Acrylamide; induction of DNA damage, chromosomal aberrations and cell transformation without gene mutations

The genotoxic potential of acrylamide monomer (AA), a compound familiar as a raw material of polyacrylamide electrophoresis gel, was extensively investigated in vitro. The results were clear cut: AA did not induce any gene mutations in Salmonella/microsome test systems (TA98, TA100, TA1535, TA1537), Escherichia coli/microsome assay (WP2 uvrA-) up to a dose of 50 mg AA/plate, or in HPRT-locus in Chinese hamster V79H3 cells (AA, 1-7 mM, 24 h treatment). On the other hand, AA showed a strong positive response: (a) in a Bacillus subtilis spore-rec assay (DNA damage) at 10-50 mg/disc, (b) to a chromosomal structural change test (AA, 2-5 mM, 24 h treatment), (c) to a polyploidy test (AA, 1-5 mM, 24 h treatment) in Chinese hamster V79H3 cells, (d) to a cell transformation assay in mouse BALB/c3T3 cells (AA, 1-2 mM, 72 h treatment). Sister chromatid exchange was also weakly but significantly induced by AA (AA, 1-2.5 mM, 24 h treatment) in Chinese hamster V79H3 cells. Carcinogenic potential of AA was reported in mice and rats several years ago. AA thus seems to be a typical clastogenic rodent carcinogen without any gene mutation potential. Furthermore, this experiment showed for the first time positive response of AA to a microbial test system (B. subtilis spore-rec assay).

Aging retards spin clearance from mouse brain and food restriction prevents its age-dependent retardation

After the nitroxyl radical 3-carbamoyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl (carbamoylPROXYL) was intraperitoneally administered to mice, the time courses of changes in the intensity of signals in L-band electron spin resonance spectra from their brains were measured. The spin clearance rate of old, ad libitum-fed mice was lower than that of young, ad libitum-fed mice. The rate of old, food-restricted mice was significantly higher than that of old, ad libitum-fed mice and was comparable to that of young, ad libitum-fed mice. The spin clearance was found to be due to the one-electron reduction of the nitroxyl radical, because a decreased spin intensity of it in serum was restored to the original level by potassium hexacyanoferrate (III) oxidation in vitro. These results suggest that reducing capacity in the cardiovascular system of mice is decreased with advancing age, and that food restriction prevents an age-dependent decrease in the reducing capacity.

Antioxidant activity of nitroxide radicals in lipid peroxidation of rat liver microsomes

Inhibition of lipid peroxidation by nitroxide radicals in rat liver microsomes was studied using several nitroxide compounds which have various lipophilicities. Addition of NADPH to microsomes in an oxygen atmosphere induced lipid peroxidation as indicated by the increase of thiobarbituric acid (TBA)-reactive substances, hydroperoxide, conjugated diene, and oxygen consumption. Lipid peroxidation was inhibited by nitroxides located in both water phase and membrane. Oxygen consumption and the generation of active oxygens were inhibited by water-soluble nitroxides but not by intramembranous ones. Intramembranous nitroxides significantly prevented the production of conjugated dienes and lipid hydroperoxides. The facts suggest that water-soluble nitroxides interfere with the generation of active oxygens as preventive antioxidants, while intramembranous nitroxides inhibit the formation of lipid alkyl radical as chain-breaking antioxidants. The intensity of ESR signals due to intramembranous nitroxide radicals remained constant during the inhibition reaction of lipid peroxidation, suggesting that the prevention of lipid peroxidation is coupled with the reversible redox reaction between nitroxides and the reduced nitroxides in microsomes. The reduced forms of nitroxides, which were prepared by the reduction of intramembranous nitroxides, also inhibited the generation of TBA-reactive substances as well as the parent nitroxide. These facts indicate that either intramembranous nitroxide radicals or their reduced forms, "hydroxylamines," may be useful lipophilic antioxidants.

Whole mouse measurement of paramagnetism-loss of nitroxide free radical in lung with a L-band ESR spectrometer

Paramagnetism-loss of nitroxide radical in lung of whole mouse was characterized using L-band ESR technique. The nitroxide, hydroxy-TEMPO, which had been injected trans-tracheally into mouse lung was confirmed to lose its paramagnetism in one electron reduction. The reduction activity remained even after lavage of lung. The reduction was inhibited by N-ethylmaleimide, a membrane-permeable sulfhydryl-blocker, though direct reduction of the radical by sulfhydryls was not observed in vitro. Sulfhydryl-blockers floating in membranes also inhibited the reduction, depending on their chain length. The results indicate that the reduction may be done within plasma membranes of alveolar epithelial cells.

Occurrence and characteristics of hypodense eosinophils in rats infected with Trichinella spiralis

Hypodense eosinophils are observed in peripheral blood and tissue from patients with eosinophilia due to helminthic infections. In this study, the variation in eosinophil density was examined in rats during Trichinella spiralis infection. Hypodense eosinophils were observed in the peripheral blood in association with Trichinella infection. In peritoneal fluid, which was representative of tissue fluid, a majority of eosinophils were hypodense regardless of the infection. During the course of tissue eosinophilia after the infection, there was a particular increase in the lowest dense cells in the population of hypodense eosinophils. Eosinophils with lower density, demonstrated larger diameters and had more potent cytotoxic activity.

Effects of inspired oxygen concentration on in vivo redox reaction of nitroxide radicals in whole mice

Effects of inspired oxygen concentration on metabolism of nitroxide radical were measured in whole mice by using in vivo ESR. Oxygen concentration influenced spin-clearance of nitroxide differently in abdomen and head, suggesting that either O2 concentrations or metabolic mechanisms of nitroxide in the two domains were different.

Effects of the stereochemical orientation of phenethylamines and imidazolines on alpha-adrenergic receptor-mediated DNA synthesis in primary cultured rat hepatocytes

The hepatic alpha 1-adrenergic receptor mediates a variety of hepatic functions including respiration, glycogenolysis, gluconeogenesis, and growth. We have utilized a rat primary hepatocyte culture system to show that the alpha 1-adrenergic receptor can be activated in a stereoselective manner by a series of phenethylamines and catecholimidazolines resulting in the stimulation of DNA synthesis as determined by [3H]thymidine incorporation. The phenethylamines adhered to the Easson-Stedman hypothesis with a rank order of potency of (-)-(R)-norepinephrine (NE) greater than (+)-(S)-NE greater than the desoxy analog dopamine (DA) for the stimulation of DNA synthesis. However, the 2-substituted catecholimidazolines did not follow this trend and demonstrated an order of potency of the desoxy analog 3,4-dihydroxybenzyl imidazoline (DHT) greater than or equal to (-)-(R)-2-(3,4,alpha-trihydroxybenzyl)imidazoline (TBI) greater than (+)-(S)-TBI. 4-Substituted catecholimidazolines were less potent as inducers of DNA synthesis than the corresponding 2-substituted analogs with an order of potency of (+)-(R)-4-(3,4-dihydroxybenzyl)imidazoline (DBI) greater than (+,-)-(R,S)-DBI greater than (-)-(S)-DBI. When the beta-hydroxyl moiety of NE is replaced with an amino group as in 3,4-dihydroxyphenylethylenediamine, the isomers are less active than the beta-hydroxylated analogs and also demonstrate no stereoselectivity for the stimulation of DNA synthesis. These results demonstrate that the hepatic alpha 1-adrenergic receptor can recognize various isomeric forms of these compounds and that hepatocellular growth can be modulated in a stereoselective manner by phenethylamines and imidazolines.

