Local adjuvants: the influence of sodium dodecylbenzene sulphonate on immunization with aerosolized antigen.

Guinea-pig respiratory and serum antibody responses were enhanced following exposure to aerosols of bovine IgG2 dissolved in solutions of sodium dodecylbenzene sulphate (SDBS). Enhanced response was seen in both primary and secondary immunization. Cell-mediated immune response (indirect macrophage migration influencing test) was not altered by SDBS. Results are discussed with a view to the possible utility of SDBS as adjuvant for prophylactic immunization.     

Modulation of antibody synthesis by an anti-tumour alga

Summary An unicellular alga,Chlorella pyrenoidosa, which had been reported to protect C₃H mice against sarcoma BP8, is shown, when injected in Freund's incomplete adjuvant, to modulate the antibody synthesis induced by immunization with a hapten-carrier complex.C. pyrenoidosa appeared to be able to initiate an antigenic competition between hapten and carrier determinants of the antigen molecule during antibody synthesis, and thus it could be speculated thatC. pyrenoidosa modulates the immune response at the macrophage level.Acknowledgments. This work was supported by the Secrétariat d'Etat aux Universités and by the DGRST, grant No. 77.71347.     

泛昔洛韦与十二烷基苯磺酸钠对盐水中黄铜的协同缓蚀效应研究

采用失重法、极化曲线法、交流阻抗法研究泛昔洛韦与十二烷基苯磺酸钠（SDBS）对黄铜在3．0％NaCl介质中的缓蚀作用。结果表明：当泛昔洛韦浓度为0．40g／L、SDBS浓度为0．35g／L时,其复配缓蚀效率达到93．5％。泛昔洛韦和SDBS对黄铜的缓蚀机理分析表明,泛昔洛韦在铜舍金表面通过物理与化学吸附共同作用形成保护膜,与SDBS发挥了极好的协同作用,阻碍Cl^-对铜的侵蚀,实现了对铜的高效保护。     

IgG purification to measure the level of an iodinated thyroglobulin peptide,the 3,5,3′,5′ tetraiodo-l-tyrosyl-l-tyrosine in human serum

Summary Antibodies reacting with 3,5,3,5 tetraiodo-l-tyrosyl-l-tyrosine (I₂Tyr-I₂Tyr) were elicited in rabbits by immunization with an oxidized yeast conjugate coupled with I₂Tyr-I₂Tyr. Ion-exchange chromatography was used to purify immunoglobulins, in order to improve the specificity in measurement of I₂Tyr-I₂Tyr level in patient serum. IgG binding capacity versus I₂Tyr-I₂Tyr was considerably increased after immunoglobulin purification.Acknowledgments. The authors with to thank Mrs M. Ollier for her valuable technical assistance.     

Mécanisme d'action du chloramphénicol dans l'inhibition de la production d'anticorps induite par de différents types d'antigènes

Summary Chloramphenicol (CAF) administered to rabbits during the whole period of immunization, is able to suppress almost completely the antibody response against horse serum albumin and globulins (HSA, HSG) andEscherichia coli: on the other hand, it does not inhibit antibody response to heterologous RBC. The possible mechanism of the inhibiting action of the CAF in antibody response to HSA, HSG andE. coli is discussed, and some hypotheses are put forward on the possible reasons for the different behaviour of CAF on the immune response induced by heterologous RBC.     

Aging and endothelin-1 induced vascular contractions

Summary Contractions produced by endothelin-1 (0.3–30 nM) have been investigated in aorta, renal arteries and mesenteric arteries from 2- and 24-month-old Sprague-Dawley rats. In senescent rats the EC₅₀ values of endothelin-1 for aorta and renal artery were significantly increased (aorta: from 6.2 to 12 nM; renal artery: from 5.2 to 7.8 nM). For mesenteric artery the EC₅₀ value (4.3 nM) was unchanged by aging, whereas the maximal contractile response to endothelin-1 was enhanced (from 8.3 to 11.7 mN). In contrast, there was no significant age-related difference in the maximal endothelin-1 response of aorta and renal artery. The present data demonstrate a reduced sensitivity for aorta and renal artery and an enhanced maximal response to endothelin-1 in the mesenteric artery in senescent rats.     

Production and characterization of antibodies cross-reactive with major aflatoxins

Antibodies cross-reactive with 4 major aflatoxins were demonstrated three weeks after immunization of rabbits with an immunogen which was prepared by conjugating aflatoxin B₃ to bovine serum albumin. Aflatoxin B₃ was first converted to its hemisuccinate before conjugation to the protein. Tritiated aflatoxin B₁ (AFB₁) was used as the marker ligand both for antibody titer determination as well as for analysis of antibody specificity. Competitive RIA revealed that the antibodies have good cross-reactivity with aflatoxins B₁, B₂, G₁, and G₂ when tritiated AFB₁ was used as the marker ligand. The concentrations causing 50% inhibition of binding of³H-AFB₁ to the antibodies by unlabeled aflatoxins B₁, B₂, G₁, G₂ and B₃ were found to be 0.25, 3.34, 0.32, 4.0 and 0.53 ng/assay, respectively. The antibodies could be used for simultaneous analysis of aflatoxins B₁ and G₁, two of the most important toxic metabolites produced byAspergillus flavus andA. parasiticus.     

