A note on a theoretical study of erythrocyte sedimentation in inclined tubes

The expression for the sedimentation rate in inclined tubes given by Nakamura et al (Nakamura, H. and Kuroda, K. Keijo J. Med. 8, 256-296, 1937) is improved to be applicable to the problem that the falling velocity of a particle from the top wall of the tube v' differs from the one from the interface between the particle free layer and the suspended layer v. The effects of the shape at the bottom of the tube and the increase in height of the layer closely packed with particles are taken into account.     

Comparison of plasma prostanoid levels in the human cord artery in normal and fetal distressed deliveries

Prostaglandin E2 (PGE2), thromboxane B2 (TXB2; as a stable metabolite of TXA2), prostaglandin F2 alpha (PGF2 alpha) and 6-keto-PGF1 alpha (as a stable end product of prostacyclin) have been measured by using specific radioimmunoassay in the plasma of the cord artery immediately after delivery before the cord was clamped. Plasma prostanoid concentrations in normal deliveries (n = 8, as controls) were 24.8 +/- 2.6 (PGE2), 246.8 +/- 37.0 (TXB2), 122.2 +/- 13.3 (PGF2 alpha) and 82.1 +/- 7.7 (6-keto-PGF1 alpha) respectively (pg/ml, mean +/- s.e). On the other hand, in fetal distressed deliveries showing continuous bradycardia (n = 6), they increased significantly to 275.4 +/- 20.1 (PGE2), 948.6 +/- 102.5 (TXB2), 218.0 +/- 21.4 (PGF2 alpha) and 1498.6 +/- 298.4 (6-keto-PGF1 alpha) respectively (pg/ml, mean +/- s.e, p less than 0.005). However, both PGF2 alpha/PGE2 and TXB2/6-keto-PGF1 alpha ratios declined significantly from 4.70 +/- 0.33 to 0.68 +/- 0.05 and from 3.07 +/- 0.37 to 0.68 +/- 0.12 respectively (mean +/- s.e, p less than 0.005) in the fetal distressed group compared with those of the controls. From these results, it may be concluded that the cord artery, which is known as the patent source for the production of PGE2 and prostacyclin, did exert a sufficiently strong reaction to overcome the undesirable haemodynamic changes to maintain the fetal well-being in utero.     

Bacteriocinlike killing action of a temperate bacteriophage phiBA1 of Bacillus aneurinolyticus.

A new temperate phage, phiBA1, was isolated from Bacillus aneurinolyticus, phiBA1 had an icosahedral head with a diameter of about 70 nm and a tail about 20 nm long and contained a circularly permuted, linear duplex DNA of about 38 x 106 daltons. This phage showed two activities: bacteriocin-like killing activity against five strains of B. aneurinolyticus and normal temperate phage activity against three other strains. phiBA1 killed sensitive cells by a single-hit process. After adsorption of phiBA1 to cells sensitive to killing, the content of intracellular ATP increased for the first 5 min and then gradually decreased. Phage DNA injected into the cell immediately after infection was degraded rapidly. Killing was also caused by heavily UV-irradiated phiBA1. Killing-resistant mutants showed normal adsorption of phiBA1 and normal injection of the DNA with its instantaneous restriction. Our results indicate that the killing action of phiBA1 is different from the phenomenon of abortive infection and suggest that the killing might be caused by a proteinaceous component of phiBA1.     

Wounding Inhibits Protein Synthesis yet Stimulates Polysome Formation in Aged, Excised Pea Epicotyls