Structure-activity studies of new imidazolines on adrenoceptors of rat aorta and human platelets

Potencies of new aromatic substituted fluoro or iodo analogues of catecholimidazolines on functional responses in rat aorta (alpha 1) and platelets (alpha 2) were quantified. (1) When compared either on the basis of EC50 or the dissociation constant (KA), 5-fluorocatecholimidazoline was as potent as the reference alpha 1-adrenoceptor agonist, phenylephrine in the vascular tissue. The maximum contraction of aorta produced by the fluoro analogue was, however, 17% higher than that of phenylephrine. The time required for 1/2 relaxation of the tissue after 5-fluoro hydroxy imidazoline was at least twice as long as that of the phenylephrine. The catechol moiety as well as fluorine substitution at the critical 5-position of the aromatic ring is essential for higher alpha 1 adrenoceptor-mediated potency. (2) As compared to the fluoro analogues, the adrenoceptor-mediated potencies of iodo-analogues were relatively weak on vascular tissue. Naphazoline and its analogues were partial agonists on vascular tissue with dissociation constants which ranged from 110 to 2600 nmol/l. (3) Imidazole analogues were generally less potent agonist than the imidazolines by one order of magnitude. (4) The vacular effects of all agonists were competitively blocked by prazosin with KB values which ranged from 0.04 to 0.48 nmol/l. Since the variation in KB values were within normal limits, the action of new imidazolines on rat aorta appears to be mediated mainly by the activation of the alpha 1-adrenoceptor. Prazosin 10 nmol/l abolished the vascular response of some partial agonists. This indicates a slightly different mode of interaction of agonists with the transduction process. (5) Carbon 4-substituted imidazolines produced little or no alpha 1 adrenoceptor-mediated intrinsic activity, but competitive receptor blocking potency was comparable to that of phentolamine. (6) Medetomidine was a partial agonist on the rat aorta with a KA of 260 nmol/l. When investigated as a blocker, the KB of medetomidine against phenylephrine was approximately 5600 nmol/l. The variation in the latter value was high. (7) In acetylsalicylic acid-treated human platelets, the alpha 2-adrenoceptor-mediated aggregatory effect of all fluoro analogues was weak. Iodo or naphazoline analogues did not initiate platelet aggregation but blocked the aggregation induced by epinephrine. The affinity of naphazoline for the alpha 2-adrenoceptor was 1100 nmol/l. The IC50 of medetomidine for platelet anti-aggregatory effect was 3300 nmol/l, which compares favorably with other imidazoline type of blockers of platelet aggregation. (8) Sympathomimetic vasoconstrictor actions and platelet aggregation effects of these compounds can be dissociated.(ABSTRACT TRUNCATED AT 400 WORDS)

Diversity of the pharmacological actions of some tolazoline analogues in human platelets and rat aorta

Tolazoline and two 4'-substituted benzyl analogues, 2-(4'-aminobenzyl) imidazoline (ABI) and 2-(4'-isothiocyanatobenzyl)imidazoline (IBI) were synthesized and evaluated for adrenoceptor activity in human platelets (alpha 2) and rat aorta (alpha 1), respectively. IBI was prepared as an affinity label for alpha-adrenoceptors and compared with chloroethylclonidine. Tolazoline, IBI, ABI and chloroethylclonidine inhibited the primary and secondary waves of epinephrine-induced human platelet aggregation. In aspirin treated platelets, primary wave aggregatory responses to epinephrine were blocked in a competitive manner by tolazoline, ABI. IBI and chloroethylclonidine giving pA2 values of 6.33, 6.12, 4.71 and 5.70, respectively. Only IBI blocked the aggregation responses to ADP (secondary wave only) arachidonic acid and U46619 (a thromboxane A2 agonist). Arachidonic acid-induced serotonin release and malondialdehyde formation and thrombin-induced release of [3H]arachidonic acid from membrane phospholipids were also blocked by IBI. These data indicate that IBI blocks arachidonic acid release, prostaglandin biosynthesis and the action of thromboxane A2. One hour exposure of aspirin treated platelets with IBI abolished inhibitory effects against epinephrine induced aggregation. In contrast to human platelets, both ABI and IBI produced contractions of rat aorta; however, only the responses to ABI were blocked in a competitive manner by the alpha-antagonists, phentolamine, prazosin, and SKF 104078. Moreover, idazoxan blocked the stimulatory actions of IBI, cirazoline and phenylephrine on rat aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

ESR measurement of radical clearance in lung of whole mouse

Clearance of the nitroxide radicals, hydroxy-TEMPO and carboxy-PROXYL, in whole-mouse lung was directly measured by in vivo ESR. After injecting a nitroxide radical, distribution of the nitroxide radical all over the lung was confirmed by ESR imaging. The ESR signal of hydroxy-TEMPO was reduced in the lung and the clearance obeyed first-order kinetics, whereas the signal of carboxy-PROXYL remained constant. Comparison of the clearance rates of live and dead mice indicated the presence of 2 different clearance systems in the lung: loss of its paramagnetism in the lung, and transfer from alveolar to the blood circulation system.

In vivo ESR measurement of free radicals in whole mice

The in vivo measurement of nitroxide radicals in whole mouse was carried out by L-band ESR spectroscopy. Spectra were successively observed in hepatic and bladder domains of female mice after intravenous administration of spin-labeled compounds (CPROXYL or TEMPOL). The signal intensities from both domains decreased gradually. The kinetic constants of clearance in the hepatic domain were 0.09/min for CPROXYL and 0.71/min for TEMPOL. The clearance constants in the bladder domain coincided with those in the hepatic domain within experimental error, whereas the constants in collected blood were 1/7-1/10 of those in the hepatic or bladder domains. The mechanism of clearance of nitroxide radicals in whole mice is discussed.

Effects of oxygen on the membrane structure and the metabolism of lipophilic nitroxide in rat liver microsomes

The effects of oxygen on the metabolism of lipophilic nitroxide and the membrane structure of microsomes were investigated with an ESR spectrometer equipped with a hand-made gas-permeable sampling tube. The half life of gas change in the membrane was confirmed to be 48 s by the line-width of the ESR signal. The signal intensity of lipophilic nitroxide in microsomal membranes decreased with NADPH under N2 and increased under O2. The change of signal intensity was reversible, suggesting that lipophilic nitroxide can be used as an indicator of the redox state in membranes for in vivo ESR imaging.