Production and characterization of antibody against aflatoxin M1

Summary Antibody against aflatoxin M₁ was obtained after immunization of rabbits with bovine serum albumin-afla M₁ oxime conjugate. The antibody has greatest binding efficiency for afla M₁, and was less efficient for afla B₁. Cross-reaction of antibody with aflatoxin Q₁, aflatoxicol, and aflatoxin B_2a was weak. Aflatoxin B₂, G₁, and G₂ and afla B₁-guanine adduct showed almost no cross-reaction with the antibody. The sensitivity of the binding assay for aflatoxin M₁ detection is in the range of 1–10 ng per assay. Detailed methods for the preparation of the conjugate, production of immune serum, and methods for antibody determination are described.Supported by the College of Agricultural and Life Sciences, North Central Regional project NC-129, the University of Wisconsin-Madison, and by Public Health Service research grant number CA 15064 from the National Cancer Institute, NIH.The authors wish to thank Dr R.C. Garner for providing aflatoxin-B-guanine adduct, and Dr Dennis H. Hseih for providing aflatoxicol and aflatoxin Q₁.     

Efficacy of tumor cell vaccine after incorporating monophosphoryl lipid A (MPL) in tumor cell membranes containing tumor-associated ganglioside

Murine B16 melanoma expresses the ganglioside. GM₃. GM₃ shed from tumor cells is immunosuppressive and promotes tumor growth¹. Reduction or elimination of the shed GM₃ could be therapeutic, and the anti-GM₃ antibodies may reduce and clear the shed ganglioside. To test this hypothesis, mice were challenged with tumor cells, with or without inducing anti-GM₃ antibody response. Since gangliosides are poor immunogens and T-cell independent antigens, an adjuvant (monophosphoryl lipid A (MPL), a non-toxic lipid A ofSalmonella), directed against B-cells, was employed. MPL was incorporated onto liposomes and into the surface membrane of B16 mouse melanoma cells; both are rich in GM₃. C57BL/6J mice immunized with MPL-liposomes or MPL-B16 cells responded with elevated levels of anti-GM₃ IgM. Non-immunized mice or mice immunized with B16 cells alone or ganglioside GM₃ alone (without MPL) elicited poor anti-GM₃ IgM response, confirming the GM₃'s immunologic crypticity and MPL's immunopotentiating effect. MPL's immunopotentiating effect was improved by coupling it to melanoma cell membranes C57BL/6J mice were immunized with irradiated B16 alone or MPL alone or MPL-conjugated irradiated B16. After three weekly immunizations, each mouse received a challenge dose of viable syngeneic B16. Neither MPL alone nor B16 alone had a significant effect on tumor growth or host survival; however, administration of MPL-conjugated B16 cells significantly prevented tumor growth and prolonged survival. Our results indicate that MPL-incorporated B16 cells augment the anti-GM₃ IgM response, which may reverse GM₃-induced immunosuppression by eliminating tumor-derived GM₃, and restore immunocompetence.     

The response of Ca-mediated action potentials and contractile activity in mammalian ventricular myocardium towards alkalosis

Summary Alkalosis (pH 7.8) produced by reduction of CO₂ concentration augmented both upstroke velocity of Ca action potentials and isometric contractile force of mammalian heart muscle. If the increase of pH to 7.8 was achieved by a raise of HCO₃ concentration (with simultaneous reduction of CO₂ concentration), the positive inotropic response was not accompanied by an augmented Ca current. Obviously, the well-known positive inotropic effect of alkalosis does not only depend upon the enhancement of transmembrane Ca influx during excitation, but can be mediated alone by affecting intracellular Ca movements as well.     

