A cell fusion-inhibiting monoclonal antibody binds to the presumed stalk domain of the human parainfluenza type 2 virus hemagglutinin-neuraminidase protein

Previously, we obtained a neutralizing monoclonal antibody directed against the hemagglutinin-neuraminidase (HN) protein of human parainfluenza type 2 virus (PIV2), which was able to prevent cell fusion without affecting the hemagglutinating and neuraminidase activities. In this study, four escape mutants of PIV2 have been obtained under pressure of the monoclonal antibody. Intriguingly, the HN protein of each mutant proved to have two amino acid substitutions, one of which is at 83Asn or 91Lys, and another one is at 150Leu, 160Ala, or 186Met. One mutant designated F13, which has substitutions at 83Asn and 186Met in the HN protein, could not cause cell fusion in HeLa cells despite its multiple replication, while the other mutants formed typical syncytial cells. The deduced amino acid sequence of F13 fusion (F) protein proved to be identical to that of wild-type F protein, and furthermore, protein expression analyses have revealed that the low-fusion phenotype of F13 was due to its mutated HN protein, whose antigenicity to the monoclonal antibody was abolished by the single mutation at 83Asn. These observations have suggested that the principal epitope for the monoclonal antibody resides in the presumed stalk domain of the HN protein, which may play an important role in promoting cell fusion.

Noradrenaline inhibits preoptic sleep-active neurons through alpha 2-receptors in the rat

Effects of noradrenaline (NA) on the activity of sleep-related neurons in the preoptic area (POA) and the neighboring basal forebrain were examined in the rat. Of 36 sleep-active neurons tested, 19 were inhibited and the other 17 were unaffected by NA applied through a multibarrel pipette. The alpha 2-agonist clonidine inhibited 11 of 14 sleep-active neurons and did not affect the other 3 neurons, whereas the alpha 1-agonist methoxamine (n = 13) and the beta-agonist isoproterenol (n = 11) had no effect on any of the sleep-active neurons tested. Thus, alpha 2-receptors mediated the NA-induced inhibition. Of 22 waking-active neurons tested, NA excited 10, inhibited 1, and had no effect on the remaining 11. Methoxamine excited 4 of 13 waking-active neurons tested, whereas isoproterenol (n = 9) and clonidine (n = 4) were without effect on any of the waking-active neurons tested. Accordingly, alpha 1-receptors probably mediated the NA-induced excitation. Seventy-seven state-indifferent neurons, which lacked activity related to the sleep-waking state, and 20 paradoxical sleep-active neurons were mostly (65%-70%) insensitive to NA. These results suggest that NA promotes wakefulness by inhibiting sleep-active neurons and by exciting waking-active neurons.

Prostaglandins and sleep

The concept of humoral regulation of sleep was initially proposed by a French neuroscientist, Henri Piéron of Paris, in the first decade of this century. He and his associate Legendre were the first to show the presence of a sleep-inducing substance in the cerebrospinal fluid (CSF) of sleep-deprived dogs. Concurrently and independently, Kuniomi Ishimori of Nagoya University, Nagoya, Japan, employing a similar experimental approach, also demonstrated a sleep-inducing substance in the CSF of sleep-deprived dogs. During the next 80 years or so, more than 30 so-called endogenous sleep substances have been reported to exist in the brain by numerous investigators, CSF, and other organs and tissues of mammals. However, their physiological relevance has remained uncertain in most instances. In this review, we shall focus upon our own work concerning the molecular mechanisms of sleep-wake regulation by prostaglandins (PGs) D2 and E2, with special emphasis on the recent developments during the last several years.

