Involvement of TRPV1 and AQP2 in hypertonic stress by xylitol in odontoblast cells.

AIM: To examine the responses of mouse odontoblast-lineage cell line (OLC) cultures to xylitol-induced hypertonic stress. METHODOLOGY: OLCs were treated with xylitol, sucrose, sorbitol, mannitol, arabinose and lyxose. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. The expression of transient receptor potential vanilloids (TRPV) 1, 3 and 4 was detected using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The expression of aquaporin (AQP) 2 was detected using immunofluorescence and Western blotting analysis. The expression of interleukin-6 (IL-6) under xylitol-induced hypertonic stress was assessed using an enzyme-linked immunosorbent assay (ELISA). Small interfering ribonucleic acid (siRNA) for AQP-2 was used to inhibition assay. RESULTS: Xylitol-induced hypertonic stress did not decrease OLC viability, unlike the other sugars tested. OLCs expressed TRPV1, 3 and 4 as well as AQP2. Xylitol inhibited lipopolysaccharide (LPS)-induced IL-6 expression after 3 h of hypertonic stress. TRPV1 mRNA expression was upregulated by xylitol. Costimulation with HgCl2 (AQP inhibitor) and Ruthenium red (TRPV1 inhibitor) decreased cell viability with xylitol stimulation. OLCs treated with siRNA against TRPV1 exhibited decreased cell viability with xylitol stimulation. CONCLUSION: OLCs have high-cell viability under xylitol-induced hypertonic stress, which may be associated with TRPV1 and AQP2 expressions.

Plasmodium falciparum-infected erythrocytes form spontaneous erythrocyte rosettes.

Erythrocytes infected with trophozoites or schizonts of Plasmodium falciparum bind uninfected erythrocytes, leading to rosette formation. Both established laboratory strains and fresh isolates from patients form such rosettes, but at widely different frequencies. IgG preparations from the serum of some P. falciparum-immune donors and heparin inhibited rosette formation. The results indicate that cytoadherence of infected erythrocytes to endothelial cells and rosetting represent distinct genetic traits.

Combining site specificities of mouse hybridoma antibodies to dextran B1355S.

The combining sites of 12 mouse hybridoma antibodies to dextran B1355S have been characterized by quantitative precipitin assay. All antibodies preferentially bind the immunizing antigen B1355S and two other class I dextrans, B1498S and B1501S, but show substantial differences in the extents to which they cross react with class I dextrans, suggesting their clustering into five groups. Three myeloma proteins, CAL20 TEPC1035, J558, and MOPC104E, which bind dextran B1355S, each fall into a different group. There appears to be a substantial, but imperfect, correlation of DH region structure and individual idiotypic determinants with dextran binding patterns. Proteins with RY DH segments and IdI (J558) idiotypes are in groups 1 or 3, and proteins with YD DH segments and IdI (MOPC104E) idiotypes are exclusively in group 5. However, identical patterns of precipitin curves accompany very different sequences in CDR3. Antibodies of group 1, which react only with class II dextrans, differ the most in primary sequence, a finding suggesting that subsites responsible for cross reactivity with class I dextrans may be blocked and that this may be effected by side chains of different amino acids. This finding delineates a new aspect of the relationship of variability in amino acid sequence to antibody complementarity.

Visualization of tumor-related blood vessels in human breast by photoacoustic imaging system with a hemispherical detector array.

Noninvasive measurement of the distribution and oxygenation state of hemoglobin (Hb) inside the tissue is strongly required to analyze the tumor-associated vasculatures. We developed a photoacoustic imaging (PAI) system with a hemispherical-shaped detector array (HDA). Here, we show that PAI system with HDA revealed finer vasculature, more detailed blood-vessel branching structures, and more detailed morphological vessel characteristics compared with MRI by the use of breast shape deformation of MRI to PAI and their fused image. Morphologically abnormal peritumoral blood vessel features, including centripetal photoacoustic signals and disruption or narrowing of vessel signals, were observed and intratumoral signals were detected by PAI in breast cancer tissues as a result of the clinical study of 22 malignant cases. Interestingly, it was also possible to analyze anticancer treatment-driven changes in vascular morphological features and function, such as improvement of intratumoral blood perfusion and relevant changes in intravascular hemoglobin saturation of oxygen. This clinical study indicated that PAI appears to be a promising tool for noninvasive analysis of human blood vessels and may contribute to improve cancer diagnosis.

