Effect of lipopolysaccharide on transport and metabolism of arginine in mouse peritoneal macrophages

The transport activity of arginine in mouse peritoneal macrophages was strongly induced when they were cultured with 1 ng/ml bacterial lipopolysaccharide (LPS) for 12 h. Arginine in the medium decreased whereas ornithine in the medium increased during the culture. This time-dependent change of arginine to ornithine was accelerated by LPS. However, the activity of arginase in the macrophages did not change during the culture with or without LPS and release of arginase from the cells to the medium was not detected. It is suggested that the transport of arginine and ornithine was a rate-limiting step in arginine-to-ornithine conversion in the macrophage culture medium. A possible role of the induction of arginine transport activity in the macrophage cytocidal activity due to arginine depletion and nitric oxide production is discussed.

Analysis of swinepox virus antigens using monoclonal antibodies

Seventeen monoclonal antibodies (MAbs) against swinepox virus (SPV) were produced and characterized. These MAbs were classified into eight groups (A through H) on the basis of the molecular weight of the polypeptides which they recognized and the staining patterns of antigens in SPV-infected cells by the indirect immunofluorescent (IF) technique. The MAbs belonging to groups A, B, C and G recognized late antigens in cytoplasmic inclusion bodies with molecular weights of 97 kD, 65 kD, 48 kD and 15 kD, respectively. The MAbs belonging to groups D and H respectively recognized 35 kD and 12 kD late antigens, which first appeared in cytoplasmic inclusion bodies and spread to the cytoplasms and surface membranes of the infected cells. The MAb of group F recognized an 18 kD late antigen with granular distribution in the cytoplasm. The MAbs of group E recognized a 32 kD early antigen. Although all the MAbs belonging to the six groups (A, D through H) were specific for SPV, some of those belonging to groups B and C showed cross-reactivity with members of the other genera of poxviridae. An MAb in group B, SP14, cross-reacted with orf and rabbit fibroma viruses. Two MAbs in group C, SP24 and SP32, cross-reacted with vaccinia, cowpox, ectromelia, and rabbit fibroma viruses. These findings indicate that at least two SPV antigens contain cross-reactive epitopes with different genera of poxviridae.

Impairment of endothelium-dependent relaxation in aorta from rats with arteriosclerosis induced by excess vitamin D and a high-cholesterol diet

The present investigation was undertaken to characterize the relaxing responsiveness in aortic strips from rats with arteriosclerosis, which was produced by excess vitamin D2 (VD) administration followed by treatment with or without a high-cholesterol diet for 6 weeks (VD + CHOL and VD group, respectively). This arteriosclerotic aorta was characterized by medial calcification and intimal cell proliferation. Helical strips of thoracic aorta were suspended in oxygenated Krebs-Henseleit solution. Under precontraction with noradrenaline, endothelium-dependent relaxations to acetylcholine were significantly attenuated in the VD and VD + CHOL as compared with the control. Relaxation to calcium ionophore A23187 was also significantly attenuated in the VD + CHOL. However, the relaxing responses to acetylcholine and A23187 in aortas from rats fed a high-cholesterol diet alone remained unaffected. Nitroglycerin caused an equal degree of relaxation in aortas from control and arteriosclerotic rats. There was a significant negative correlation between the relaxing response to acetylcholine and the calcium content in the aorta. These results indicate that in arteriosclerotic rat aortas, the endothelium-dependent relaxation to acetylcholine is impaired in proportion to the degree of calcification, and such impairment is facilitated by cholesterol feeding but can not be attributed to hypercholesterolemia or vascular cholesterol deposition.

[Use of diltiazem in the anesthetic management of epinephrine predominant pheochromocytoma]