Prostaglandin D2-sensitive, sleep-promoting zone defined in the ventral surface of the rostral basal forebrain

The site of action for the sleep-promoting effect of prostaglandin (PG) D2 was extensively examined in the brain of adult male rats (n = 231). PGD2 was administered at 100 pmol/0.2 microliter per min for 6 hr (2300-0500 hr) through chronically implanted microdialysis probes or infusion cannulae. Among the administrations of PDG2 by dialysis probes (n = 176), only those (n = 8) to a ventro-rostral part of the basal forebrain by the probes implanted on the midline consistently increased slow-wave sleep (SWS), by 51 +/- 6 min (mean +/- SEM) above the baseline value (111 +/- 11 min). Since this area is separated by a cleft into right and left regions, the results were interpreted to mean that, through this cleft, PGD2 diffused in the subarachnoid space over the adjacent ventral surface, where it had the effect of promoting sleep. When PGD2 was directly infused into the subarachnoid space (n = 55), extraordinary increases exceeding 90 min were consistently attained for the SWS at sites located between 0.5 and 2 mm rostral to the bregma and between 0 and 1.2 mm lateral to the midline defined according to the stereotaxic coordinates adopted from the brain atlas of Paxinos and Watson [Paxinos, G. & Watson, C. (1986) The Rat Brain in Stereotaxic Coordinates (Academic, San Diego)]. Thus, we demarcated a "PGD2-sensitive, sleep-promoting zone" within this region in the ventral surface of the rostral basal forebrain. During the bilateral infusion of PGD2 into the subarachnoid space of this zone, the hourly mean SWS level of the nocturnal animals (n = 6) in the night reached the maximum at the second hour of the infusion period; this maximum hourly SWS level, corresponding to the daytime level of the same animals, lasted until the end of PGD2 infusion.

Bond strength of adhesive resin to three nickel-chromium alloys with varying chromium content

This in vitro study evaluated the influence of chromium content on bond strength and durability between nickel-chromium alloys and an adhesive resin that contained 4-methacryloxyethyl trimellitate anhydride. Three nickel-chromium alloys with different chromium content, as well as pure chromium and pure nickel metals, were bonded and tested for shear strength. After repeated thermocycling, shear bond strength decrease was lower in alloys containing high chromium content. Pure chromium metal demonstrated a 15.2% decrease, whereas pure nickel metal demonstrated the greatest (53.7%) decrease. The results suggest that nickel-chromium alloys with higher chromium content are desirable for 4-methacryloxy-ethyl trimellitate anhydride resin-bonded restorations.

Fusion properties of cells constitutively expressing human parainfluenza virus type 4A haemagglutinin-neuraminidase and fusion glycoproteins

We established HeLa cell lines that constitutively expressed the fusion (F) and/or haemagglutinin-neuraminidase (HN) glycoproteins of human parainfluenza virus type 4A (PIV-4A) and used them to analyse the roles of these glycoproteins in virus-induced cell fusion. No syncytium formation occurred, even in HeLa cells expressing both the F and HN proteins (HeLa-4aF+HN cells). Also no syncytium was found in a mixed culture of cells expressing the F protein (HeLa-4aF) and the HN protein (HeLa-4aHN). Syncytia were observed in HeLa-4aF cells transfected with the HN gene, but no syncytium formation was found in HeLa-4aHN cells transfected with the F gene. Co-cultivation of HeLa-4aF+HN cells with HeLa-4aF cells generated large polykaryocytes, whereas co-cultivation with HeLa-4aHN cells induced no cell fusion. Infection of HeLa-4aF cells with PIV-4A generated large syncytia and degenerated nuclei, whereas little or no polykaryocytes were found in HeLa-4aHN cells infected with PIV-4A. From the above findings, the following conclusions were drawn: (i) the expression of both the F and HN proteins in the same cell is necessary for cell fusion; (ii) the expression of the F protein alone enhances susceptibility to cell fusion; (iii) the constitutive expression of the HN protein promotes resistance to paramyxovirus-induced cell fusion.