Synthesis and alpha 2-adrenoceptor effects of substituted catecholimidazoline and catecholimidazole analogues in human platelets

It is known that the steric requirements for the interactions of catecholamines and catecholimidazolines with alpha 1- and alpha 2-adrenoceptors are different. New analogues of desoxycatecholimidazoline (1), desoxycatecholimidazole (3), benzylic hydroxyl substituted imidazole (4), and the aromatic fluorine substitution analogues of 1 at the 2 (5), 5 (6), and 6 (7) positions, and a set of asymmetric 4-substituted catecholimidazolines, S-8 and R-8, were prepared and tested for interaction with alpha 2-adrenoceptors in human platelets. With the exception of 3, all compounds were selective for alpha-adrenoceptor-mediated responses in human platelets. Introduction of a double bond in imidazoline 1 to give an imidazole 3 or the introduction of a benzylic hydroxyl group to 3, as in 4, reduced the inhibition of platelet aggregation with a rank order potency of 1 greater than 3 greater than 4. Fluorine atom substitution at the 2-, 5-, or 6-positions only slightly modified the inhibitory activity of 1. Each analogue (1, 3-7) produced alpha 2-mediated inhibition of platelet adenylate cyclase and can be classified as a partial agonist. The inhibition potency of S-8 and R-8 against epinephrine-induced aggregatory responses were greatly different, and only R-8 and 4 were alpha 2-agonists on human platelet function. Our studies provide further evidence for the differential interaction of catecholamines and catecholimidazolines in alpha 1- and alpha 2-adrenoceptor systems.

Enhancing effect of C1q on IgG monoclonal antibody binding to hapten

We have previously demonstrated that IgG antibody binding to microfilariae of Dirofilaria immitis increased in the presence of purified C1q. The present study was designed to examine the mechanism of the C1q effect using a system with an antihapten monoclonal antibody (MoAb) and a hapten as an antigen. Microtiter plates were coated with 4-hydroxy-3-nitrophenyl-acetyl (NP)-bovine serum albumin (BSA), and mouse anti-NP MoAb (IgG) was added in the presence of C1q. The amount of IgG which bound to NP-BSA increased with the addition of C1q (p less than 0.01) when the antibody had both specificity to the antigen and ability to fix C1q. The C1q effect, examined using two anti-NP MoAbs with different affinities, was more apparent with the low-affinity antibody (LAMoAb) than with the high-affinity (HAMoAb; percent enhancement of IgG binding was 19 vs. 12%). The C1q effect on LAMoAb binding was doubled when a small amount of HAMoAb was incubated with LAMoAb. The C1q effect on IgG binding might be operative in the early phase of infection, where a small amount of high-affinity antibody and a relatively large amount of low-affinity antibody are produced in the host.

Alpha-tocopherol-induced hexagonal HII phase formation in egg yolk phosphatidylcholine membranes

The effect of alpha-tocopherol and its acetate on the membrane structure of egg yolk phosphatidylcholine (egg PC) dispersions was investigated using phosphate-31 nuclear magnetic resonance (31P-NMR) and small-angle X-ray diffraction. The incorporation of alpha-tocopherol into egg PC dispersions induced a change in the 31P-NMR spectrum from a multilamellar bilayer line shape to a hexagonal HII one. The phase transition by alpha-tocopherol was also confirmed by small-angle X-ray diffraction analysis. The amount of hexagonal HII phase increased with increase in concentration of alpha-tocopherol. Egg PC dispersions containing a molar ratio of 0.8 of alpha-tocopherol gave a 31P-NMR spectrum of an approximately hexagonal HII type at 37 degrees C. The amount of hexagonal HII phase increased with increasing temperature, indicating that the alpha-tocopherol-induced phase transition is thermotropic and that the transition temperature of egg PC membranes from the lamellar to the hexagonal HII phase is lowered by alpha-tocopherol. The incorporation of alpha-tocopherol acetate did not induce any phase transition. This fact indicates that the hydroxyl group of alpha-tocopherol may play an important role in the hexagonal HII phase formation of egg PC dispersions.

Amino acid sequence of monkey erythrocyte glycophorin MK. Its amino acid sequence has a striking homology with that of human glycophorin A

A major sialoglycoprotein, glycophorin MK, was isolated from monkey erythrocyte membranes by extraction with lithium diiodosalicylate and partition in aqueous phenol. Chemical analysis of glycophorin MK revealed that the glycophorin consists of 51% protein and 49% carbohydrate by weight, and contains no N-glycosidic oligosaccharide units. Only N-glycolylneuraminic acid (Neu5Gc) was detected as sialic acid. The amino acid sequence of glycophorin MK was determined, which demonstrated that the glycophorin consists of 144 amino acid residues and 18 oligosaccharide units linked O-glycosidically to the peptide backbone through serine or threonine residues. The molecular weight was estimated to be about 35,000 based on the amino acid residues and carbohydrate content. By comparison of the amino acid sequence with those of human, equine and porcine glycophorins, a striking sequence homology was observed between monkey and human glycophorin. Glycophorin MK demonstrated both M and N blood group activities.

ESR study on synthetic glyceroglycolipid liposomal membranes

We previously reported that glyceroglycolipid liposomes without cholesterol activated mouse peritoneal macrophages in vivo and in vitro, whereas glyceroglycolipid liposomes containing equimolar cholesterol did not. In order to characterize the properties of the glyceroglycolipid membranes, ESR spectroscopic studies were carried out with an acyl spin-labeled galactosyl ceramide (SL-GC) or a headgroup spin-labeled phospholipid (SL-6-DPPA) in 1,2-dipalmitoyl[beta-cellobiosyl-(1'---3)]glycerol (Cel-DAG) liposomal membranes. The ESR spectrum of the SL-GC in the Cel-DAG liposomes at 37 degrees C was a single broad line, indicating that the SL-GC molecules were excluded almost completely from Cel-DAG domains and formed clusters in the membranes. The spectrum of SL-6-DPPA in the Cel-DAG liposomes at 37 degrees C showed broad resonance lines with the central peak being the highest, while that at 60 degrees gave narrow lines with the low-field peak being the highest. This observation and rotational correlation time analysis showed that the molecular motions of spin-label moiety of the SL-6-DPPA were extremely restricted at 37 degrees C but not above Tc. These results suggest that below Tc the Cel-DAG molecules are packed tightly and restricted in motion in the membrane. Incorporation of cholesterol into the Cel-DAG liposomal membranes gave (1) the spectra of the SL-GC triplet, and (2) the spectra of the SL-6-DPPA narrow resonance with the low-field peak being the highest. These results suggest that cholesterol disturbs the rigid-packed structure of the Cel-DAG membrane and increases the molecular motions of the Cel-DAG. The DSC analysis of Cel-DAG with and without cholesterol agreed well to the results of the ESR technique. Thus we assume that peritoneal macrophages recognize the rigid-packed carbohydrate residues which are restricted in motion on the Cel-DAG membranes.