This report describes a case of epinephrine predominant pheochromocytoma successfully managed intraoperatively with an infusion of diltiazem. A 50-yr-old woman with a 10-yr history of diabetes mellitus was admitted to the hospital because of thirst and general fatigue. A cystic left adrenal tumor was found on computed tomographic scan. Although resting plasma catecholamine levels were normal, plasma norepinephrine and epinephrine levels obtained from the left adrenal vein were 1.6 ng.ml-1 (normal, 0.04-0.35) and 6.2 ng.ml-1 (normal, less than 0.12), respectively. Diltiazem was administered i. v. at a rate of 3 micrograms.kg-1.min-1 before induction of anesthesia. Anesthesia was induced with enflurane 2-3% and nitrous oxide in oxygen, followed by tracheal intubation facilitated with vecuronium. Anesthesia was maintained with enflurane 1-3% and nitrous oxide in oxygen. Paralysis was maintained with vecuronium. Hypertension during the manipulation of the tumor was controlled by increasing the inspired concentration of enflurane or by increasing the infusion rate of diltiazem to 5 micrograms.kg-1.min-1. There was no tachyarrhythmia. The infusion of diltiazem was continued until the draining vein from the tumor had been ligated. Hypotension, after removal of the tumor, was treated by the rapid infusion of fluid. Plasma norepinephrine and epinephrine levels during tumor manipulation were 1.18 ng.ml-1 and 6.57 ng.ml-1, respectively.

Effects of the N-methyl-D-aspartate antagonists on the rise in [Ca2+]i following depolarization in aged rat brain synaptosomes

The effects of non-competitive NMDA antagonists, MK-801 and dextrorphan in relation to the rise in intracellular Ca2+ concentrations ([Ca2+]i) after stimulation with 15 mM K+ in whole brain synaptosomes from young (3 months old) and aged (24 months old) Fisher344 rats were examined. A fluorescent chelating agent, Rhod-2, was employed to monitor any alterations of K(+)-evoked [Ca2+]i. In young rats, the rise in [Ca2+]i following depolarization was affected by neither dextrorphan (1, 10, 100 microM) nor MK-801 (0.1, 1, 10 microM), while in aged rats, 1 microM dextrorphan and 0.1 microM MK-801 brought about a significant increase in [Ca2+]i following depolarization. In low Mg2+ medium, 10 microM MK-801 and 100 microM dextrorphan significantly inhibited the rise in [Ca2+]i after stimulation with 15 mM K+ in young rats, while neither dextrorphan nor MK-801 could affect the rise in [Ca2+]i significantly in aged rats. When 100 microM NMDA was applied in a medium containing 1.2 mM Mg2+, the rise in [Ca2+]i following depolarization was slightly inhibited by 1 microM MK-801 in young rats, but it was not inhibited significantly by dextrorphan. In aged rats, both 100 microM dextrorphan and 10 microM MK-801 strongly inhibited the rise in [Ca2+]i following depolarization in the presence of 100 microM NMDA. Instead of NMDA, when 100 microM alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), a non-NMDA receptor agonist, was applied, dextrorphan did not inhibit the rise in [Ca2+]i. In low Mg2+ medium, 100 microM NMDA potentiated the inhibitory effect of 10 microM dextrorphan in young rats, while 100 microM dextrorphan or MK-801 did not show any further inhibition by adding 100 microM NMDA. The addition of 100 microM AMPA did not affect the effect of dextrorphan in a low Mg2+ medium in young rats. These results suggest that NMDA antagonist-mediated [Ca2+]i homeostatic system may alter through aging. In addition, the findings that NMDA potentiated the inhibitory effect of NMDA antagonist, which being further potentiated by aging or lowered extrasynaptosomal Mg2+, indicate the possibility that the Mg2+ block to NMDA receptors might be attenuated through aging.

The facilitating and suppressing effects of delta 9-tetrahydrocannabinol on the rise in intrasynaptosomal Ca2+ concentration in rats

The effects of delta 9-tetrahydrocannabinol (delta 9-THC) on the rise in intracellular Ca2+ concentrations ([Ca2+]i) after stimulation with 15 mM or 29 mM K+ in rat whole brain synaptosomes were examined. A fluorescent chelating agent, Rhod-2, was employed to monitor any alterations of K(+)-evoked [Ca2+]i. Pretreatment with 10(-10) M delta 9-THC for 3 min enhanced K(+)-evoked [Ca2+]i significantly, while 10(-9), 10(-8) or 5 x 10(-8) M delta 9-THC significantly inhibited the K(+)-evoked [Ca2+]i. These results suggest that delta 9-THC had a biphasic effect on the K(+)-evoked Ca2+ response in rat brain synaptosomes.