An enzyme-linked immunosorbent assay (ELISA) for quantification of antibodies to Streptococcus mutans surface antigens.

An ELISA was developed to quantitate the level of antibodies to various cell surface antigens of the Gram positive bacterium, Streptococcus mutans. Whole cells and purified cell wall components of S. mutans, lipoteichoic acid (LTA) from Streptococcus pyogenes, and dextran T 2000 were employed as coating antigens in this study. Cell walls of S. mutans were purified by mechanical disruption of whole cells followed by differential centrifugation and proteolytic enzyme treatment. Serotype-specific carbohydrate was purified from an autoclaved, lyophilized S. mutans whole cell preparation by column chromatography. LTA was prepared by Sepharose 4B chromatography of a phenol-water extract of S. pyogenes and used for detection of anti-polyglycerophosphate (PGP) antibodies. A rabbit antiserum to S. mutans 6715 (serotype g), which precipitated with purified carbohydrate antigen (RR g), gave good reactions with purified cell walls and whole cells of S. mutans 6715, less activity with RR g and low activity to LTA and dextran when tested by ELISA. Adsorption of this antiserum with whole cells of S. pyogenes resulted in antibody activity with specificity only to the serotype carbohydrate. The specificity of the antibody for homologous coating antigen was RR g greater than cell wall greater than whole cells. An antiserum to S. mutans MT573 (serotype e) contained antibody predominantly to LTA, whereas, anti-S. mutans MT703 (serotype e) reacted with both dextran and LTA; however, the activity to LTA was removed by prior adsorption of the antiserum with S. pyogenes cells. This treatment did not alter the antibody activity to dextran. To establish the sensitivity of ELISA, a purified IgG anti-serotype carbohydrate antibody was prepared by adsorption of anti-S. mutans 6715 antiserum with a mutant of S. mutans which lacks serotype carbohydrate followed by adsorption and elution of specific antibodies from S. mutans 6715 whole cells. The minimum level of sensitivity of ELISA was 12.5 ng of IgG anti-serotype carbohydrate.

Immunochemical studies of mouse monoclonal antibodies to dextran B1355S--II. Combining site specificity, sequence, idiotype and affinity.

The specificities of the combining sites of 19 mouse monoclonal antibodies to dextran B1355S have been characterized immunochemically by quantitative precipitin and precipitin inhibition assays; association constants for B1355S were determined by affinity gel electrophoresis. Cross-reactive and individual idiotypes related to the BALB/c B1355S-binding myeloma proteins MOPC104E [IdI(MOPC104E)] and J558 [IdI(J558)], determined by a radioimmunoassay, and heavy-chain variable-region sequences, are presented. Antibodies to B1355S are "alpha (1----3) alpha (1----6)-specific" as determined by precipitin and precipitin inhibition assays with dextrans and oligosaccharides, respectively, containing alternating alpha (1----3) alpha (1----6) linkages compared with oligosaccharides composed solely of alpha (1----3) or alpha (1----6) linkages; all antibodies have low association constants (less than or equal to 10(5) ml/g). However, there is also considerable diversity among the proteins as seen in the five groups of different patterns of reactivity with numerous dextrans having different structures, and the variability in affinity even among antibodies showing the same fine specificity by precipitin assay. There is little observable correlation of heavy-chain variable-region amino-acid sequence with specificity or affinity; however, all proteins having D-region amino acids Tyr,Asp at positions 96,97 express the MOPC104E individual idiotype and belong to precipitin specificity group 5, the group most cross-reactive with numerous dextrans, whereas those proteins having the J558 individual idiotype, Arg,Tyr or Asn,Tyr at 96,97 are found in all five precipitin groups.

A plaque assay for assessment of immune responses to Streptococcus mutans cell wall carbohydrate.