Wounding of aged, previously-excised pea epicotyl segments byremoval of the basal 1–2 mm resulted in a rapid (beginningwithin 15 min) recruitment of monosomes on to polysomes andan even more rapid (maximal between 6–12 min) inhibitionof protein synthesis in the remaining tissue. This inhibitionof protein synthesis in vivo did not appear to be an artefactcaused by the removal of highly active tissue (e.g., callus,contaminating bacteria), since wounds inflicted at a site distantfrom the region analyzed still elicited the response, and proteinsynthesis in the 1–2 mm slices (normally discarded) wasinhibited even more strongly than it was in the remaining tissue.The proportion of radioactive methionine in nascent chains (boundto polysomes) increased, while the production of completed polypeptidesdecreased, after wounding. Cycloheximide, a known inhibitorof the ribosome translocation/release process mimicked someof the effects of wounding. We interpret the results to indicatethat the initial effect of wounding is to inhibit translationby inhibiting the ribosome translocation/release process, whereasthe subsequent recovery in protein synthesis is brought aboutpartly by a recovery in ribosome translocation/release and partlyby enhanced initiation. ¹ Present address: Harvard-MIT Division of Health Science andTechnology, MIT, Cambridge, Massachusetts 02139, U.S.A. ² Present address: Institute of Agricultural Environment Control,College of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama790, Japan. (Received May 26, 1986; Accepted August 4, 1986)     

Metabolism of S-adenosylmethionine in rat hepatocytes: transfer of methyl group from S-adenosylmethionine by methyltransferase reactions

Treatment of rats with a methionine diet leads not only to a marked increase of S-adenosylmethionine synthetase in liver, but also to the increase of glycine, guanidoacetate and betaine-homocysteine methyltransferases. The activity of tRNA methyltransferase decreased with the increased amounts of methionine in the diets. However, the activities of phospholipids and S-adenosylmethionine-homocysteine methyltransferases did not show any significant change. When hepatocarcinogenesis induced by 2-fluorenylacetamide progresses, the activities of glycine and guanidoacetate methyltransferases in rat liver decreased, and could not be detected in tumorous area 8 months after treatment. The levels of S-adenosylmethionine in the liver also decreased to levels of one-fifth of control animals at 8 months. The uptake and metabolism of [methyl-3H]-methionine and -S-adenosylmethionine have been investigated by in vivo and isolated hepatocytes. The uptake of methionine and transfer of methyl group to phospholipid in the cells by methionine were remarkably higher than those by S-adenosylmethionine. These results indicate that phospholipids in hepatocytes accept methyl group from S-adenosylmethionine immediately, when it is synthesized from methionine, before mixing its pool in the cells.     

Quantitative Isolation of Undegraded Polysomes from Aged Pea Tissue in the Absence of Contaminants and Artefacts

Undegraded polysomes were isolated successfully from aged peaepicotyls by grinding frozen tissue in at least 10 volumes ofbuffer A (0.2 M Tris-HCl, pH 8.5; 0.2 M sucrose; 60 mM KCl;30 mM MgCl₂), taking care to prevent the tissue from thawingprior to homogenization. Supposedly pure polysomes, derivedfrom the membrane-bound polysome fraction, were apparently contaminatedwith membranes, and contained polysomes clumped together vianascent chains. Problems with contaminants and artefacts werepartially alleviated by the use of polyoxyethylene tridecylether as a detergent replacing Triton X-100; further alleviatedby the use of large volumes of detergent-containing buffer toresuspend the membrane-bound polysome; and almost completelyeliminated by brief treatment of resuspended polysomes withprotease K. Optimal conditions for isolating polysomes fromaged tissue are given. ¹ Present address: Institute of Agricultural Environment Control,College of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama790, Japan. (Received April 24, 1985; Accepted September 2, 1985)     

Genetic polymorphism of human factor I (C3b inactivator)

Summary Genetic polymorphism of human factor I (C3b inactivator) has been described using polyacrylamide gel isoelectric focusing electrophoresis of neuraminidase-treated EDTA plasma samples followed by electrophoretic blotting technique. In 435 individuals three different common patterns were observed, and these were controlled by two common alleles at a single locus. The results of typing family material confirmed autosomal codominant Mendelian inheritance. Two common alleles were designated FI^*B and FI^*A, and gene frequencies were estimated to be 0.8931 and 0.1069 for FI^*B and FI^*A, respectively. The distribution of phenotypes fitted the Hardy-Weinberg equilibrium. Linkage studies failed to show close linkage between factor I and the major histocompatibility complex.     

