High-performance anion-exchange chromatography of ultraviolet-absorbing constituents of human urine

A 100-μl urine sample was chromatographed on a column packed with a strongly basic macroreticular anion-exchange resin (Diaion CDR-10, 5– μm diameter with a nominal 35% cross linkage). The elution was performed with a linear acetate gradient from 0 to 6.0 M at an average flow-rate of 0.72 ml/min and at an average pressure of 104 kg/cm². The relative standard deviation of retention times and peak height was ± 4% or less. The properties of the macroreticular anion-exchange resin, the effect of the particle size, the pH of acetate buffers, and the effect of the flow-rate of the eluent on the separation were investigated. Thirty three components of urine were then resolved and named.     

Targeting Interleukin-6: All the Way to Treat Autoimmune and Inflammatory Diseases

Interleukin (IL)-6, a cytokine featuring redundancy and pleiotropic activity, contributes to host defense against acute environmental stress, while dysregulated persistent IL-6 production has been demonstrated to play a pathological role in various autoimmune and chronic inflammatory diseases. Targeting IL-6 is thus a rational approach to the treatment of these diseases. Indeed, clinical trials of tocilizumab, a humanized anti-IL-6 receptor antibody have verified its efficacy and tolerable safety for patients with rheumatoid arthritis, Castleman''s disease and systemic juvenile idiopathic arthritis, resulting in approval of this innovative biologic for treatment of these diseases. Moreover, a considerable number of case reports and pilot studies of off-label use of tocilizumab point to the beneficial effects of tocilizumab for a variety of other phenotypically different autoimmune and chronic inflammatory diseases. Elucidation of the source of IL-6 and of mechanisms through which IL-6 production is dysregulated can thus be expected to lead to clarification of the pathogenesis of various diseases.     

Abortive Infection of L Cells by Influenza B Virus: Defect in Bud Formation

Host-dependent restriction of influenza B virus replication in L cells was analysed in comparison with productive infection in MDCK or 1–5C-4 cells. The synthesis and intracellular distribution of virus-specific proteins and the production of cytoplasmic ribonucleoproteins in nonpermissive L cells were similar to those in permissive MDCK cells. However, an electron microscopic study of infected L cells showed neither extracellular virions nor budding virus particles on the cell surface, in contrast to MDCK cells which produced numerous virus particles. PAGE analysis of the plasma membrane isolated from the cells demonstrated no significant difference in the composition of viral polypeptides between permissive 1-5C-4 and nonpermissive L cells. It was noted that the abortiveness of influenza B virus infection in L cells may be due to a defect in host cell function involved in the initiation of virus budding.     

Mechanisms of modulation of neuronal nicotinic receptors by substance P and OAG

Substance P is known to modulate neuronal nicotinicacetylcholine receptors (nAChRs) in the sympathetic nervous system.There are two conflicting proposals for the mechanism of this effect, an indirect action mediated by protein kinase C (PKC) and a direct interaction with receptor subunits. We studied the mechanisms of thiseffect in PC-12 cells. Substance P enhanced the decay of thenicotine-induced whole cell current. This effect was fast in its onsetand was not antagonized by guanosine5'-O-(2-thiodiphosphate), a G protein blocker, orstaurosporine, a nonselective PKC blocker. Staurosporine failed toreverse the inhibition by 1-oleoyl-2-acetyl-sn-glycerol (OAG), a synthetic diacylglycerol analog known to activate PKC. Theinhibitory effects of the peptide and OAG were preserved in excisedpatches, but substance P applied to the extra patch membrane wasineffective in the cell-attached patch configuration. We conclude thatsubstance P modulates neuronal nAChRs most likely by direct interactions with the receptors but independently from activation ofPKC or G proteins and that PKC does not participate in modulation by OAG.

     

Rate of DNA Synthesis during Meiotic Prophase in Lily Microsporocytes in the Presence of Deoxyadenosine and Nalidixic Acid

The rate and period of DNA synthesis during meiotic prophasewere examined using lily microsporocytes. Meiocytes at the earlyleptotene stage were cultured for discrete periods in the presenceof inhibitors of DNA synthesis, deoxyadenosine and nalidixicacid. Deoxyadenosine, which arrests meiotic development at theearly zygotene stage, markedly suppressed DNA synthesis to 35%of control at 2 mM. Nalidixic acid simply reduced the rate ofDNA synthesis, resulting in prolongation of the synthetic period.The relevance of DNA synthesis to meiotic development is discussed. (Received January 12, 1987; Accepted May 7, 1987)     

Chemical modification of a functional arginine residue of rat liver glycine methyltransferase

Rat liver glycine methyltransferase is inactivated irreversibly by phenylglyoxal in potassium phosphate buffer. The inactivation obeys pseudo-first-order kinetics, and the apparent first-order rate constant for inactivation is linearly related to the reagent concentration. A second-order rate constant of 10.54 +/- 0.44 M-1 min-1 is obtained at pH 8.2 and 25 degrees C. Amino acid analysis shows that only arginine is modified upon treatment with phenylglyoxal. Sodium acetate, a competitive inhibitor with respect to glycine, affords complete protection in the presence of S-adenosylmethionine. Acetate alone has no effect on the rate of inactivation. The value of the dissociation constant for acetate determined from the protection experiment is in good agreement with that obtained by kinetic analysis. Comparison of the amount of [14C]phenylglyoxal incorporated into the protein and the number of arginine residues modified in the presence and absence of protecting ligands indicates that modification of one arginine residue per enzyme subunit eliminates the enzyme activity, and this residue is identified as Arg-175 by peptide analysis. The arginine-modified glycine methyltransferase appears to bind S-adenosylmethionine as the native enzyme does, as seen from quenching of the protein fluorescence by S-adenosylmethionine. These results suggest the requirement of Arg-175 in binding the carboxyl group of the substrate glycine.     