A plaque-forming cell (PFC) assay has been developed for measurement of single cell responses to the serotype carbohydrate antigen of the Streptococcus mutans cell wall. Serotype g carbohydrate was purified from a mutanolysin (M1) enzyme digest (and designated M1g) of S. mutans 6715 cell walls by ion exchange and gel filtration chromatography. M1g carbohydrate was esterified by stearoylization (sM1g), and subsequently coated to sheep erythrocytes (sM1g-SRBC). This coating antigen was then used for enumeration of IgM anti-M1g PFC responses from spleens of either mice or rats immunized with S. mutans 6715 antigen. Good splenic IgM anti-M1g PFC responses were seen in either mice or rats given S. mutans whole cells or cell walls, while cell wall lysates or M1g were lowly immunogenic. Of interest was the finding that sM1g induced good IgM anti-M1g PFC responses in mice and in murine spleen cell cultures, in vitro. This study describes a method for assessment of individual antibody-producing cells to a major S. mutans cell wall determinant which should facilitate studies directed to determine mechanisms involved in the induction of immune responses to this important bacterium.

von Willebrand Factor A domain-related protein, a novel microneme protein of the malaria ookinete highly conserved throughout Plasmodium parasites.

The mosquito-invasive form of the malarial parasite, the ookinete, develops numerous secretory organelles, called micronemes, in the apical cytoplasm. Micronemal proteins are thought to be secreted during midgut invasion and to play a crucial role in attachment and motility of the ookinete. We found a novel ookinete micronemal protein of rodent malarial parasite Plasmodium berghei, named P. berghei von Willebrand factor A domain-related protein (PbWARP), and report it here as a putative soluble adhesive protein of the ookinete. The PbWARP gene contained a single open reading frame encoding a putative secretory protein of 303 amino acids, with a von Willebrand factor type A module-like domain as a main component. Western blot analysis demonstrated that PbWARP was firstly produced 12 h after fertilization by maturing ookinetes as SDS-resistant complexes. Recombinant PbWARP produced with a baculovirus system also formed SDS-resistant high-order oligomers. Immuno-electron microscopic studies showed that PbWARP was randomly distributed in the micronemes. PbWARP homologues also exist in human malarial parasites, Plasmodium falciparum and Plasmodium vivax. Highly conserved primary structures of PbWARP homologues among these phylogenetically distant Plasmodium species suggest their functional significance and the presence of a common invasion mechanism widely utilized throughout Plasmodium parasites.

The high molecular mass rhoptry protein, RhopH1, is encoded by members of the clag multigene family in Plasmodium falciparum and Plasmodium yoelii.

Malarial merozoite rhoptries contain a high molecular mass protein complex called RhopH. RhopH is composed of three polypeptides, RhopH1, RhopH2, and RhopH3, encoded by distinct genes. Using monoclonal antibody-purified protein complex from both Plasmodium falciparum and Plasmodium yoelii, peptides were obtained by digestion of RhopH1 and their sequence determined either by mass spectrometry or Edman degradation. In both species the genes encoding RhopH1 were identified as members of the cytoadherence linked asexual gene (clag) family. In P. falciparum the family members on chromosome 3 were identified as encoding RhopH1. In P. yoelii two related genes were identified and sequenced. One of the genes, pyrhoph1a, was positively identified as encoding RhopH1 by the peptide analysis and the other gene, pyrhoph1a-p, was at least transcribed. Genes in the clag family present in both parasite species have a number of conserved features. The size and location of the P. yoelii protein complex in the rhoptries was confirmed. The first clag gene identified on chromosome 9 was implicated in cytoadherence, the binding of infected erythrocytes to host endothelial cells; this study shows that other members of the family encode merozoite rhoptry proteins, proteins that may be involved in merozoite-erythrocyte interactions. We propose that the family should be renamed as rhoph1/clag.

The fatty acids of each lipid fraction and their use in providing energy source of the plerocercoid of Spirometra erinacei.