Promotion of sleep by prostaglandin D2 in rats made insomniac by pretreatment with para-chlorophenylalanine

The correlation between the somnogenic effect of prostaglandin (PG) D2 and the serotoninergic system was examined in freely-moving rats (n = 64) by use of a continuous infusion method. Rats pretreated with para-chlorophenylalanine (PCPA: 450 mg/kg body weight, i.p.) or non-PCPA-pretreated rats received infusion of PGD2, serotonin, or its direct precursor, 5-hydroxytryptophan (5HTP), into their third cerebral ventricle at a rate of 100 pmol/0.2 microliter/min between 11:00 and 17:00 h. In the PCPA-pretreated insomniac rats, PGD2 infusion resulted in an immediate increase in slow-wave sleep (SWS) and an increase with a 2-h latency in paradoxical sleep (PS). The total amounts of SWS and PS during the PGD2-infusion period were 151% and 154% of the respective control values. These results indicate that inhibition of the biosynthesis of serotonin and 5HTP by PCPA marginally affects the sleep-promoting effect of PGD2. The transient sleep restoration produced by 5HTP infusion into PCPA-pretreated rats was hardly affected by the simultaneous infusion (200 pmol/0.2 microliter/min; 07:00-17:00 h) of diclofenac sodium, an inhibitor of cyclo-oxygenase, suggesting that PGD2 production is not critically involved in the sleep restoration by 5HTP. The sleep-promoting property of PGD2 is thus probably independent of the serotoninergic modulation of sleep-wake activity.

Induction patterns of Fos-like immunoreactivity in the forebrain as predictors of atypical antipsychotic activity

Clozapine and haloperidol produce different induction patterns of c-fos expression in the forebrain, with haloperidol increasing Fos-like immunoreactivity (FLI) in the striatum, nucleus accumbens, lateral septal nucleus and clozapine producing such effects in the nucleus accumbens, prefrontal cortex and lateral septal nucleus. Accordingly, it was deemed possible that this approach may be useful in characterizing compounds with known or suggested antipsychotic actions. We therefore examined the effects of 17 compounds considered to be either typical, or atypical, antipsychotics on FLI in the prefrontal cortex, medial and dorsolateral striatum, nucleus accumbens and the lateral septal nucleus. Consistent with the hypothesis that the prefrontal cortex may be a target for some antipsychotic actions, FLI was elevated in this structure by clozapine, ICI 204,636, fluperlapine, RMI-81,582, remoxipride, molindone, melperone and tiospirone. Likewise, the ability of all of the compounds, except for risperidone, to enhance FLI in the lateral septal nucleus suggests that this limbic region also may be an important locus of antipsychotic action. All of the compounds examined elevated FLI in the nucleus accumbens and medial striatum, indicating that potential antipsychotic activity is predicted most consistently on this basis. Neuroleptics with a clearly documented liability for producing extrapyramidal side effects (EPS) such as chlorpromazine, fluphenazine, haloperidol, loxapine, metoclopramide and molindone elevated FLI in the dorsolateral striatum. In contrast, compounds unlikely to produce EPS such as clozapine, thioridazine, risperidone, remoxipride, fluperlapine, sulpiride, melperone and RMI-81,582 either failed to increase or produced minor elevations in FLI in the dorsolateral striatum.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of fusion regulatory proteins (FRPs) on human peripheral blood monocytes. Induction of homotypic cell aggregation and formation of multinucleated giant cells by anti-FRP-1 monoclonal antibodies

Fusion regulatory proteins (FRPs) are newly defined cell surface molecules that enhance and/or induce virus-mediated cell fusion. Anti-FRP-1 Abs reacted with all of the established cells derived from humans and monkeys, whereas FRPs were found to be selectively expressed on a fraction of monocytes in human PBMCs. Granulocytes expressed no FRP-1 molecules, but approximately 18% of granulocytes expressed FRP-2 molecules. Alveolar macrophages also expressed FRP-1 molecules. FRP-1 expression was enhanced by culture of monocytes, but CD14 expression was not influenced by cultivation. Anti-FRP-1 Abs induced homotypic cell aggregation and multinucleated giant cell formation of monocytes. Anti-beta 2 integrin Ab blocked anti-FRP-1 Ab-induced cell aggregation, and anti-beta 1 integrin Ab and fibronectin inhibited anti-FRP-1 Ab-induced polykaryocyte formation. There was no competitive binding to monocytes between anti-FRP-1 Ab and anti-beta 1 or anti-beta 2 integrin Ab or fibronectin. Furthermore, there was no enhancement of beta 1 and beta 2 integrin expression by anti-FRP-1 Ab on monocytes. These findings suggest that anti-FRP-1 Ab activated integrin systems, and that the functions of anti-FRP-1 Ab were demonstrated through the activated integrin systems. Furthermore, it is inferred that integrin systems are involved in polykaryocyte formation of monocytes.