Immune regulation by brain cells in the central nervous system: microglia but not astrocytes present myelin basic protein to encephalitogenic T cells under in vivo-mimicking conditions

The antigen-presenting capability of various types of brain cell, such as primary mixed glial cells, astrocytes and microglia, was examined under conditions in which Ia antigen expression on the cultured cells mimicked that in the central nervous system (CNS) of rats with experimental autoimmune encephalomyelitis (EAE). In the CNS of rats with EAE, microglia but not astrocytes express Ia antigens. To produce such conditions, cultured brain cells were treated with various concentrations of interferon-gamma (IFN-gamma). It was revealed that in vivo-like conditions were produced when cultured brain cells were treated with less than 100 U/ml IFN-gamma. Under such conditions, microglia presented an antigen, myelin basic protein (MBP), to MBP-specific T-cell lines. Astrocytes, on the other hand, did not show antigen-presenting ability, but rather suppressed T-cell proliferation. Primary mixed glial cells, mainly comprising astrocytes and microglia, were also weak antigen-presenting cells (APC). These findings suggest that brain cells comprising various types of cell with regard to APC function do not up-regulate the proliferation of encephalitogenic T cells in vivo, although a particular type of brain cell, i.e. microglia, show antigen-presenting capability.

Neurokinin A-stimulated phosphoinositide breakdown in rabbit iris sphincter muscle

Specific [3H]-substance P binding was saturable and of high affinity (KD = 2.5 nM) with a Bmax of 725 fmol/mg protein in the isolated rabbit iris sphincter muscle. The competition for [3H]-substance P binding was in the order of eledoisin greater than substance P greater than kassinin greater than neurokinin B greater than neurokinin A greater than physalaemin. In the same preparation, neurokinin A, as well as substance P induced a concentration-related accumulation of [3H]-inositol phosphates (IPs), and the maximum increase was about 200% of the control at 10(-4) M. [D-Arg1, D-Trp7,9, Leu11]-substance P (SP) and [D-Pro2, D-Trp7,9]-SP (10(-3) M) inhibited substance P or neurokinin A (10(-4) M)-induced phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis significantly. [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-SP (10(-3) M) also inhibited neurokinin A (10(-4) M)-induced PIP2 hydrolysis significantly. Neurokinin A and substance P produced concentration-related contractions in normal Ca(2+)-containing medium. The contractile response was weaker in Ca(2+)-free medium, and there was no response in 0.2 mM EGTA medium. In Ca(2+)-free medium, the basal level of [3H]-IPs accumulation was smaller than that in normal medium, and neurokinin A and substance P significantly increased PIP2 hydrolysis. In the 0.2 mM EGTA containing medium, neurokinin A and substance P did not stimulate the PIP2 hydrolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Interstitial deletion of chromosome 16q: 16q22 is critical for 16q- syndrome

Partial deletion of 16q is rare; to our knowledge only 12 cases have been published. Fryns et al. [Hum Genet 38:343-346, 1977] described the first of these cases and proposed a new clinical entity. Our patient was a girl and had many minor anomalies of the kind often observed in 16q- syndrome. Severe failure to thrive due to emesis and diarrhea were also observed. High resolution banding methods showed that the chromosome constitution of the patient was 46,XX,del(16)(q22.1q22.3). This suggests that 16q22 is critical for the syndrome.

In vivo lymphocyte-mediated myocardial injuries demonstrated by adoptive transfer of experimental autoimmune myocarditis

BACKGROUND

To elucidate the mechanisms of immune-related myocardial injuries, we examined whether autoimmune myocarditis was passively transferable by use of humoral or cellular factors.

METHODS AND RESULTS

Active myocarditis was elicited in Lewis rats by immunization with human cardiac myosin fraction in complete Freund's adjuvant. This experimental myocarditis was characterized by macroscopic features such as pericardial effusion, enlargement of the heart, and gray discoloration of the cardiac surface. Histologically, extensive myocardial necrosis and numerous inflammatory cell infiltrations were observed. Interestingly, multinucleated giant cells were frequently observed in the lesions. Transfer of the disease by the humoral factor was examined by use of fresh sera and immunoglobulin fraction of pooled sera from rats with severe myocarditis, and transfer by the cellular factor was tested by use of spleen cells and lymph node cells from the diseased rats. When naive Lewis rats were given 15.75 mg of immunoglobulin fraction, no particular change was observed in the hearts. Fresh sera also could not elicit myocarditis in recipient rats. In contrast, intravenous injection of spleen cells or lymph node cells that were cultured for 3 days in the presence of 1 microgram/ml of concanavalin A elicited severe myocarditis. The macroscopic and microscopic findings of passively transferred myocarditis are essentially the same as those found in actively induced myocarditis. Multinucleated giant cells were also observed in the lesions of transferred myocarditis.

