 nM). Measurements on resealed fibre segments at physiological [K⁺] were in accordance with the single-channel data: only when intracellular [Ca²⁺] was elevated did charybdotoxin (50 nM) reduce the macroscopic membrane K⁺ conductance with depolarizing voltage steps.