Expression of fusion regulatory proteins (FRPs) on human peripheral blood monocytes. Induction of homotypic cell aggregation and formation of multinucleated giant cells by anti-FRP-1 monoclonal antibodies

Fusion regulatory proteins (FRPs) are newly defined cell surface molecules that enhance and/or induce virus-mediated cell fusion. Anti-FRP-1 Abs reacted with all of the established cells derived from humans and monkeys, whereas FRPs were found to be selectively expressed on a fraction of monocytes in human PBMCs. Granulocytes expressed no FRP-1 molecules, but approximately 18% of granulocytes expressed FRP-2 molecules. Alveolar macrophages also expressed FRP-1 molecules. FRP-1 expression was enhanced by culture of monocytes, but CD14 expression was not influenced by cultivation. Anti-FRP-1 Abs induced homotypic cell aggregation and multinucleated giant cell formation of monocytes. Anti-beta 2 integrin Ab blocked anti-FRP-1 Ab-induced cell aggregation, and anti-beta 1 integrin Ab and fibronectin inhibited anti-FRP-1 Ab-induced polykaryocyte formation. There was no competitive binding to monocytes between anti-FRP-1 Ab and anti-beta 1 or anti-beta 2 integrin Ab or fibronectin. Furthermore, there was no enhancement of beta 1 and beta 2 integrin expression by anti-FRP-1 Ab on monocytes. These findings suggest that anti-FRP-1 Ab activated integrin systems, and that the functions of anti-FRP-1 Ab were demonstrated through the activated integrin systems. Furthermore, it is inferred that integrin systems are involved in polykaryocyte formation of monocytes.

3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) induces gene mutations and inhibits metabolic cooperation in cultured Chinese hamster cells

Investigations were carried out on 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent direct-acting bacterial mutagen found in chlorinated tap water, for the potential to induce 6-thioguanine (6-TG) resistant mutations in cultured Chinese hamster V79 cells. The mutagenicity of MX was manifested when cells were treated with MX in Hanks balanced salt solution, but not in serum-free Eagle's minimal essential medium. A 12-fold higher mutation frequency over control was obtained at 12.5 micrograms/ml MX. In addition, the inhibitory effect of MX on metabolic cooperation between cocultivated 6-TG- sensitive (6-TGs) and -resistant (6-TGr) V79 cells was investigated. Recovery of 6-TGr cells significantly increased at 0.8-2.0 micrograms/ml MX due to impaired intercellular communication with 6-TGs cells. MX is believed to exert tumor-promoting and mutagenic activity in mammalian cells.

[Acetylcholinesterase in the erythrocyte membrane]

Acetylcholinesterase (AchE) in erythrocytes is one of the typical extraneural AchEs. Its activity is high in human erythrocytes. It has been known that the enzyme is present only in the membrane in erythrocytes and that it is localized on the outer side of the membrane. Recent studies have disclosed much of the primary structure of AchE and the membrane anchor structure. However, the physiological functions of erythrocyte AchE are still totally unknown. Nevertheless, the enzyme may be regarded as a model of AchE in the nervous system. In addition, it may be used to examine the status of the erythrocyte membrane. The enzyme activity seems useful as an indicator of the effects of AchE inhibitors, such as pesticides. It should be noted, however, that the activity of AchE in erythrocytes is not always a good indicator of intoxication with AchE inhibitors.