CONCLUSIONS

This study demonstrates direct evidence for in vivo lymphocyte-mediated myocardial injuries.

Endothelium-dependent contraction produced by acetylcholine and relaxation produced by histamine in monkey basilar arteries

The present experiments were carried out to investigate the endothelium dependence of the responses to acetylcholine (ACh), arachidonic acid, and histamine in monkey basilar arteries. ACh and arachidonic acid caused endothelium-dependent contraction (EC) in both monkey and canine basilar arteries. The endothelium-derived contracting factor (EDCF) was probably thromboxane A2 (TxA2), as the EDC was attenuated by a cyclooxygenase inhibitor, TxA2 synthetase inhibitors, and TxA2 antagonists. On the other hand, histamine caused endothelium-dependent relaxation (EDR) in monkey and EDC in canine basilar arteries. The EDR in monkey basilar arteries was attenuated by a nitric oxide synthase inhibitor. The EDR and EDC were antagonized by tripelennamine but not by cimetidine, indicating that they are mediated by H1-receptors. From these results, we suggest that in the monkey basilar artery, either there are two types of endothelium (an EDCF type for ACh and arachidonic acid and an EDRF type for histamine) or there is a single type of endothelium with two types of signalling processes (one for EDC and one for EDR).

Isolation of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]cysteine from human urine

S-[2-Carboxy-1-(1H-imidazol-4-yl)ethyl]cysteine (I), a proposed precursor of 3-[(carboxymethyl)thio]-3-(1H-imidazol-4-yl)propanoic acid [Kinuta, Yao, Masuoka, Ohta, Teraoka & Ubuka (1991) Biochem. J. 275, 617-721], was isolated from healthy human urine by using ion-exchange column chromatography. Identification of the isolated compound with compound (I) was performed by physicochemical analyses involving i.r., m.s. and n.m.r. spectrometries as well as high-voltage paper electrophoresis, t.l.c. and paper chromatography. Compound (I) was synthesized in 80% yield by incubation of a reaction mixture containing trans-urocanic acid and 3-fold excess of cysteine at 70-75 degrees C. From these results we suggest that natural thiol compounds such as cysteine and GSH participate in the metabolism of urocanic acid, a key metabolite of L-histidine.

Microglial and astroglial reactions to inflammatory lesions of experimental autoimmune encephalomyelitis in the rat central nervous system

Gliosis is a repair process of lesions appearing in the central nervous system (CNS). Although gliosis by astrocytes (astrocytic gliosis) has been well documented, that by microglia (microglial gliosis) remains poorly understood. In the present study we induced experimental autoimmune encephalomyelitis (EAE) in Lewis rats and examined microglial and astroglial reactions to EAE lesions at various stages of the disease by immunohistochemistry. For the demonstration of microglia and astrocytes, antibodies against complement receptor type 3 (OX42) and glial fibrillary acidic protein (GFAP) were used, respectively. It was revealed that the whole course of microglial and astroglial reactions to EAE lesions is divisible into three stages, i.e., initial, peak and recovery stages. Microglial and astroglial reactions to EAE lesions at each stage correspond well with the clinical and histological stages of EAE. At the initial stage, rats showed mild clinical signs and a few inflammatory foci were found in the CNS. Microglia were increased in number in close association with inflammatory cell aggregates, whereas astrocytes showed no significant reaction in spite of the presence of inflammatory cells. At the peak stage, rats showed full-blown EAE and the number of inflammatory cells reached maximum. The most characteristic finding at this stage was 'encasement' of inflammatory lesions by astrocytic fibers. Microglia were increased in number, but association of microglia with lesions was prevented by astrocytes. Interestingly, however, such characteristic distribution of microglia and astrocytes was not observed at the recovery stage. Residual inflammatory cell aggregates were intermingled with dense microglial and astrocytic gliosis, forming 'micro-astroglial scars'. Double immunofluorescence staining with anti-GFAP and anti-bromodeoxyuridine (BrdU), or with OX42 and anti-BrdU revealed that BrdU-incorporated microglia, but not astrocytes, were present mainly at the initial and peak stages, suggesting that microglia would proliferate by cell division to create gliosis, whereas astrocytic gliosis would be a result of migration of astrocytes and/or up-regulation of expression of GFAP molecule. Taken together with previous in vitro findings that microglia, but not astrocytes, stimulate encephalitogenic T cell proliferation, these in vivo findings suggest that microglia augment, whereas astrocytes suppress, inflammatory processes in the CNS.