Postglacial environmental change of the Pacific Ocean off the coasts of central Japan

Downcore changes in microfossil assemblages and oxygen isotope ratios in three piston cores recovered from the Northwestern Pacific, off central Japan, show that the subtropical Kuroshio front was located to the south of C-4 core site (Lat. 33° N) during the last glacial. The front then advanced northward, passing over the C-4 site and the C-6 site (34.6° N) at about 13 ka and 10 ka, respectively, and reached the C-1 core site (36° N) at about 7 ka. After 5.5 ka it retreated to the area between the C-1 and C-6 sites. A brief but significant cold event, the readvance of the cold Oyashio Current, is recognized between 11 and 10 ka in the two northern cores, but the current did not reach the southern C-4 site. A contemporaneous cold event is known in the North Atlantic, and the cooling was probably a global phenomenon likely to be associated with lowering of sea level. Contamination of isotopically light water is apparent between 14 and 11 ka in the marked change in isotopic composition of benthic foraminifers. Oxygen isotope ratios of planktonic foraminifers show that prior to the advance of the Kuroshio front, the surface water at these core sites was isotopically lighter than the Kuroshio water at that time.     

Mutagenicity of ptaquiloside, the carcinogen in bracken, and its related illudane-type sesquiterpenes II. Chromosomal aberration tests with cultured mammalian cells

The chromosomal aberration test using a Chinese hamster lung cell line (CHL) was carried out on ptaquiloside and its related compounds, hypoloside B, hypoloside C, illudin M and illudin S. Ptaquiloside induced chromosomal aberrations at doses as low as 4.5 μg/ml (0.0113 mM). The clastogenic effect was ph-dependent. The same activity was observed at a 90-fold higher dose at pH 5.3 in the culture medium compared with the activity at pH 74. or pH 8.0. Both hypoloside B and hypoloside C were also clastogenic at almost the same dose levels as that of ptaquiloside. Illudin M and illudin S were also potet clastogens and induced aberrations at much lower doses than ptaquiloside. These results suggest that the clastogenic effect is involved in the mechanism of carcinogenic potency of ptaquiloside in animals.     

Supraependymal cells and fibers in the third ventricle of the domestic chicken. A scanning electron microscopic study

Supraependymal cells, fibers and what are presumed to be neuronal bulb-like projections were found in the third ventricle of the domestic chicken with a scanning electron microscope. At least two types of supraependymal cells were found: neuron-like cells and phagocyte-like cells. The former were predominantly seen in the area of the paraventricular organ and infundibular recess. The latter were abundant on the ventricular surface of the median eminence and subfornical organ. Bulb or club-like projections thought to be the dendritic terminals of CSF-contacting neurons were observed in the area of the paraventricular organ and infundibular recess. Similar structures were observed at the preoptic recess as well. The supraependymal neuronal components found in the domestic chicken differed from those of mammals in several respects: 1. the wall of the third ventricle was devoid of supraependymal fibrous plexus except for that of the paraventricular organ; 2. bulb-like projections were abundant in the area of the paraventricular organ; 3. supraependymal neuron-like cells were unipolar or bipolar in appearance. These data underline the dissimilarity of the CSF-contacting neuronal system of birds and mammals.     

Effect of volume expansion on hemodynamic variables in nephrectomized dogs

We have previously demonstrated that blood pressure elevation by acute blood volume expansion is volume-dependent during the infusion period and resistance-dependent in the post-infusion period in normal anesthetized dogs, and that such an increase in blood pressure is associated with a potentiation of the pressor response to norepinephrine. To evaluate the possible renal contribution to these hemodynamic changes, blood volume expansion was performed for 1 h with dextran dissolved in lactated Ringer's solution (20 ml/kg) in 15 nephrectomized dogs. The mean blood pressure, cardiac output and total peripheral resistance at the end of infusion were 126%, 225% and 60%, respectively; 3 h after volume expansion they were 126%, 151%, and 92% respectively. However, in 4 dogs, there was an increase in mean blood pressure (138%) 3 h after volume expansion. This was thought to result from an increase in the total peripheral resistance (133%) associated with the recovery of cardiac output (106%). The pressor response to norepinephrine (0.5 microgram/kg) was potentiated after volume expansion. These results indicate that the handling of volume by the kidney contributed to the maintenance of an elevated level of cardiac output. However, nephrectomy did not seem to interfere with the hemodynamic switching of the causative factor for blood pressure elevation from increased cardiac output to increased total peripheral resistance. Neither was the potentiation of pressor response to norepinephrine affected.