Effects of prostaglandin D2, lipoxins and leukotrienes on sleep and brain temperature of rats

Prostaglandin (PG) D2 and four lipoxygenase-derived eicosanoids [lipoxins (LX) A4 and B4, and leukotrienes (LT) C4 and D4] were examined for their effects on sleep and brain temperature in freely-behaving rats. In the first series of experiments, PGD2 was infused into the third ventricle at four different locations between 23:00 and 05:00. In a location apposed to the medial preoptic area (MPO), PGD2 at doses 1, 10 and 100 pmol/min, increased the slow wave sleep (SWS) by 23% (p < or = 0.01), 35% (p < or = 0.05) and 44% (p < or = 0.01), respectively, during the infusion period. In the second series of experiments, LXs and LTs were infused at the location apposed to MPO. Significant increases in SWS were detected with LXA4 at 100 pmol/min (14%, p < or = 0.05), LXB4 at 100 pmol/min (20%, p < or = 0.05), and LTD at 10 pmol/min (17%, p < or = 0.05). An increase in paradoxical sleep (PS) was produced by PGD2 at 1 and 10 pmol/min infusion (p < or = 0.05), but not by any of the lipoxygenase-derived eicosanoids examined. PGD2 also elevated the mean brain temperature during infusion by 0.2 degrees C and 0.9 degrees C at infusion doses 10 and 100 pmol/min, respectively. But PGD2 infusion at 1 pmol/min did not elevate the brain temperature. LXs (excluding LXB4 at 100 pmol/min) and LTs did not alter the brain temperature significantly at the tested doses. We conclude that PGD2 is the most effective sleep promoter among the eicosanoids examined so far.

Three-body wear of four types of light-activated composite resin veneering materials

The in vitro wear resistance of four types of light-activated composite resins designed for crown and bridge veneers was determined by means of a three-body wear-testing device. After repeated cycles of loading, the wear values were measured with a profilometer, and surface textures were observed through a scanning electron microscope. All of the composite resin veneering materials examined in this investigation exhibited greater wear resistance than an unfilled poly(methyl methacrylate)-based material. The worn surface of veneering materials demonstrated outlines of fillers, indicating the difference in wear resistance between the resin matrix and the filler.

Molecular and biological characterization of fusion regulatory proteins (FRPs): anti-FRP mAbs induced HIV-mediated cell fusion via an integrin system

Anti-FRP mAbs induced polykaryocyte formation of U2ME-7 cells (CD4+U937 cells transfected with the HIV gp160 gene). Anti-FRP-1 mAb immunoprecipitated gp80-85, gp120 and homodimers of these peptides, and anti-FRP-2 mAb reacted with gp135 identically to the alpha 3 subunit of integrin. Both anti-FRP-1 and anti-FRP-2 mAb-induced cell fusion was blocked by anti-beta 1 integrin antibody, fibronectin or inhibiting anti-FRP-1 antibody. Therefore, anti-FRP mAbs were thought to induce the fusion via an integrin system(s). FRP-mediated fusion was temperature, cytoskeleton, energy and Ca2+ dependent. These experiments showed a possible regulatory function of cell fusion by an integrin system(s).

Temporal approach for reduction of zygomatic fractures. Clinical results and advantages of the technique

We have used closed reduction based on Gillies' method using an original Y-shaped zygomatic elevator in 50 cases after radiographic evaluation of the displacement by three directional radiography. No patients had residual restriction of mandibular motion, double vision or facial asymmetry. Radiography showed poor reduction in two cases, and displacement of the initial reduction in three. In all other cases, satisfactory results were achieved.

HN proteins of human parainfluenza type 4A virus expressed in cell lines transfected with a cloned cDNA have an ability to induce interferon in mouse spleen cells

Primary monkey kidney cells infected with human parainfluenza type 4A virus (HPIV-4A) were treated with various concentrations of formaldehyde. Formaldehyde (0.275%) treatment completely blocked virus production. However, when mouse spleen cells were cocultured with the fixed virus-infected cells, interferon was produced in the culture fluid. On the other hand, when mouse spleen cells were incubated with the fixed virus-infected cells in the presence of anti-HPIV-4A antiserum or a mixture of anti-HN protein monoclonal antibodies, interferon activity could scarcely be detected in the culture fluid. These findings indicated that the fixed virus-infected cells had an ability to induce interferon in mouse spleen cells and that the HN protein was related to interferon induction. Subsequently, a recombinant plasmid was constructed by inserting the cDNA of the HN gene of HPIV-4A into a pcDL-SR alpha expression vector. Mouse spleen cells produced interferon when cocultured with COS7 cells transfected with the recombinant plasmid, but did not when cocultured with COS7 cells transfected with the vector alone. Furthermore, we established HeLa cells constitutively expressing HPIV-4A HN (HeLa-4aHN cells) or F protein (HeLa-4aF cells). Type I (alpha/beta) interferon was detected in culture fluids of mouse spleen cells with HeLa-4aHN cells, but was not detected in those with HeLa-4aF cells. Therefore, it was concluded that the HN glycoproteins on the cell surface were sufficient for interferon induction to occur.