Renal vascular reactivity to ATP in hyper- and hypothyroid rats

The effects of adenosine triphosphate (ATP) on the renal vasculature of isolated kidneys from control, hyper- and hypothyroid rats were characterized. ATP responsiveness was evaluated in basal tone and in raised tone (phenylephrine 10^–6 M) preparations. These responses were compared with those obtained with barium chloride or sodium nitroprusside (SNP), used respectively as nonreceptor agonists for vasoconstriction or vasodilation. In preparations at basal tone, ATP produced dose-related vasoconstriction, which was increased in hyperthyroid kidneys, and was severely attenuated in kidneys from hypothyroid rats. In raised tone preparations from control rats ATP produced a dual response: vasoconstriction at low doses, which declined with increasing doses to give way to vasodilator responses; biphasic responses were found in some kidneys. Hyperthroid kidneys showed increased pressor responses and a vasodilator response similar to those seen in kidneys from control rats. However, in hypothyroid kidneys the vasodilator response was abolished. The responses to barium chloride and to SNP were significantly increased and decreased in hyper- and hypothyroid kidneys, respectively; vasoconstrictor responses to SNP were also found in hypothyroid kidneys. Hence the abnormal responses to ATP observed in both thyroid dysfunctions may be partially explained by unspecific alterations in the contractile machinery of the renal vasculature in these kidneys. However, ATP responsiveness (vasoconstriction at low tone and vasodilation at raised tone) was more severely affected in hypothyroid kidneys, suggesting that purinergic (P_2X and P_2Y) receptor activity may be decreased in these organs.     

Differential sensitivity of the two phases of ear artery contraction to intimal and adventitial norepinephrine

Summary The biphasic contraction of the rabbit ear artery to norepinephrine (NE) was investigated in the normal (adventitial stimulation) and the everted (intimal stimulation) segment of ear artery. The 2nd phase response showed an intimal ED₅₀ of 8.2×10^–8 M which was significantly (p<0.05) lower than the adventitial ED₅₀ of 42.6×10^–8 M. This difference was abolished by inhibition of neuronal and extraneuronal uptake for NE. The 1st phase response also showed an ED₅₀ for the intimal stimulation (6.9×10^–8 M) which was significantly (p<0.05) lower than adventitial (65.5×10^–8 M). This difference was reduced but not abolished by NE uptake inhibition. This suggsets that some feature of the adrenergic neuroeffector apparatus is asymmetrically arranged to favor fast responses to blood borne NE.Supported by American Heart Association-Greater Los Angeles Affiliate Grant No. 602. We wish to thank Dr John Bevan and Dr Alasdair MacLean for helpful advice.     

Inhibition of human platelet lipoxygenase by cyanide

Summary Potassium cyanide inhibited the lipoxygenase activity of a human platelet cytosolic fraction in a concentration-dependent manner (ID₅₀=2 mM). The inhibition was monitored by spectrophotometry (conjugation of diene bonds at 236 nm), by chromatography (inhibition of formation of 12-hydroperoxy eicosatetraenoic acid) as well as by measuring suppression of oxygen consumption. The lipoxygenase activity of intact platelets was also inhibited by KCN as evidenced by the reduction in 12-hydroxy-eicosatetraenoic acid formation in response to thrombin.Acknowledgments. This work was supported in part by NIH grant HL-14890. D.A. was a recipient of the Pharmaceutical Manufacturers Association Advanced Pre-Doctoral Fellowship.     

The action of the peptidoleukotriene LTD4 on intracellular calcium in rat mesangial cells

The dose-dependent effect of CGP 45715A on the LTD₄-induced Ca²⁺ response of glomerular mesangial cells has been studied. Our results demonstrate that the LTD₄-dependent increase in the cytosolic Ca²⁺ concentration primarily involves an InsP₃-mediated release of Ca²⁺ from intracellular storage sites and to a minor extent an enhanced influx of Ca²⁺ through receptor-operated Ca²⁺ channels located in the plasma membrane. The action of CGP 45715A on the Ca²⁺ response is an inhibitory one and is convincingly explained by a displacement of LTD₄ from its receptor site(s). The contractile effect of LTD₄ on pulmonary smooth muscle is proposed to be mainly caused by a receptor-mediated hydrolysis of phosphatidylinositol-4,5-bisphosphate.     

Étude de la compétition antigénique chez des souris thymectomisées à la naissance

Summary The injection of horse red blood cells into the mouse 4 days before immunization with sheep red blood cells produces an inhibition of the primary response against sheep red blood cells. If the animal is thymectomized at birth, this antigenic competition does not occur. These findings do not permit a choice between the two hypotheses about antigenic competition.     

P2Y<Subscript>2</Subscript> receptor modulates shear stress-induced cell alignment and actin stress fibers in human umbilical vein endothelial cells

