Kinetics of the reaction of yolk cell surface in the loach to puncture and mechanic deformation

Circumferential and radial components of the yolk cell surface movements were measured in the loach embryos at the late blastula stage within 40–50 min after puncture or indentation by an obliquely directed glass rod. The yolk cell surface was preliminarily marked by coal particles. It was shown that even closely located regions of the surface differed markedly in the rate and direction of their movements. In the vicinity of puncture, the yolk cell surface at first contracted in both circumferential and radial directions and then widened, but did not reach the initial values. In more remote areas, this surface continued to contract in the circumferential direction, but was extended in the radial direction. The degree of its contraction along different radii was unequal. The reaction to oblique indentation was anisotropic: the closest area of the yolk cell surface, located along the direction of indentation, contracted in both circumferential and radial directions and formed a fold “leaking” onto the rod, while the opposite area contracted in the circumferential direction, but extended in the radial direction. A conclusion was drawn that the yolk cell surface is a multivariant mechanosensitive system. Its active responses to mechanical influences obey the same patterns as multicellular embryonic tissues.     

Growth of a human yolk sac tumor cell line with yolk sac-derived functions in selenium-supplemented chemically defined synthetic medium

Summary A human yolk sac tumor cell line, TG1, which was established from a testicular yolk sac tumor, was found to replicate continuously in a chemically defined medium supplemented with Na₂SeO₃ (ISRPMI). TG1 produced several plasma proteins and growth factors: albumin, alpha-fetoprotein (AFP), ferritin, carcinoembryonic antigen, beta-2-microglobulin, polyamine, neuron specific enolase, tissue polypeptide antigen, transferrin (Tf), epidermal growth factor, and platelet derived growth factor. By analysis of lectin (LcHA)-affinity electrophoresis, to examine the microheterogeneity of carbohydrate chains of synthetic glycoproteins, TG1 cells cultured with ISRPMI produced only LcHA reactive Tf and AFP based on core fucose attached to asparagine-linkedN-acetylglucosamine residues instead of LcHA-nonreactive Tf and AFP produced by TG1 cells cultured with fetal bovine serum (FBS)-containing medium.α1-6 Fucosyltransferase activity was significantly greater in the TG1 cells cultured with ISRPMI (39.9±1.5 pmol · h⁻¹ · mg⁻¹ protein) than cultured with FBS-containing media (18.2±1.2 pmol · h⁻¹ · mg⁻¹ protein). These results have indicated that the selective increase ofα1-6 fucosyltransferase occurred when the cells were cultured with the FBS-free synthetic media.     

Stimulation of bone resorption in organ culture by cholera toxin

Bone resorption in organ cultures of neonatal mouse calvaria was stimulated by choleragen (cholera enterotoxin) in a dose-related manner (0.5 to 5.0 ng/ml). Stimulation was potentiated by the cyclic nucleotide phosphodiesterase inhibitor isobutylmethylxanthine (4 μM) and was inhibited by human calcitonin (100 ng/ml), but not by indomethacin (0.7 μM), an inhibitor of the fatty acid cyclooxygenase. The action of choleragen on cyclic AMP accumulation and bone resorption was consistent with the known characteristics of this toxin: 1. choleragen increased cyclic AMP accumulation in bone cultures; 2. there was a lag period (20 – 120 min) prior to an increase in cyclic AMP accumulation following addition of choleragen; 3. incubation with choleragen for only 4 h stimulated bone resorption in the subsequent 44 h as much as did continuous incubation with choleragen for 48 h; and 4. choleragenoid, the biologically inactive toxoid, did not stimulate bone resorption in the concentration range in which choleragen was active. We conclude that activation of adenylyl cyclase and the subsequent increase in cyclic AMP production can stimulate bone resorption, and that cyclic AMP may, therefore, be involved in the enhanced bone resorption mediated by parathyroid hormone and other agents which increase cyclic AMP in bone.     