[Systemic plasmacytosis with polyclonal hypergammaglobulinemia and numerous plasma cells in the blood]

We report a patient with systemic plasmacytosis with polyclonal hyperimmunoglobulinemia who at presentation showed a blood and bone marrow picture suggestive of plasma cell leukemia. A 78-year-old woman was admitted to our hospital because of marked hepatosplenomegaly and generalized lymphadenopathy. She had leukocytosis with 42% plasmacytes, and plasma cells were increased also in her bone marrow (32.6%). She had marked polyclonal hyperimmunoglobulinemia with increased IgG, IgA and IgE. IgM and IgD were normal. She complained of cough and dyspnea. Her general condition was too poor to remove a lymph node for pathological examination. After treatment with daunorubicin, vincristine and prednisolone (DVP), her lymphadenopathy diminished rapidly, the immunoglobulins decreased and the plasma cells in her blood disappeared. She achieved a complete remission and has been in good condition without further treatment for 24 months.

Effect of nebracetam on the disruption of spatial cognition in rats

Central cholinergic hypofunction causes the disruption of spatial cognition, while cholinomimetics improve this disruption in rats. Scopolamine (0.5 mg/kg, i.p.) has also been reported to disrupt radial maze performance in rats. Nebracetam (WEB 1881 FU), a new nootropic candidate, was able to correct this scopolamine-induced disruption of spatial cognition at the dose of 10 mg/kg, p.o. Furthermore, nebracetam enhanced oxotremorine-induced tremors in mice. These results indicate that nebracetam has a cholinergic enhancing effect. The scopolamine-induced disruption of spatial cognition has been previously reported to improve not only by cholinomimetics but also by brain noradrenergic drugs such as L-threo-DOPS and amantadine. Nebracetam reversed the change of brain noradrenaline contents in the frontal cortex and hippocampus in which the noradrenaline content decreased by treatment with scopolamine. Nebracetam also decreased the delta 9-tetrahydrocannabinol (6 mg/kg, i.p.)-induced disruption of spatial cognition, which was reported to be related to the lymbic noradrenergic function. These results suggest that the cognitive enhancing effect of nebracetam involves not only cholinergic mechanisms but also involves lymbic and hippocampal noradrenergic mechanisms.

Histological characteristics of lupus nephritis in F1 mice with chronic graft-versus-host reaction across MHC class II difference

Renal lesions at the chronic phase of MHC class-II-disparate graft-versus-host reaction (GVHR) were examined. To induce GVHR, C57BL/6 (B6) spleen cells were injected twice into either (B6 x bm12)F1 (class-II-disparate), (B6 x bm1)F1 (class-I-disparate) or (bm1 x bm12)F1 mice (class-I + II-disparate). For comparison, (C57BL/10 x DBA/2)F1 (BDF1) mice injected with DBA/2 spleen cells were also used. (B6 x bm12)F1 and BDF1 recipients showed marked elevation of anti-DNA antibodies, circulating immune complexes (CIC) and the number of immunoglobulin producing cells (IgPC). At 20 weeks after cell injection, severe immune complex glomerulonephritis (ICGN) was observed in (B6 x bm12)F1 recipients, but was far less severe in (bm1 x bm12)F1 recipients and was not observed in (B6 x bm1)F1 recipients. ICGN was also observed in BDF1 recipients at 12 weeks after cell injection. By immunofluorescent microscopy, IC deposition was detected along the capillary loops and also in the mesangial area in (B6 x bm12)F1 recipients, while BDF1 recipients showed only a capillary pattern. By light microscopy, the renal lesion of (B6 x bm12)F1 recipients appeared similar to those of BDF1 recipients. Histologically, (B6 x bm12)F1 recipients serve as a good model for lupus glomerulonephritis induced by class-II-disparate GVHR.