Noradrenergic inputs to sleep-related neurons in the preoptic area from the locus coeruleus and the ventrolateral medulla in the rat

Responses of sleep-related neurons in the preoptic area (POA) to stimulation of the locus coeruleus (LC) and the ventrolateral medulla (VLM), components of the reticular activating system, were recorded in the unanesthetized, head-restrained rat. Single-pulse stimulation of the LC and the VLM, respectively, inhibited 50% and 54% of 30 sleep-active neurons and excited 47% and 67% of 34 waking-active neurons. The remaining neurons were mostly unaffected. Seventy-three neurons that were not related to a sleep-wake state were mostly (i.e., 73-80%) unresponsive to stimulation. The high incidence of responses by sleep-related neurons suggests that neural inputs from the LC and VLM regulate the hypnogenic mechanisms in the POA. Stimulation of the LC antidromically activated 15% of sleep-active neurons and 11% of waking-active neurons. Thus, some of the sleep-related neurons in the POA may regulate LC neurons. In a later stage of the experiment, we used isoflurane-anesthetized rats that had been used for recording sleep-related neurons. Antagonists for adrenoceptors at a concentration of 10 microM were applied to neurons through a multibarrel micropipette to examine the involvement of noradrenaline in the responses as a neurotransmitter. Application of the alpha 2-blocker, yohimbine, attenuated the inhibitory responses in all 7 neurons tested. The beta-blocker, timolol, and the alpha 1-blocker, prazosin, did not alter any of the inhibitory responses. On the other hand, timolol attenuated the excitatory responses in 4 of 7 neurons, and prazosin attenuated the excitatory responses in 5 of 12 neurons. Yohimbine did not affect the excitatory responses. Thus, the LC and the VLM probably inhibit sleep-active neurons through alpha 2-adrenoceptors and excite waking-active neurons through either beta- or alpha 1-adrenoceptors.

Aggressive wound closure for elderly patients with burns

Elderly patients with burns who were age 70 years or older and who were admitted to Tokyo Medical College Hospital from 1981 to 1992 were evaluated. Among 63 patients with burns, operations were performed in 35. Of the 63, 18 patients died (six after operation). Aggressive surgical wound closure with dermolipectomy, which we have been performing since 1986, obtained statistically significantly earlier wound closure compared with conventional methods. In cases with a burn index of 10 to 30, the number of fatalities was significantly lower. In addition, the lowering of the ability of daily life and mental status after the wound closure was statistically and significantly smaller. From these facts, aggressive wound closure with dermolipectomy appears appropriate for elderly patients with burns.

Lidocaine attenuates both mechanical and metabolic changes induced by hydrogen peroxide in the rat heart

The effect of lidocaine on the hydrogen peroxide (H2O2)-induced mechanical and metabolic changes was studied in the Langendorff rat heart, which was perfused aerobically at a constant flow rate and paced electrically. H2O2 (600 microM) increased the left ventricular end-diastolic pressure (i.e., mechanical dysfunction), decreased the tissue levels of ATP and creatine phosphate (i.e., metabolic change), and increased the tissue level of malondialdehyde (MDA). The mechanical and metabolic alterations induced by H2O2 were attenuated by lidocaine (50 or 200 microM). Lidocaine also attenuated the H2O2-induced increase in MDA. Nevertheless, lidocaine modified neither the myocardial ferrylmyoglobin level that was increased by H2O2 nor the H2O2 concentration in vitro and did not affect the mechanical function and energy metabolism of the normal heart. These results suggest that lidocaine attenuates both mechanical and metabolic changes induced by exogenous H2O2. The protective action of lidocaine on the H2O2-induced changes is due to neither energy-sparing nor H2O2-scavenging effect, but probably due to its effect to reduce the H2O2-induced lipid peroxidation.