A pulsed NMR study of lipids,bound water and sodium ions in macroscopically-oriented lecithin/water lyotropic liquid crystal model membrane systems

The temperature and orientation dependence of pulsed NMR ‘free induction decay’ signals have been studied in detail for lipid bilayers macroscopically-oriented between glass slides. Results for the lipid molecules (¹H, ³¹P), bound water (²H₂O) and ions dissolved in the aqueous phase (²³Na) are presented. Bilayers of egg-lecithin, dimyristoyl lecithin and potassium oleate have been investigated. In the liquid crystal phase all the signals, including those from bound water and ions exhibit a |3 cos²? ? 1| dependence on orientation of the bilayer normal to the magnetic field. In the case of DML samples, some orientation dependence of both ¹H and ²H signals persists in the gel phase, indicating that the lipid molecules retain a degree of reorientational freedom about their long axes in this phase. At the gel-liquid crystal transition the ²H quadrupole spittings undergo a discontinuous change. Results are interpreted in terms of a model in which water molecules are bound to individual lipid head groups and reorient with them, while sodium ions are located in the aqueous channel between bilayers.     

Ferritin as an exogenous yolk protein in snails

Summary A main yolk component in the oocytes of the pulmonate snailPlanorbarius corneus L. has been isolated and identified as the iron storage protein ferritin by its ultrastructure, iron content, immuunological properties and behaviour in disc electrophoresis. As judged from acrylamide electrophoresis data and ultrastructural observations, yolk ferritin is an exogenous protein which is synthesised in the hepatopancreas and taken up by the oocytes by endocytosis.     

Ultrastructural study of oogenesis and yolk formation in an opisthobranch mollusc, Runcina

Runcina is a hermaphroditic opisthobranch mollusc of small size. It produces large eggs, rich in yolk substances, and it is thus ideal for studying the mechanisms of vitellogenesis. The rough endoplasmic reticulum and the Golgi apparatus appear to be involved in early build up of yolk precursors. Endocytotic vesicles carrying yolk proteins, taken up from the haemolymph, dominate yolk formation at a later stage. The findings presented in this study enhance the proposition of a dual pathway of auto- and heterosynthesis in yolk formation. It is not found that the yolk bodies in Runcina acquire lysosomal enzymes in order to digest the perivitelline fluid, as has been described for some pulmonates. The importance of the role played by the follicle cells in oocyte development is discussed.     

小儿肺热咳喘颗粒联合雾化吸入用乙酰半胱氨酸溶液对支气管肺炎患儿肺通气功能、炎症因子和免疫球蛋白的影响

摘要 目的：观察小儿肺热咳喘颗粒联合雾化吸入用乙酰半胱氨酸溶液对支气管肺炎患儿肺通气功能、炎症因子和免疫球蛋白的影响。方法：选择2019年9月-2023年1月期间合肥市第二人民医院收治的100例支气管肺炎患儿,采用双色球法将患儿分为对照组和研究组,各为50例。对照组患儿接受雾化吸入用乙酰半胱氨酸溶液,研究组患儿在对照组的基础上接受小儿肺热咳喘颗粒。对比两组临床症状、炎症因子水平[白细胞介素-6（IL-6）、降钙素原（PCT）、C反应蛋白（CRP）]、免疫球蛋白[免疫球蛋白（Ig）A、IgM、IgG]、肺通气功能指标[吸气时间（TI）、呼气时间（TE）、吸呼比（TI/TE）、达峰时间比（TPF%TE）、达峰容积比（VPF%VE）]和不良反应发生率。结果：与对照组相比,研究组的肺部湿啰音消失时间、咳嗽消失时间、咳痰消失时间、退热时间更短（P<0.05）。研究组治疗10 d后CRP、IL-6、PCT低于对照组（P<0.05）。研究组治疗10 d后IgA、IgM、IgG高于对照组（P<0.05）。研究组治疗10 d后VT、TI、TE、TI/TE、TPF%TE、VPF%VE高于对照组（P<0.05）。两组不良反应发生率对比未见差异（P>0.05）。结论：小儿肺热咳喘颗粒联合雾化吸入用乙酰半胱氨酸溶液治疗支气管肺炎,可有效缩短临床症状缓解时间,改善肺通气功能,降低炎症因子水平,调节免疫球蛋白,且安全性较好。