Endothelial cells release ATP in response to fluid shear stress, which activates purinergic (P2) receptor-mediated signaling molecules including endothelial nitric oxide (eNOS), a regulator of vascular tone. While P2 receptor-mediated signaling in the vasculature is well studied, the role of P2Y₂ receptors in shear stress-associated endothelial cell alignment, cytoskeletal alterations, and wound repair remains ill defined. To address these aspects, human umbilical vein endothelial cell (HUVEC) monolayers were cultured on gelatin-coated dishes and subjected to a shear stress of 1 Pa. HUVECs exposed to either P2Y₂ receptor antagonists or siRNA showed impaired fluid shear stress-induced cell alignment, and actin stress fiber formation as early as 6 h. Similarly, when compared to cells expressing the P2Y₂ Arg-Gly-Asp (RGD) wild-type receptors, HUVECs transiently expressing the P2Y₂ Arg-Gly-Glu (RGE) mutant receptors showed reduced cell alignment and actin stress fiber formation in response to shear stress as well as to P2Y₂ receptor agonists in static cultures. Additionally, we observed reduced shear stress-induced phosphorylation of focal adhesion kinase (Y397), and cofilin-1 (S3) with receptor knockdown as well as in cells expressing the P2Y₂ RGE mutant receptors. Consistent with the role of P2Y₂ receptors in vasodilation, receptor knockdown and overexpression of P2Y₂ RGE mutant receptors reduced shear stress-induced phosphorylation of AKT (S473), and eNOS (S1177). Furthermore, in a scratched wound assay, shear stress-induced cell migration was reduced by both pharmacological inhibition and receptor knockdown. Together, our results suggest a novel role for P2Y₂ receptor in shear stress-induced cytoskeletal alterations in HUVECs.     

Unique sex chromosome mediated behavioral response specificity of hybrid male European corn borer moths

Unlike the narrow response windows exhibited by the parent races, hybrid male European corn borers resulting from crosses of the E and Z races respond to a wide range of sex pheromone blends. The F₁ response profile consists of some individuals that respond to both the Z pheromone and the 6535 E/Z blend produced by F₁ females. Some F₁ males fail to respond to any blend and some do not respond as broadly as others. The hybrid male populations, however, are not tuned optimally to the pheromone blend produced by F₁ females and there is no coupling of F₁ blend production and response.     

Systemic oxygen transport and erythropoiesis in the mouse

Summary Removal of 15% of blood volume in the mouse increases erythropoiesis by a factor of 2.2 when measured 12 h after bleeding. Exposure of normal mice to 40% reduced barometric pressure for the same period of time increases erythropoiesis only by a factor of 1.6. The response to hypoxia takes place in the presence of a 40% reduction of oxygen consumption and tissue-venous P_{o 2}, changes which are concomitant with a 5-fold increase in plasma erythropoietin activity. The larger response in anemic animals on the other hand occurs without any detectable change in these parameters. These results cast serious doubts about the interpretation of the quantitative homeostatic control of erythropoiesis based solely on the action of erythropoietin.Acknowledgments. This work was supported by a grant from the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina. We thank Isabel Zingariello for excellent technical assistance.     

Effect of various stressors on the levels of lipid peroxide,antioxidants and Na+, K+-ATPase actrivity in rat brain

The level of malondialdehyde (MDA), an index of lipid peroxidation, and the antioxidants superoxide dismutase (SOD) and glutathione (GSH), as well as the activity of Na⁺, K⁺-ATPase, were assessed in whole rat brain after immobilization, anemic hypoxia (NaNO₂) and 72 h starvation. The effect of these stressors on plasma glucose and corticosterone levels was also observed. Hypoxia and starvation stimulated the lipidj peroxide formation in braini as indicated by an increase in the level of MDA, being higher after starvation than hypoxia. Brain SOD activity was also increased in response to hypoxia and starvation while GSH content was only diminished ini hypoxia. However, neither MDA nor antioxidants were affected by immobilization. On the other hand, the activity of brain Na⁺, K⁺-ATPase was significantly increased by immobilization and hypoxia but decreased in starvation. A similar pattern of change was also observed in plasma glucose and corticosterone levels in response to these stressors. These results elucidate differences in the biochemical response of animals towards various types of stress, with increased lipid peroxide formation in hypoxia and starvation.     

Apoptotic cell-derived factors induce arginase II expression in murine macrophages by activating ERK5/CREB

Apoptotic cell (AC)-derived factors alter the physiology of macrophages (MΦs) towards a regulatory phenotype, characterized by reduced nitric oxide (NO) production. Impaired NO formation in response to AC-conditioned medium (CM) was facilitated by arginase II (ARG II) expression, which competes with inducible NO synthase for l-arginine. Here we explored signaling pathways allowing CM to upregulate ARG II in RAW264.7 MΦs. Sphingosine-1-phosphate (S1P) was required and acted synergistically with a so far unidentified factor to elicit high ARG II expression. S1P activated S1P₂, since S1P₂ knockdown prevented ARG II upregulation. Furthermore, ERK5 knockdown attenuated CM-mediated ARG II protein induction. CREB was implicated as shown by EMSA analysis and decoy-oligonucleotides scavenging CREB in RAW264.7 MΦs, which blocked ARG II expression. We conclude that AC-derived S1P binds to S1P₂ and acts synergistically with other factors to activate ERK5 and concomitantly CREB. This signaling cascade shapes an anti-inflammatory MΦ phenotype by ARG II induction.