Purification and characterization of a tuberculin-active substance from Mycobacterium bovis BCG

A new tuberculin-active substance, designated TAS-1D3, has been purified from the extract of Mycobacterium bovis BCG by precipitation at pH 4.2, ethanol fractionation, and column chromatography involving CM-cellulose, QAE-Sephadex A-25, Sephadex G-100, and Sephadex G-75. TAS-1D3 was homogeneous in polyacrylamide gel electrophoresis and positive in both Coomassie brilliant blue and periodic acid-Shiff staining, suggesting that TAS-1D3 is a glycoprotein. The molecular weight of TAS-1D3 was estimated to be 26,000 by gel filtration. In amino acid analysis, TAS-1D3 was distinctive in having proline as a dominant amino acid, and in that it lacked basic amino acids, sulfur-containing amino acids and aromatic amino acids. Moreover, TAS-1D3 was almost devoid of absorption at around 280 nm. In guinea pigs sensitized with BCG vaccine, the tuberculin activity of TAS-1D3 was about forty times more potent than that of purified protein derivative (PPD).     

Effects of glucagon on the redox states of cytochromes in mitochondria in situ in perfused rat liver

The effects of glucagon on the respiratory function of mitochondria in situ were investigated in isolated perfused rat liver. Glucagon at the concentrations higher than 20 pM and cyclic AMP (75 microM) stimulated hepatic respiration, and shifted the redox state of pyridine nucleotide (NADH/NAD) in mitochondria in situ to a more reduced state as judged by organ fluorometry and beta-hydroxybutyrate/acetoacetate ratio. The organ spectrophotometric study revealed that glucagon and cyclic AMP induced the reduction of redox states of cytochromes a(a3), b and c+c1. Atractyloside (4 micrograms/ml) abolished the effects of glucagon on these parameters and gluconeogenesis from lactate. These observations suggest that glucagon increases the availability of substrates for mitochondrial respiration, and this alteration in mitochondrial function is crucial in enhancing gluconeogenesis.     

Modulation of Schistosoma mansoni egg-induced granuloma formation. III. Evidence for an anti-idiotypic, I-J-positive, I-J-restricted, soluble T suppressor factor

Modulation of pathogenic egg-induced hepatic granuloma formation in chronically Schistosoma mansoni-infected mice is an immunoregulatory process. Adoptive transfer and in vitro studies have demonstrated that this suppression involves various T lymphocyte circuitries, and the participation of soluble suppressor factors has recently been noted in these systems. The present study has partially characterized a soluble suppressive activity extracted from the thymus glands of chronically infected mice (SmTsF) that modulates granuloma formation in acutely infected mice. The suppressive effect of SmTsF could be administered by multiple i.v. injections or by slow release from osmotic minipumps implanted i.p. Homologous and reciprocal transfers of SmTsF prepared from B10.A(3R) and B10.A(5R) donors indicated that SmTsF-induced suppression required homology between the donor and recipient at the I-J subregion of the major histocompatibility complex. Furthermore, the use of immunoabsorbents prepared with anti-I-Jk and anti-I-Jb sera demonstrated that CBA/J (H-2k) SmTsF was retained by, and could be recovered from, anti-I-Jk insoluble columns, but was unaffected by parallel treatment with anti-I-Jb sera. Subsequent immunoabsorbent studies showed that SmTsF did not bind to soluble egg antigenic (SEA) columns, and thus demonstrated a lack of idiotype, anti-antigen activity. However, columns prepared by using anti-SEA IgG from chronically infected syngeneic mice retained SmTsF suppressive activity, and it could be recovered by alkaline elution. These data are compatible with an interpretation that the suppressive activity expressed anti-idiotypic reactivity. Thus a thymus extract obtained from chronic, modulated, S. mansoni-infected mice can induce granuloma suppression in acutely infected mice. This activity is associated with an I-J determinant-bearing, possibly anti-idiotypic moiety or moieties. These observations further implicate some of the Ts cascades reported in other systems in the regulation of cell-mediated pathogenesis in chronic experimental schistosomiasis.