Effect of an adhesive primer on the integrity of occlusal veneer-metal interface and wear of composite resin veneered restorations

This study examines the influence of a metal-resin bonding agent on the wear rate of composite resin veneer. The specimens were prepared with a silver-based casting alloy and a light-cured composite veneering material. After application of repeated loading through a three-body wear testing device, the amount of wear was measured. The results showed no significant difference in wear between bonded and nonbonded specimens on the 1.5 mm areas of the veneer-metal interface. However, the bonded specimens exhibited significantly lower wear values at the veneer-metal interface. The use of an adhesive primer effectively enhanced the integrity of the occlusal veneer-metal junction.

Intravenous administration of inorganic selenium compounds, inhibitors of prostaglandin D synthase, inhibits sleep in freely moving rats

Prostaglandin (PG) D2 has been postulated to be an endogenous sleep-promoting factor. Biosynthesis of PGD2 is catalyzed by PGD synthase (prostaglandin-H2 D-isomerase, EC 5.3.99.2), the activity of which is inhibited by inorganic selenium compounds such as SeCl4 and Na2SeO3. We recently examined the effect of intracerebroventricular administration of these selenium compounds on sleep in rats, and demonstrated time- and dose-dependent sleep inhibition. To establish whether this effect of selenium is also produced when the compound is administered systemically, we devised a procedure for intravenous catheterization and examined the effect of these selenocompounds on sleep-wake activity in freely moving rats (n = 35). Each test compound was administered into the inferior vena cava continuously between 11.00 and 17.00 h on the experimental day. SeCl4 time- and dose-dependently inhibited sleep at infusion rates of 5, 7.5, 10 and 20 nmol/microliters per min. During the SeCl4 infusion at 20 nmol/microliters per min, slow-wave sleep and paradoxical sleep were reduced to 63% and 50% of their respective baseline values. Na2SeO3 exhibited a similar sleep inhibition, though Na2SO3 was ineffective. Infusion of SeCl4 at 10 nmol/microliters per min or below produced no consistent changes in the mean brain temperature, or food and water intake during the infusion period. During the nocturnal period subsequent to SeCl4 infusion, sleep was increased by a rebound phenomenon, while a decrease in brain temperature and inhibition of food and water intake dose-dependently occurred. We conclude that systemic administration of these PGD synthase inhibitors has a sleep-reducing potency.

Localized three-body wear of six types of composite resin veneering materials

The wear resistance of six types of composite resin veneering materials was determined in vitro by use of a three-body wear-testing device. This investigation examined the wear characteristics of the veneering composite resins in heavy occlusal contact areas. After repeated cyclic loading, wear values were measured with a profilometer, and surface textures were evaluated with a scanning electron microscope. All of the composite resin veneering materials were significantly more wear resistant than unfilled acrylic resin; but the composite resin materials demonstrated rougher surfaces than unfilled resin. Three of the composite resins exhibited fractures in the contact areas.

Antigenic and molecular properties of Murayama virus isolated from cynomolgus monkeys: the virus is closely related to avian paramyxovirus type 2

A new virus that belonged to a member of paramyxovirus was isolated from cynomolgus monkeys showing respiratory disorders about 20 years ago and was named Murayama virus (MrV). Interestingly, it showed no serological relationship with the mammalian paramyxoviruses tested. On the other hand, it was related to Yucaipa (YuV) and Bangor virus (BaV) belonging to avian paramyxovirus type 2 (PMV2). In analysis using anti-MrV monoclonal antibodies, MrV showed the closest relationship with YuV, and furthermore some conserved epitopes were found among avian paramyxovirus, MrV, YuV, BaV, and Newcastle disease virus (NDV). Subsequently, the nucleotide sequences of the F and HN genes of MrV were determined. In comparison with the deduced amino acid sequence of MrV and other paramyxoviruses, MrV showed the highest homology with NDV and higher similarity to HPIV2 group rather than to HPIV1 group. The present study clearly indicates that MrV belongs to PMV2 adapting to monkeys.