Effect of host lattice on antigenicity of glycophorin in membranes

The influence of the host lattice on the antigenicity of glycophorin in membranes was confirmed by complement-dependent immune lysis of liposomes with two rabbit antisera, which were prepared by immunization with either human red blood cells or isolated glycophorin A. The immune lysis by either antiserum depended on the kind of phospholipid in the liposomes. Anti-glycophorin antiserum more strongly recognized glycophorin in egg-lecithin membranes than in dipalmitoyl-lecithin membranes, as did anti-red blood cell antiserum. Cholesterol in the liposomal membranes influenced the antigenicity of glycophorin. The relationship between the state of glycophorin in membranes and recognition by antibody is discussed.

The immunopotentiating property of lipophilic muramyl dipeptide and its molecular state in liposomal membranes: plaque-forming cell responses and ESR studies

The immunopotentiating property of spin-labeled lipophilic muramyl dipeptide (SL-MDP) in liposomes was studied as to the plaque-forming cell (PFC) response to glycophorin, as an antigen, in membranes. The effect of SL-MDP depended on the densities of both SL-MDP itself and the antigen. The addition of the optimal amount of SL-MDP to liposomes containing a low density (0.016 mol%) of the antigen increased the PFC response by three times, whereas the presence of SL-MDP in optimal antigen density (0.032 0.127 mol%) membranes was rather inhibitory. In these liposomes, the amounts and molecular states of SL-MDP were determined from ESR spectra and are discussed in connection with its immunopotentiating property.

The evaluation of systolic time intervals and impedance cardiogram of neonates

The left ventricular systolic time intervals (STI) and impedance cardiogram were studied in 295 newborn infants. The wave pattern of the carotid was mainly anacrotic, similar to the wave pattern of hypertensive adult patients. In the neonatal period Q-I and Q-II intervals were gradually shortened and the prolongation of the preejection period (PEP), isometric contraction time (ICT) and an increase in PEP/ET were most prominent in the group at 24-72 hours after birth. The impedance cardiogram was able to be recorded clearly in newborn infants by the 4 electrode method. Stroke volume and cardiac output calculated from Kubicek's formula were most decreased in the group at 5-6 hours after birth. The estimated values were 3.79 +/- 0.78 ml and 456.2 +/- 92.2 ml/min. respectively at that stage, and gradually increased thereafter. In the babies in which the umbilical cord was clamped and tied later than 3 minutes after delivery, prolongation of the Q-I, Q-II intervals, pulse propagation time, PEP, ICT and a decrease in ET/PEP were remarkable, and cardiac output and blood pressure were relatively increased until about 120 hours after birth. These STI measurement and impedance cardiograms were useful to use in observing various cardiovascular changes in newborn infants. It was clear that the timing of clamping of the umbilical cord after delivery affected the cardiovascular hemodynamics of neonates.

Effect of aromatic fluorine substitution on the alpha and beta adrenoceptor-mediated effects of 3,4-dihydroxytolazoline in the pithed rat

The alpha and beta adrenoceptor-mediated effects of the catecholimidazoline, 3,4-dihydroxytolazoline, and its 2-, 5- and 6-aromatic fluorine-substituted derivatives have been studied in the cardiovascular system of the pithed rat. All four compounds produced vasopressor responses in beta adrenoceptor blocked (propranolol, 3 mg/kg i.v.) animals. The pressor responses produced by all four compounds were antagonized by the selective alpha-1 adrenoceptor antagonist, prazosin (0.1 mg/kg i.v.), and were relatively unaffected by the selective alpha-2 adrenoceptor antagonist, rauwolscine (0.5 mg/kg i.v.), indicating that vasoconstriction produced by the fluorinated imidazolines was mediated exclusively by postjunctional vascular alpha-1 adrenoceptors. The rank order of potency at the alpha-1 adrenoceptor was: 5-fluoro greater than 2-fluoro greater than desfluoro greater than 6-fluoro. At higher doses, 3,4-dihydroxytolazoline and its fluorinated derivatives produced an alpha-2 adrenoceptor-mediated inhibition of neurogenic tachycardia in animals pretreated with prazosin, with all four compounds being equipotent. In rats with complete alpha adrenoceptor blockade [phenoxybenzamine (3 mg/kg i.v.), prazosin (0.1 mg/kg i.v.) and rauwolscine (1 mg/kg i.v.)] whose blood pressure was elevated by constant infusion of angiotensin II (150 ng/kg/min i.v.), high doses of the 2-fluoro-, but not the 5-, 6- or desfluoro catecholimidazoline derivatives, produced a beta-2 adrenoceptor-mediated vasodepressor response. All four compounds produced a beta-1 adrenoceptor-mediated positive chronotropic response in pithed rats with the rank order of potency being: 2-fluoro = 5-fluoro greater than desfluoro greater than 6-fluoro.(ABSTRACT TRUNCATED AT 250 WORDS)

Localization of the active center of nitroxide radical reduction in rat liver microsomes: its relation to cytochrome P-450 and membrane fluidity

The properties and localization of the active center of NADPH-dependent nitroxide radical reduction in rat liver microsomes were investigated with the following five spin-probes as substrates; tetramethylpiperidinol-N-oxyl (TEMPOL) and four spin-labeled stearic acid derivatives with a nitroxide radical at the 5th, 7th, 12th, or 16th position of the hydrocarbon chain (abbreviated as 5SLS, 7SLS, 12SLS, and 16SLS, respectively). The ESR signals of these spin-probes in microsomes decreased on the addition of NADPH, and the decay was inhibited by pretreatment with SKF-525A. Experiments with various microsomal preparations induced by phenobarbital (PB), polychlorinated biphenyls (PCB), or 3-methylcholanthrene (3-MC) revealed that the reduction rate was correlated to the concentration of cytochrome P-450 but not to that of NADPH reductase. Thus, the nitroxide radicals of the SLSs and TEMPOL seem to be reduced by the combined action of NADPH-cytochrome P-450 reductase and cytochrome P-450. The decay showed a lag time, but no distinct correlation was observed between the lag time and the spin-probe species. On the other hand, the initial velocity of the nitroxide reduction depended strongly on the spin-probe species. Among the five spin-probes, 7SLS was reduced most quickly, followed by 5SLS, 12SLS, TEMPOL, and 16SLS in that order. The reduction rate varied from 0.18/min for 7SLS to 0.08/min for 16SLS. There was a linear relation between the cytochrome P-450 content and the reduction rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Fc-epsilon-receptor-bearing lymphocytes in patients with clonorchiasis

Expression of Fc-epsilon-receptors (Fc epsilon R) on peripheral blood lymphocytes was examined in patients with clonorchiasis. Mean serum IgE levels in these patients was 2,518 IU/ml. Fc epsilon R was detected by flow cytometry analysis with monoclonal antibody. The frequency of Fc epsilon R+ lymphocytes and the density of Fc epsilon R on the cells in the patients were similar to those in normal subjects. Most of the Fc epsilon R+ lymphocytes were B cells. The number of Fc epsilon R+ cells decreased after incubation in serum-free medium at 37 degrees C for 3 h. The amount of regulatory molecules of IgE production, IgE binding factor, was not significantly different between the patients and normal subjects. The number of Fc gamma R bearing T or B cells in the patients was also similar to that of normal subjects. These results indicate that the mechanisms of elevated serum IgE in patients with clonorchiasis might be different from other diseases with hyperglobulinemia E.