The fatty acid concentration of each lipid fraction of plerocercoids of Spirometra erinacei and the host snake serum was investigated. The major fatty acids of phospholipid of the plerocercoids were C18:1, C18:0 and C16:0, and those of the host snake serum were C16:0, C18:1 and C18:0, in order of amount in both cases. The changes of the fatty acid composition of phospholipid of the plerocercoids when they were incubated in physiological saline at 18 degrees C and at 37 degrees C for 24 h were investigated in both cases. Polyunsaturated fatty acids increased at 18 degrees C, and saturated fatty acids increased at 37 degrees C. Michaelis constants (Km) of beta-hydroxyacyl-CoA dehydrogenase (HAD), NADH: ubiquinone oxidoreductase (complex I) (NADH: ferricyanide reaction) and complex I (NADH: ubiquinone reaction) for NADH were 20.6, 50 and 13.3 microM, respectively. The ATP production in mitochondria of the plerocercoids was accelerated by adding ADP and inhibited by adding such electron transport system inhibitors as rotenone, antimycin A and sodium cyanide. These results suggested that the fatty acids in the plerocercoids played an important role in regulating the fluidity of membrane by changing the composition in membrane lipid corresponding with the change of temperature circumstance. The NADH reduced by HAD might be accepted by the complex I in the electron transport system, and thus the parasites were capable of ATP production in a classical pathway of the oxidative phosphorylation system.

Cell wall preparation consisting of group A carbohydrate and peptidoglycan moieties from Streptococcus pyogenes activates murine B lymphocytes.

Cell walls from Streptococcus pyogenes strain Sv (Group A, M type 3) were lysed with M1 endo-N-acetylmuramidase, and the group A-specific carbohydrate antigen was purified by Sephadex G-100 gel filtration. The initial eluting antigen (M1gA) peak was assessed for mitogenic and polyclonal lymphocyte-activating properties in murine spleen cell cultures. Good mitogenic responses were induced over a broad dose range (1-100 micrograms) with M1gA in both BALB/c and C3H/HeJ splenic cultures. Similar mitogenic responses were induced in nude (nu/nu) and nu/+ splenic cultures, suggesting that M1gA is a B cell mitogen. The M1gA induced anti-trinitrophenyl, anti-sheep erythrocytes, and anti-horse erythrocytes polyclonal plaque-forming cell responses in splenic cell cultures. Studies with purified splenic B cells and M1gA suggest that the mitogenic responses were indeed thymic independent. These studies clearly indicate that native group A carbohydrate antigen is a B cell mitogen and polyclonal B cell activator.

Identification and localization of a soluble antigen, Ag2, of 136 kDa from Plasmodium falciparum in vitro cultures.

The soluble antigens, antigen 2 (Ag2) and antigen 6 (Ag6), were copurified from supernatants of P. falciparum in vitro cultures by affinity chromatography and Fast Protein Liquid Chromatography. Rabbit antibodies to Ag2 were raised and characterized by crossed immunoelectrophoresis. Ag2 appeared as a duplet with molecular masses of 136 and 120 kDa when tested by immunoblotting. Immunoprecipitation experiments on Triton X-100 extracted antigens from synchronized cultures showed that the antigen was synthesized in the schizont stage. Ag2 was located near the surface of schizonts in the parasitophorous vacuole and in clefts in the infected erythrocyte cytoplasma as shown by immunogold electron microscopy.

Immunochemical studies on dextrans. Two distinct alpha 1 linked to 3 specificities of rabbit anti-dextran B1355.

Rabbit anti-dextran B1355 sera prepared by injecting rabbits with Leuconostoc mesenteroides NRRL B1355 were separated on a Sephadex G75 column into two fractions, one binding and the other not binding to the column. Oligosaccharide inhibition of precipitation of the two fractions with dextran B1355 indicated that both fractions had alpha 1 linked to 3 specificity. However, antibodies in the non-binding fraction were shown to be directed against O-alpha-D-glucopyranosyl-(1 linked to 3)-O-alpha-D-glucopyranosyl-(1 linked to 6)-D-glucose, while those in the binding fraction were directed against O-alpha-D-glucopyranosyl-(1 linked to 6)-O-alpha-D-glucopyranosyl-(1 linked to 3)-D-glucose. These results are consistent with the proposal of Bhoopalam et al. (Proc. Soc. Exp. Biol. Med. (1979(=) 161, 430-434) that there are different epitopic groups on this dextran.

