Jagged1 in the portal vein mesenchyme regulates intrahepatic bile duct development: insights into Alagille syndrome

Mutations in the human Notch ligand jagged 1 (JAG1) result in a multi-system disorder called Alagille syndrome (AGS). AGS is chiefly characterized by a paucity of intrahepatic bile ducts (IHBD), but also includes cardiac, ocular, skeletal, craniofacial and renal defects. The disease penetration and severity of the affected organs can vary significantly and the molecular basis for this broad spectrum of pathology is unclear. Here, we report that Jag1 inactivation in the portal vein mesenchyme (PVM), but not in the endothelium of mice, leads to the hepatic defects associated with AGS. Loss of Jag1 expression in SM22α-positive cells of the PVM leads to defective bile duct development beyond the initial formation of the ductal plate. Cytokeratin 19-positive cells are detected surrounding the portal vein, yet they are unable to form biliary tubes, revealing an instructive role of the vasculature in liver development. These findings uncover the cellular basis for the defining feature of AGS, identify mesenchymal Jag1-dependent and -independent stages of duct development, and provide mechanistic information for the role of Jag1 in IHBD formation.     

Effect of certain professions on the structure of the cervical portion of the spine]

The roentgen-anatomical study of the cervical portion of the vertebral column (fluorography and roentgenography in 2 projections followed by morphometrical treatment) was performed in 603 representatives of different professions: turners, milling-machine operators, craftsmen, mechanicians, jugglers, engineers and constructors. The following facts were established: asymmetry of bodies CIV and CV of vertebra in turners and milling-machine operators; differently pronounced cervical lordosis in persons of different professions; specific features in the architectonics of the spongy substance of the cervical vertebra bodies.     

The structure of the background EEG of the rabbit in the high-frequency portion of the spectrum]

With the purpose of studying the character and structure of high frequency bioelectric activity of rabbits cerebral cortex in the state of calm alertness, the EEG ensembles of different areas of the cortex (sensorimotor, visual, acoustic) and dorsal hippocampus were studied with FFT method. A supposition was made about the presence of systemic organization of the background EEG in rabbits cerebral cortex, reflected, in particular, in the presence of determined components both of chaotic and rhythmic character having different degrees of manifestation. Heterogeneity was revealed in distribution of energies of spectral EEG components in the studied frequency ranges from 14.7 to 100 Hz with predominance of total specific energy value in the band of 14.7-60 Hz. In coherence functions of all the studied pairs of EEG leads rhythmic component, stable in time, was absent. Functions of the mean EEG coherence in the band of 61-100 Hz had significantly greater values in comparison with the values in the band of 14.7-40 Hz.     

Glucose infused through the portal vein enhances liver gluconeogenesis and glycogenesis from [3-14C]pyruvate in the starved rat

After a pulse of [3-14C]pyruvate, 24 hr starved rats were infused through the portal vein with two different doses of glucose (7.8 or 20.8 mg/min) or the medium, and blood was collected from the inferior cava vein at the level of the suprahepatic veins. The highest dose of glucose enhanced the appearance of [14C]glucose in blood from the 2nd to the 20th min after tracer delivery. It also enhanced production of [14C]glycogen and concentration of glycogen in the liver after 5 and 20 min. At 20 min of glucose infusion the appearance of [14C]glyceride glycerol in liver as well as liver lactate concentration and lactate/pyruvate ratio were increased. The low dose of glucose used enhanced liver values of [14C]glycogen, [14C]glycogen specific activity and glycogen concentration. Our results support the hypothesis that in the starved rat glucose is converted into C3 units prior to being deposited as liver glycogen and based on the liver zonation model (Jungermann et al., 1983) it is proposed that glucose stimulated gluconeogenesis by shifting the liver to the cytosolic redox state as a secondary consequence of increased glycolytic activity.     

The wall structure of the central vein of the human adrenal glands]

The wall structure of the vena centralis in the human adrenal gland was examined by light and electron microscopy. The longitudinal smooth muscle system in the wall of the central vein was found to be incomplete, eccentric, and located far from the intima. At the junction with smaller veins the muscle system increases in size so that a thickening protrudes the intima into the lumen. A structured intercellular substance of varying width is located between the endothelium and the smooth muscle system, and unmyelinated adrenergic nerve fibres extend to the endothelium. Vasa vasorum are found only in the periphery of the vascular walls. The findings are interpreted as follows: The construction of the vein walls in the medulla of the human adrenal gland acts as a protection against the excessive contractile effect of a small to medium concentration of noradrenalin from the adrenal medulla.     

The fine structure of smooth muscle cells and their relationship to connective tissue in the rabbit portal vein

Summary The smooth muscle of rabbit portal vein was studied by electron microscopy with particular emphasis on the mechanical linkage between the muscle cells and on the distribution of connective tissue.The media of this vein is composed of inner circular and outer longitudinal muscle layers which are orientated almost perpendicularly to each other. The muscle of the inner circular layer shows very irregular contours with much branching and anastomosing of the cytoplasmic processes, which often make membrane contacts with neighbouring cells to form an extensive network of cytoplasmic processes. The muscle cells of the outer longitudinal layer are arranged in densely packed bundles and are spindle-shaped, with no branching processes. Opposing dense areas from neighbouring cells, with variable gap distances (30–100 nm) and close membrane contacts (intermediate junctions) with a gap of 11 nm were observed in both circular and longitudinal muscle layers.In the terminal regions of muscle cells in both circular and longitudinal layers a specialized anchoring structure was present which was closely related to extracellular elastic tissue. Muscle cells in the longitudinal layer showed the most elaborate structure, the tapering end of the muscle cell showing a honeycomb-like structure penetrated by columns of connective tissue compounds. The functional implications of these structures are discussed.     

门静脉海绵样变大鼠门静脉氧化应激损伤的研究

目的:考察门静脉海绵样变性(CTPV,Cavernous transformation of portal vein)大鼠体内氧化应激的状态以及氧化应激对门静脉结构的影响。方法:采用门脉部分结扎法复制CTPV大鼠动物模型;通过测定门静脉内血浆超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活力来分析机体抗氧化能力,测定丙二醛(MDA)含量分析机体氧化能力;门静脉HE染色观察门静脉病理变化。结果:Sham组大鼠门静脉造影显示门静脉通畅,无曲张与扩张;门静脉病理学检查显示门静脉管腔无增大、内皮细胞光滑、中膜平滑肌层无增厚、外膜完整。CTPV组大鼠门静脉造影显示门静脉周围侧支循环形成,门静脉病理检查显示多个管腔大小不一、外形不规则血管腔,管腔之间为较狭窄的纤维性间隔,其内可见脂肪细胞、散在的淋巴细胞及肥大细胞等,门静脉管腔增大、血管内膜受损、内皮细胞脱落、中膜平滑肌增厚和血栓形成。与Sham组大鼠比较,CTPV组大鼠SOD、GSH-Px活性降低(93.79+8.87μU/L Vs103.05+8.07μU/L,P<0.05,157.44+26.46U/ml Vs709.09+83.21U/ml,P<0...