Structure of the major O-glycosidic oligosaccharide of monkey erythrocyte glycophorin

Sialic acids and the major O-glycosidic oligosaccharide of glycophorin MK from monkey (Japanese monkey, Macaca fuscata) erythrocyte membranes were characterized. N-Glycolylneuraminic acid (Neu5Gc) was found as the major sialic acid, which was confirmed by gas-liquid chromatography-mass spectrometry as the trimethylsilyl methyl ester. Three O-glycosidic oligosaccharide units were obtained from a tryptic glycopeptide that contained all of the carbohydrate units in glycophorin MK by mild alkaline borohydride/borotritide treatment. Carbohydrate analyses of the oligosaccharides revealed that they were composed of Neu5Gc, galactose and N-acetylgalactosaminitol in the molar ratios of 1:1:1 (trisaccharide), 2:1:1 (tetrasaccharide) and 3:1:1 (pentasaccharide). The content of oligosaccharide units was estimated to be 1:12:5 for penta-, tetra- and trisaccharide, respectively, based on the yields, the molecular weight, and the number of oligosaccharide attachment sites in the amino-acid sequence. The tetrasaccharide was the major oligosaccharide and its structure was proposed to be Neu5Gc alpha 2-3Gal beta 1-3[Neu5Gc alpha 2-6]GalNAcol.

Paradoxical effects of isothiocyanate analog of tolazoline on rat aorta and human platelets

The isothiocyanate analog (IBI) of tolazoline produced contraction of the rat aortic strip, with an ED50 value of 1.63 x 10(-5) M. The maximum contraction of the analog was nearly equal to that of tolazoline or phenylephrine. At 27 degrees C the tissue reactivity of phenylephrine and IBI was similar. When compared at equiactive concentrations, the total duration of contraction of IBI was three times longer than that of tolazoline. Thus, the longer duration of action of IBI may be attributed to the S=C=N group substitution of the molecule. IBI at 10(-6) M shifted the dose-response curve of phenylephrine to the right with reduction in maxima. Phentolamine and other alpha 1 or alpha 2 adrenoceptor blockers failed to block the responses of IBI in aorta, whereas verapamil or nifedipine blocked the response significantly. It appears that IBI is acting through calcium-channel-sensitive or calcium-receptor-related mechanism(s). In aspirin-treated platelets from human plasma, a distinct phase of aggregation induced by epinephrine can be blocked by IBI with KB of 2 x 10(-5) M. This indicates a small but selective alpha 2 related action of IBI. The aggregation induced by ADP or second component of aggregation induced by epinephrine were also blocked by IBI at concentrations comparable to that of the alpha 2-adrenoceptor-mediated response. This indicates a lack of specificity of IBI in differentiating various phases of aggregation. Therefore, as compared to tolazoline, IBI presents an interesting paradox in its interaction with various receptors or mechanisms in the vascular tissue and platelets.

Effects of benzylic hydroxyl substitution on the alpha-adrenoceptor blocking activity of tolazoline

The R(-)- and S(+)-enantiomers of alpha-hydroxytolazoline, the benzylic hydroxy-substituted derivative of the alpha-adrenoceptor antagonist, tolazoline, were evaluated at alpha 1- and alpha 2-adrenoceptors in canine saphenous vein. Benzylic hydroxyl substitution of tolazoline in either the R(-) or S(+) configuration significantly decreased affinity at both alpha 1- and alpha 2-adrenoceptors. Differences in affinity between the R(-)- and S(+)-enantiomers were small, which is characteristic of imidazolines, but in marked contrast to phenethylamines where enantiomeric differences are large. The rank order of affinities at alpha 1- and alpha 2-adrenoceptors is tolazoline greater than S(+)-alpha-hydroxytolazoline = R(-)-alpha-hydroxytolazoline, which is different from that order predicted by the Easson-Stedman hypothesis (i.e., R(-) greater than S(+) = desoxy). The findings support our contention that phenethylamines and imidazolines interact differently with alpha-adrenoceptors.

C1q enhancement of antibody-dependent granulocyte-mediated killing of nonphagocytosable targets in vitro

A possible role for C1q in antibody-dependent granulocyte-mediated killing of nonphagocytosable targets was investigated utilizing IgG-dependent granulocyte cytotoxicity directed against microfilariae of Dirofilaria immitis. Granulocyte-mediated killing of microfilariae is enhanced by addition of fresh serum. Lack of C4 did not significantly reduce the observed increase in cytotoxicity. The addition of highly purified monomeric human Clq (0.2 microgram/ml) in the presence of immune IgG resulted in a two- to fivefold enhancement of killing (P less than 0.025). C1q enhancement of killing occurred in the absence of fluid-phase IgG, but killing was significantly less than when both fluid-phase IgG and C1q were present. The effect of C1q was inhibited by the addition of solubilized type I collagen (44-92% inhibition of killing, P less than 0.05). Significant 125I-Clq binding to microfilariae occurred only in the presence of immune IgG. In addition, C1q in concentrations ranging from 0.5 to 2.0 micrograms/ml resulted in a dose-dependent increase in binding of 125I-immune IgG to microfilariae. Finally, when purified C1q was added to preopsonized, washed microfilariae, granulocyte production of superoxide was increased from 0.25 +/- 0.07 to 0.68 +/- 0.07 nm/10(6) cells.10 min (P less than 0.01). These results describe a novel functional role for C1q in enhancement of antibody-dependent cellular cytotoxicity towards nonphagocytosable targets.

Purification and some properties of NADPH-cytochrome P-450 reductase from crab-eating monkey liver microsomes

NADPH-cytochrome P-450 reductase was purified to 30.8 units/mg from monkey liver microsomes. The purified reductase showed one major protein band (78,000) and two minor ones (58,000 and 20,000) on analysis by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Monkey, rat, and guinea pig reductases were not immunochemically identical to each other judged from Ouchterlony double diffusion analysis and immunotitration with regard to NADPH-cytochrome c reductase activity.

Activation of alpha-1 adrenoreceptors of rat aorta by analogs of imidazoline

New analogs of desoxycatecholimidazoline were synthesized for elucidating the steric requirements for the activation of alpha-1 adrenoreceptors. The compounds tested on rat thoracic aorta in this study were: desoxycatecholimidazole with and without bridge carbon hydroxyl group, analogs of desoxycatecholamidazoline with fluorine substitution at position 2, 5 or 6 of the catechol ring and hydroxybenzyl group at carbon-4 of the imidazoline part of the molecule. The addition of a double bond in the imidazoline to give an imidazole results in a decrease in potency and the introduction of benzylic hydroxyl group also reduces its activity by 4- and 6-fold, respectively. 2-Fluoro and 5-fluoro catecholimidazoline possess full agonist activity; their potencies being even higher than the parent molecule. The 6-fluoro analog is a partial agonist inasmuch as it produces a response that is only 30% of the maximum response produced by other analogs of imidazoline. In the present study, 4-substituted imidazolines retain their agonist activity, although weaker than desoxycatecholimidazoline. The potency of R- and S-isomers of 4-substituted catecholbenzyl imidazoline were similar. Although these isomers exhibit apparent chemical similarity to catecholamines, small differences between the activity of stereoisomers indicate that the mode of interaction of these molecules at alpha adrenoreceptor may differ from that of stereoisomers of epinephrine.