Immunochemical studies on dextrans. Cross-reaction of synthetic linear dextrans with rabbit anti-N4 dextran.

Alpha (1 Leads to 6) specific anti-dextran antibody was raised in rabbits by injecting N4 dextran-concanavalin A conjugate, and the interactions of five synthetic linear dextrans (alpha(1 Leads to 6)-D-glucopyranans) with rabbit anti-N4 dextran were studied. The ability of glucans to precipitate antibody depended on their average molecular weight, samples with higher molecular weight precipitating more antibody nitrogen under the same conditions. This phenomenon was shown to be due to solubility of the antigen-antibody complex. Oligosaccharide inhibition assay indicated that the maximum size of the alpha(1 Leads to 6)-specific antibody combining site corresponded to isomaltopentaose. The precipitated antibody class was shown to be IgG immunoglobulin, and it was mostly directed to linear non-terminal glucosidic linkages. Determination of antibody nitrogen and glucan in the precipitates indicated that the ratio of antibody molecule to numbers of glucose residues was 1:16 in the extreme antibody excess region.

Cross-reaction of synthetic alpha-(1----3)-branched glucans with rabbit anti-N4 dextran.

Cross-reactions of four synthetic branched glucans (3-O-alpha-D-glucopyranosyl-(1----6)-alpha-D-glucopyranans: V39, V17, V37, and V32, each containing one unit glucose branches amounting to 11-12%, 33-43%, 50-54%, and 71-100%, respectively) with rabbit anti-N4 dextran were examined. All four samples precipitated antibodies raised in rabbits by injecting N4 dextran-concanavalin A conjugate. The ability of glucans to precipitate antibody depended on the quantity of branches, samples with more branches precipitating less antibody nitrogen under the same conditions. This may indicate an inhibitory effect of the branches on precipitation. Oligosaccharide inhibition assay showed that the precipitation reactions were specific for (1----6)-alpha-D-glucopyranosyl linkages, and the maximum size of the alpha-(1----6)-specific antibody combining site corresponded to isomaltopentaose. Determination of antibody nitrogen and glucan in the precipitates indicated that the ratios of one combining site of antibody to numbers of glucose residues were 1:9 (V39), 1:11 (V17), and 1:16 (V37) in the extreme antibody excess region. A synthetic sample of manno-glucan ((1----6)-alpha-D-glucopyranan containing about 27% of randomly linked 3-O-alpha-D-mannopyranosyl side chains) also reacted with the same antibody.

Preparative use of the analytical column of a sugar autoanalyzer for resolution of gluco-oligosaccharides of the same molecular weight.

A sugar autoanalyzer was used on a preparative scale to resolve a gluco-oligosaccharide mixture. In this way the components of the following mixtures were resolved: O-alpha-D-glucopyranosyl-(1-3)-O-[alpha-D-glucopyranosyl-(1-6)]-D-glucose (1), O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-3)-D-glucose (2) and O-alpha-D-glucopyranosyl-(1-3)-O-alpha-D-glucopyranosyl-(1-6)-D-glucose (3), O-alpha-D-glucopyranosyl-(1-3)-O-alpha-D-glucopyranosyl-(1-4)-D-glucose (4) and O-alpha-D-glucopyranosyl-(1-4)-O-alpha-D-glucopyranosyl-(1-3)-D-glucose (5), and O-alpha-D-glucopyranosyl-(1-2)-O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-6)-D-glucose (6) and O-alpha-D-glucopyranosyl-(1-3)--O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-6)-O-alpha-D-glucopyranosyl-(1-6)-D-glucose (7).

Effects of selected surfactants on purified glucosyltransferases from mutans streptococci and cellular adherence to smooth surfaces.