Male hypogonadism as a candidate of deficiency of postnatal testicular growth or differentiating factor(s): a new autosomal recessive mutation in the rat

A new rat mutant showing severe male hypogonadism (hgn for the gene symbol) was found and isolated from the hereditary hydronephrosis rat strain originating from the Wistar-Imamichi rat. The affected rats have very tiny testes that weigh 26 mg in the adult, and contain small numbers of seminiferous tubules with degenerated Sertoli cells. It is difficult to identify the gonocyte in the seminiferous tubules in the mutant testis. Very small male accessory sex organs are all present in the mutant. The number of chromosomes is 42 (40A + XY). The structure of each chromosome is normal, showing that the mutant has male sex genes. Thus, it was considered that this status is not due to either lack of the H-Y antigen or Muellerian inhibiting factor or expression of the Tfm. By analyzing the pedigree of the matings producing the mutant, it was concluded that the status was expressed only in the male, but inherited with a single autosomal recessive trait with existence of the phenotypically normal fertile female recessive homozygote. A possible deficiency of certain known or unknown testicular growth or differentiating factor(s) in the mutant is suggested.

Alkali-labile oligosaccharide units of a sialoglycoprotein from rabbit erythrocyte membranes

Two glycoproteins (apparent molecular weights 120,000 and 70,000) were extracted from rabbit erythrocyte membranes, and only one (Mr 120,000), which is a sialoglycoprotein, contained O-glycosidically linked sugar chains. Alkali-labile oligosaccharide units of the sialoglycoprotein were released as reduced oligosaccharides by NaOH-NaB3H4 treatment, and then purified by gel filtration on a Bio-Gel P-4 column followed by ion-exchange chromatography. From the results of methylation analysis, mass spectrometry and chromium trioxide oxidation, the main oligosaccharide unit was determined to be a linear trisaccharide (85% by weight), NeuNGc alpha(2----3)Gal beta(1----3)GalNAcol. In addition, small amounts of a tetrasaccharide (11% by weight) and a disaccharide (4% by weight) were found, which were determined to have the following structures, NeuNGc alpha(2----3)Gal beta(1----3)[NeuNGc alpha(2----6)] GalNAcol and Gal-GalNAcol, respectively.

Antitumor activity of polysaccharide fractions from pine cone extract of Pinus parviflora Sieb. et Zucc

Hot water extract of pine cone (PCE) of Pinus parviflora Sieb. et Zucc. dose-dependently suppressed both solid and ascites tumor cells transplanted into various mice. Acidic polysaccharides of PCE significantly increased the survival time of mice bearing ascites tumor cells, and activity increased with acidity. One of the four polysaccharide fractions obtained by NaOH extraction showed the most potent antitumor activity. This fraction significantly suppressed the growth of solid tumor cells, with occasional tumor regression and necrosis, and with little or no cytocidal effect on cultured tumor cells. All acidic polysaccharides were able to activate mouse macrophage-like cell line J774.1. There did not appear to be any correlation between the antitumor activity of these polysaccharides and their content of arabinose (or fucose), mannose, galactose, glucose, or uronic acid.

Dimethylthetin can substitute for glycine betaine as an osmoprotectant molecule for Escherichia coli

Glycine betaine is believed to be the most active naturally occurring osmoprotectant molecule for Escherichia coli and other bacteria. It is a dipolar ion possessing a quaternary ammonimum group and a carboxylic acid group. To examine the molecular requirements for osmoprotective activity, dimethylthetin was compared with glycine betaine. Dimethylthetin is identical to glycine betaine except for substitution of dimethyl sulfonium for the quaternary nitrogen group. Dimethylthetin was found to be about equally as effective as glycine betaine in permitting E. coli to grow in hypertonic NaCl, and both compounds were recovered almost completely from bacterial cells grown in the presence of hypertonic NaCl. 3-Dimethylsulfonioproprionate, an analog of dimethylthetin observed in marine algae, and 3-Dimethylsulfonio-2-methylproprionate were found to be less active. Dimethylthetin may prove useful as a molecular probe to study betaine metabolism and as a model for the development of antibacterial agents.

Dimethylthetin can substitute for glycine betaine as an osmoprotectant molecule for Escherichia coli

Glycine betaine is believed to be the most active naturally occurring osmoprotectant molecule for Escherichia coli and other bacteria. It is a dipolar ion possessing a quaternary ammonimum group and a carboxylic acid group. To examine the molecular requirements for osmoprotective activity, dimethylthetin was compared with glycine betaine. Dimethylthetin is identical to glycine betaine except for substitution of dimethyl sulfonium for the quaternary nitrogen group. Dimethylthetin was found to be about equally as effective as glycine betaine in permitting E. coli to grow in hypertonic NaCl, and both compounds were recovered almost completely from bacterial cells grown in the presence of hypertonic NaCl. 3-Dimethylsulfonioproprionate, an analog of dimethylthetin observed in marine algae, and 3-Dimethylsulfonio-2-methylproprionate were found to be less active. Dimethylthetin may prove useful as a molecular probe to study betaine metabolism and as a model for the development of antibacterial agents.

Dynamic properties of the haptenic site of lipid haptens in phosphatidylcholine membranes. Their relation to the phase transition of the host lattice

The relation between the dynamic properties of the haptenic site of lipid haptens and the phase transition of the host lattice was investigated using head group spin-labeled phosphatidylethanolamines, that is, spin-label lipid haptens (Brûlet, P., and H. M. McConnell, 1976, Proc. Natl. Acad. Sci. USA., 73:2977-2981; Brûlet, P., and H. M. McConnell, 1977, Biochemistry, 16:1209-1217). The electron spin resonance (ESR) spectra of the lipid haptens in liposomal membranes showed three narrow resonance lines, whose widths and hyperfine splitting values suggested that the haptenic site, i.e., the spin-label moiety, should be exposed in the water phase. The line width of each peak depended on the host lipid species and on the incubation temperature. A temperature study using dipalmitoylphosphatidylcholine (DPPC) liposomes showed that the dynamic properties of the haptenic site were related to the main phase transition and the subphase transition of the host lattice but not to the prephase transition. The angular amplitudes of the tumbling motion of the haptenic site were estimated using oriented multibilayer systems. The angular amplitude of dipalmitoyl-phosphatidyl-N-[[N-(1-oxyl-2,2,6, 6-tetramethyl-4-piperidinyl)-carbamoyl]-methyl]-ethanolamine in DPPC membranes was 63 degrees at 2 degrees C, and it increased slightly with an increase in temperature regardless of the phase transition of the host lattice. The value for egg phosphatidylcholine (PC) at 25 degrees C was the same as for DPPC above its main phase transition temperature. Rotational correlation time analysis showed that the axial rotation of the haptenic site was preferable to the tumbling motion of the rotational axis, and the predominance depended on the phase transition, Lc----L beta' and P beta'----L alpha. Elongation of the spacer arm between the haptenic site and phosphate increased the angular amplitude of the tumbling motion but reduced the effect of the host lattice. Spin-label lipid haptens with unsaturated fatty acyl chains were distributed heterogeneously in DPPC membranes, whereas those with the same fatty acyl chain as the host lattice were distributed randomly. The ESR spectrum of a lipid hapten under its prephase transition temperature showed two components, broad and narrow. This suggests that at least two different domains, a hapten-rich domain and a hapten-poor one, may coexist in membranes. ESR measurements at various temperatures suggested that the haptenic site fraction in the hapten-rich domain decreased in part during the phase transition from L beta' to P beta', and disappeared completely in the La phase. The spatial mobility and lateral diffusion of lipid haptens will be discussed in greater detail.

A rare case of Maffucci's syndrome combined with tuberculum sellae enchondroma, pituitary adenoma and thyroid adenoma

Maffucci's syndrome is a rare, congenital mesodermal dysplasia combined with dyschondroplasia and haemangiomatosis, and there are only about 150 reported cases. This syndrome is often combined with other neoplasms. Our case was associated with goitre, enchondroma of the tuberculum sellae and pituitary adenoma; the latter brought about disturbance of vision. Including ours, four cases of Maffucci's syndrome associated with pituitary adenoma are found in the literature. In the case of Maffucci's syndrome, it is necessary to examine associated disease as well as associated pituitary adenoma and skull base enchondroma, similar to the correlation of von Recklinghausen's disease with acoustic neurinoma.

Asymmetric catecholimidazolines and catecholamidines: affinity and efficacy relationships at the alpha adrenoreceptor in rat aorta

The epinephrine (EPI) stereoisomers interact with the alpha adrenoreceptor according to the Easson-Stedman model with an order of potency of (-)-EPI greater than (+)-EPI = Epinine. A series of catecholimidazolines (CI) and catecholamidines (CA) were compared with the EPI series for the relationship of stereoisomerism to potency, affinity and efficacy. Within each group of desoxy compound and stereoisomers obtained by -OH substitution at the benzylic position, differences in potency were found to be due solely to differences in affinity; differences in efficacy were not significant. The stereoisomers of the CI and CA series followed the order of potency predicted by the Easson-Stedman model: (-)-isomer greater than (+)-isomer. The desoxy analogs, in contrast to the prediction based on the Easson-Stedman hypothesis, were equal (CI) or greater (CA) in potency than the more potent (-)-isomer of each series. Possible explanations for this include differences in physical properties in the desoxy analogs of CI and CA compared with the corresponding enantiomers. Methyl or benzyl substitution at C-4 of the imidazoline ring decreased potency over 100-fold; potency differences between enantiomers were negligible. Thus, the Easson-Stedman model cannot be extended to either the CI or CA series of alpha adrenoreceptor agonists.

Specific interaction of arabinose residue in ginsenoside with egg phosphatidylcholine vesicles

The interaction of the specific sugar residue in ginsenosides with egg phosphatidylcholine vesicles was investigated by ESR spectrometry using phosphatidic acid spin-labeled at the polar head groups. Ginsenoside-Rc, which has an alpha-L-arabinofuranose residue and agglutinability toward egg yolk phosphatidylcholine vesicles (Fukuda, K. et al. (1985) Biochim. Biophys. Acta 820, 199-206), caused the restriction of the segmental motion of spin-labeled phosphatidic acid in egg phosphatidylcholine vesicles, indicating that the saponin interacted with the polar head groups of vesicles. Other ginsenosides-Rb2, Rb1, Rd and p-nitrophenyl glycoside derivatives which have less or no agglutinability were also investigated in the same manner. Only ginsenoside-Rb2 and p-nitrophenyl alpha-L-arabinofuranoside which have the specific sugar residue (arabinose) showed a strong interaction with the polar head groups of vesicles. To gain an insight into the mechanism of agglutination by ginsenoside-Rc, the interaction with the fatty acyl groups was also studied by using phosphatidylcholine spin-labeled at the fatty acyl groups. Ginsenoside-Rc increased the order parameter of the spin-labeled phosphatidylcholine, indicating that the saponin was inserted into lipid bilayers. In other saponins investigated, only ginsenoside-Rb2 interacted with the fatty acyl part of vesicles. The process of expression of agglutination by ginsenoside-Rc was discussed on the basis of the ESR studies.

Interaction of enantiomers of hydroxy tolazoline with adrenoceptors

Adrenoceptor-mediated effects of the enantiomers of hydroxytolazoline and tolazoline (i.e., desoxy derivative) have been investigated in vitro. The enantiomers and tolazoline were partial agonists of postjunctional alpha 1-adrenoceptors in rat aorta. The rank order of potencies of the compounds in this system was as follows: tolazoline greater than R(-)-hydroxytolazoline greater than S(+)-hydroxytolazoline. The efficacy of R(-)-hydroxytolazoline was higher than that of tolazoline, though its affinity for the receptor was less. The KB values for prazosin against these agonists were nearly equal, which indicated that these imidazolines activate the same type of receptor in rat aorta. The S(+)-isomer, however, produced both a prazosin sensitive and resistant component of the response. The interactions of the derivatives with presynaptic alpha 2-adrenoceptors were studied in field-stimulated myenteric plexus-longitudinal muscle of guinea-pig ileum. These substances were blockers at presynaptic alpha 2-adrenoceptors. Based on KB values, the order of affinity in this system was as follows: tolazoline greater than S(+)-isomer greater than or equal to R(-)-isomer. beta-Adrenoceptor mediated activity was quantitated in guinea-pig and rat atria. R(-)-hydroxytolazoline lacked chronotropic effects either in guinea pig or rat atria. At 3 X 10(-4) M the isomer did not antagonize the effect of isoproterenol in the atria. On the other hand, S(+)-hydroxytolazoline produced a variable chronotropic effect in guinea-pig atria, but failed to show any significant activity in rat atria. Thus, the beta-adrenoceptor mediated action appears to be insignificant. Steric aspects of alpha-adrenoceptor mediated events are discussed.