The inhibitory effect of non-ionic, anionic, cationic and ampholytic surfactants on cellular growth of Streptococcus mutans MT8148 and S. sobrinus 6715, on glucan synthesis by the purified glucosyltransferase (GTase) from these organisms, and on bacterial adherence to glass surfaces was examined in vitro. Cationic surfactants exhibited marked bactericidal activities. Anionic and ampholytic compounds were less strongly bactericidal and non-ionic surfactants produced only slight inhibition of cell growth under the conditions tested. Some non-ionic compounds had no effect on this. Glucan synthesis by GTase from mutans streptococci was inhibited by anionic and cationic surfactants. Among various GTase proteins, insoluble glucan synthesising GTases, i.e., S. mutans CA-GTase and S. sobrinus GTase-I were those most effectively inhibited by these agents. However, it was noted that whereas lower concentrations of cationic surfactants enhanced these GTase activities, higher concentrations of the surfactants were inhibitory. Non-ionic detergents stimulated soluble glucan synthesis from S. mutans CF-GTase and cationic and ampholytic surfactants enhanced or inhibited glucan synthesis depending on the concentrations of the surfactants. Sucrose-dependent cellular adherence of resting cells of mutans streptococci to glass surfaces was inhibited by the addition of surfactants that annulled the GTase activities.

Influence of opioid peptides on the priming action of estrogen on lordosis in ovariectomized rats.

Lordosis in response to male mounting in estrogen-progesterone primed ovariectomized rats was facilitated by beta-endorphin or metenkephalin but inhibited by leu-enkephalin if the peptides were injected into third ventricle at the time of estrogen-priming. It is suggested that opioidergic systems modulate the activation of the estrogen-dependent brain functions that control lordosis.

Naloxone and initial estrogen action to induce lordosis in ovariectomized rats: the effect of a cut between the septum and preoptic area.

The effects of intra-third-ventricular (ITV) injection of naloxone (NLX), an opioid receptor antagonist, on lordosis behavior were studied in ovariectomized female rats given a horizontal half-circle cut located just above the anterior commissure (ARD) and subcutaneously (s.c.) treated with estradiol benzoate (EB) and progesterone (Prog). In ARD-sham control animals, lordosis quotient (LQ) was 78.8 +/- 4.2% (SE,n = 8). LQ (48.3 +/- 7.2%, SE, n = 8) in the ARD-sham rats significantly decreased with the ITV injection of NLX at the time of s.c. EB-priming. In contrast, lordosis reflex in the ARD-operated animals was maximally facilitated (sham versus ARD, P < 0.01). LQ in the ARD-operated rats did not decrease with the ITV injection of NLX at the s.c. EB-priming. The present results suggest that the opioidergic systems modulate an initial phase of estrogen action to induce lordosis and play a part in neural input from the forebrain structures to regulate female sexual receptivity.

Antibacterial activities and release kinetics of a newly developed recoverable controlled agent-release system.

We attempted to develop a resin with a recoverable antibacterial activity based on the desorption/adsorption of a cationic bactericide by the ion-exchange mechanism. The aims of this study were to investigate the release kinetics of the agent and the antibacterial activity of this newly designed resin system. An experimental resin was prepared by the addition of methacrylic acid as a cation-exchanger and a cationic antibacterial agent, cetylpyridinium chloride (CPC), to triethyleneglycol dimethacrylate. The amount of CPC desorbed from the experimental resin into buffer solutions at pH 4-8 was measured. The adsorption of CPC to control resin and re-adsorption of CPC to the experimental resin, which had once desorbed the agent, were also determined. The antibacterial activity of experimental resin against Streptococcus mutans was evaluated, and the relationship between bacterial acid production and antibacterial effect was assessed. The experimental resin desorbed CPC at pH < or = 6, and the amount of agent desorbed increased with increasing acidity. The control resin adsorbed CPC when immersed in CPC aqueous solution at a rate determined by the concentration of the agent and immersion time. The experimental resin, once desorbed CPC, could re-adsorb the bactericide by being exposed to a solution of the agent. Less plaque formed on the experimental resin, and the growth and survival of S. mutans was inhibited in the condition in which acid was produced. These results demonstrate that the resin system proposed was able to desorb and re-adsorb the cationic bactericide by an ion-exchange mechanism and could show an inhibitory effect on S. mutans growth and plaque formation.