Clq enhancement of IgG-dependent eosinophil-mediated killing of schistosomula in vitro

Antibody-dependent eosinophil-mediated cytotoxicity plays a role in host protection against metazoan parasite invasion. We examined a possible role for Clq in eosinophil-mediated cytotoxicity by using a Schistosoma mansoni schistosomula killing system in vitro. The addition of monomeric purified human Clq enhanced IgG-dependent human eosinophil-mediated killing from 1.4-fold to 2.3-fold (mean percent killing 12% +/- 4 vs 21% +/- 4, p less than 0.005) when the immune IgG concentration was low. In contrast, there was no significant enhancement of neutrophil-mediated killing. When the IgG concentration was increased fourfold Clq did not cause enhancement of eosinophil-mediated killing (35% +/- 9 vs 37% +/- 5). Preincubation of eosinophils with type 1 collagen abrogated Clq enhancement of killing, raising the possibility of a receptor-mediated process, which depends upon cellular binding of Clq via the collagenous portion of the molecule. Eosinophils and neutrophils were examined for the presence of Clq receptors by using 125I labeled Clq. Clq binding to both cell types was saturable, reversible, and specific, indicating that binding is through specific receptors. Type 1 collagen inhibited binding of Clq to cells, suggesting that Clq binding is via the collagenous stalk of Clq. The number of receptors was approximately twice as high for eosinophils as compared with neutrophils (1.9 X 10(7) vs 1.1 X 10(7), p less than 0.025). Affinity constants for the two cell types were similar (1.5 X 10(7) vs 1.3 X 10(7). These findings suggest that Clq and receptors for Clq on eosinophils may be important for eosinophil-mediated schistosomula killing.

Clq enhancement of IgG-dependent eosinophil-mediated killing of schistosomula in vitro

Antibody-dependent eosinophil-mediated cytotoxicity plays a role in host protection against metazoan parasite invasion. We examined a possible role for Clq in eosinophil-mediated cytotoxicity by using a Schistosoma mansoni schistosomula killing system in vitro. The addition of monomeric purified human Clq enhanced IgG-dependent human eosinophil-mediated killing from 1.4-fold to 2.3-fold (mean percent killing 12% +/- 4 vs 21% +/- 4, p less than 0.005) when the immune IgG concentration was low. In contrast, there was no significant enhancement of neutrophil-mediated killing. When the IgG concentration was increased fourfold Clq did not cause enhancement of eosinophil-mediated killing (35% +/- 9 vs 37% +/- 5). Preincubation of eosinophils with type 1 collagen abrogated Clq enhancement of killing, raising the possibility of a receptor-mediated process, which depends upon cellular binding of Clq via the collagenous portion of the molecule. Eosinophils and neutrophils were examined for the presence of Clq receptors by using 125I labeled Clq. Clq binding to both cell types was saturable, reversible, and specific, indicating that binding is through specific receptors. Type 1 collagen inhibited binding of Clq to cells, suggesting that Clq binding is via the collagenous stalk of Clq. The number of receptors was approximately twice as high for eosinophils as compared with neutrophils (1.9 X 10(7) vs 1.1 X 10(7), p less than 0.025). Affinity constants for the two cell types were similar (1.5 X 10(7) vs 1.3 X 10(7). These findings suggest that Clq and receptors for Clq on eosinophils may be important for eosinophil-mediated schistosomula killing.

Alpha-adrenoceptor-mediated actions of optical isomers and desoxy analogs of catecholimidazoline and norepinephrine in human platelets: in vitro

Adrenoceptor-mediated effects of the enantiomers of optically active imidazoline, 2-(3,4,alpha-trihydroxybenzyl imidazoline (catecholimidazoline; CI), and norepinephrine (NE), and the corresponding desoxy derivatives, 2-(3,4-dihydroxybenzyl)imidazoline (desoxy-CI) and dopamine, have been investigated in human platelets. Differences between responsiveness of platelets from donor to donor were observed in the presence of the isomers and the desoxy analogs of NE and CI. In certain platelet preparations, all compounds gave concentration-dependent stimulatory responses, whereas in other preparations, only R(-)-NE and R(-)-CI were inducers of platelet aggregation and serotonin release. The rank order of stimulatory potencies (EC50; microM) for CI and NE was R(-)-NE (1.3) greater than R(-)-CI (7.5) greater than S(+)-NE (19) = S(+)-CI (20) = dopamine (22) greater than desoxy-CI (greater than 35). Unlike R(-)-CI, both S(+)-CI and desoxy-CI were either agonists or antagonists of human platelet function. In preparations unresponsive to the S(+)-isomers or desoxy analogs, the potencies (EC50) for R(-)-NE and R(-)-CI were 1.7 and 7.7 microM respectively. The corresponding inactive CIs [S(+)-CI and desoxy-CI] were inhibitors of both primary and secondary phases of aggregation and serotonin release responses to R(-)-CI and R(-)-NE, respectively. In contrast, the aggregation responses to ADP, arachidonic acid or U46619 were not blocked by S(+)-CI or desoxy CI. The rank order of inhibitory potencies for selected alpha-adrenoceptor agents against R(-)-NE was phentolamine greater than clonidine greater than desoxy-CI greater than S(+)-CI. Moreover, the relative inhibitory potencies of phentolamine and desoxy-CI against aggregation responses to R(-)-NE and R(-)-CI, respectively, were the same. These results suggest that the enantiomers and desoxy derivatives of CI and NE mediate their effects in human platelets by an interaction with alpha-adrenoceptors; catecholamines and imidazolines interact with the same alpha-adrenoceptors in human platelets; the stereochemical requirements of both chemical classes for stimulatory activity in human platelets adhere to the Easson-Stedman hypothesis in this alpha 2-adrenoceptor system; and desoxy-CI possessed the highest potency as an antagonist of alpha-adrenoceptors which suggests that the hydroxy group at the benzylic carbon atom of these imidazolines may not be required for maximal binding to adrenoceptors in platelets.

Micellar formation of spin-labeled fatty acyl derivatives of lipophilic muramyl dipeptides and their incorporation into liposomal membranes

A lipophilic muramyl dipeptide (MDP) with a nitroxide moiety in its acyl chain (SL-MDP) and its N-methyl derivative (SL-methyl MDP) were synthesized. The SL-MDPs formed micelles (cmc, 0.1-0.3 mM). The ESR spectra of the SL-MDPs in phosphatidylcholine (PC) liposomes at 25 degrees C consisted of an anisotropic signal and three sharp lines, indicating that both SL-MDPs partitioned between membranes and aqueous phase. The amounts of the SL-MDPs in membranes depended on the phospholipid species and the cholesterol (Chol) content, but no appreciable difference was observed between SL-MDPs. The SL-MDPs partitioned well at 25 degrees C into egg yolk PC liposomes but not into pure dipalmitoylphosphatidylcholine (DPPC), suggesting that the incorporation may be related to the membrane fluidity. Chol enhanced the incorporation into both phospholipids. The mobilities of the SL-MDPs in the membranes were less than that of the corresponding spin-labeled fatty acid. Comparison of the mobilities among SL-MDPs, spin-labeled ganglioside and spin-labeled galactosylceramide showed that the hydrophilicity of the polar group may influence the immobilization of their acyl chains.

Human case of dracunculiasis in Japan

Dracunculus medinensis was recovered from a 42-year-old man residing in Shizuoka, Japan. Part of an adult female worm was removed from an abscess in the subcutaneous tissue on his right gastrocnemial muscle. The worm's morphology and that of the embryos found in its uterus revealed that the parasite was Dracunculus medinensis. This is the first human case of dracunculiasis acquired in Japan.