Deletion in the genes encoding outer surface proteins OspA and OspB of Borrelia garinii isolated from patients in Japan

We detected the expression of outer surface proteins OspA and OspB, and characterized the genes encoding the two Osps of eight Borrelia garinii isolates from patients in Japan. Six of the eight strains shared a common antigenic epitope in their OspA and/or OspB proteins to monoclonal antibody P3134 against OspB, and were identified to have a conserved carboxyl terminus on their ospA and ospB genes by Southern blot hybridization. One strain, JEM4, did not express OspB protein, which was due to lack of the ospB gene. Gene cloning and sequencing analysis revealed that it had only one osp open reading frame with 819 nucleotides, which was similar to the ospA gene. The deletion of the ospB gene could be explained by a homologous recombination based on the common C-terminal sequences on the ospAB operon.

Genetic diversity of Borrelia burgdorferi sensu lato isolated in far eastern Russia

One-hundred and fifty-seven Borrelia isolated from adult ticks, Ixodes persulcatus, and wild rodents, Clethrionomys rufocanus and Apodemus peninsulae, in the far eastern part of Russia were characterized and identified by restriction fragment length polymorphism (RFLP) of the 5S-23S rRNA intergenic spacer. Some isolates showed unique RFLP patterns and were determined as Borrelia garinii on the basis of a sequence analysis of the intergenic spacer amplicon and reactivity with species-specific monoclonal antibodies (MAbs). 86.5 and 12.7% of the tick isolates, and 74.2 and 12.9% of the rodent isolates were determined as Borrelia garinii and Borrelia afzelii, respectively, but not Borrelia burgdorferi sensu stricto was detected. This finding is similar to the results obtained from Borrelia surveys of I. persulcatus and wild rodents in Hokkaido, Japan.

Excitatory amino acid receptors in the paraventricular hypothalamic nucleus mediate pressor response induced by carotid body chemoreceptor stimulation in rats

In urethane-anesthetized rats with spinal transection, antagonists of excitatory amino acid receptors, P2 purinoceptors and adrenoceptors were microinjected into the paraventricular hypothalamic nucleus (PVN) and their effects on the pressor response evoked by carotid body chemoreceptor stimulation were examined. Microinjections of the non-selective excitatory amino acid antagonist kynurenate, the non-NMDA receptor antagonist CNQX and the NMDA antagonist 2-amino-5-phosphonovalerate (AP5) into the PVN inhibited the chemoreceptor reflex-induced pressor response. The excitatory amino acid agonist L-glutamate injected into the PVN produced an increase in blood pressure. The P2 purinoceptor antagonist suramin did not affect the pressor response and ATP did not affect basal blood pressure. The alpha adrenoceptor antagonist phentolamine, prazosin and yohimbine also inhibited the chemoreceptor-induced pressor response, while the beta antagonist propranolol did not affect it. These findings indicate that excitatory amino acid receptors and alpha adrenoceptors in the PVN are involved in mediating the pressor response induced by carotid body chemoreceptor stimulation in rats.

Characterization of Borrelia garinii isolated from Lyme disease patients in Hokkaido, Japan, by sequence analysis of OspA and OspB genes

The outer surface proteins OspA and OspB genes of clinical Borrelia garinii isolates (JEM1-8) from Hokkaido, Japan were sequenced. One strain, JEM4, has a single ospA gene which is similar to European B. garinii strains PBr (sequence homology value: 94.1%) and T25 (91.2%). Five of the other seven strains exhibit a homologous C-terminus (300 bp) on both ospA and ospB genes (88.7-97.3%). The other two strains seem to be derived from the five strains by ospA or ospB alterations. In a phylogenetic analysis based on ospA, these strains could be classified into B. garinii, but formed independent branches and separated from the typical B. garinii isolates from Europe and Russia.

Relationship between pathogenicity of Coxiella burnetii isolates and gene sequences of the macrophage infectivity potentiator (Cbmip) and sensor-like protein (qrsA)

Coxiella burnetii, the Q fever agent, is an obligate intracellular bacterium and survival in phagolysosomes is an important virulence factor. The present study was performed to determine the relationship between its pathogenicity and genes related to its survival in macrophages, i.e. macrophage infectivity potentiator and Q fever agent regulatory sensor-like protein. The sequence similarity was more than 99% among Japanese, European and American strains, and no relationship was found between pathogenicity in guinea pigs and these genes.

Sexual selection in Japanese macaques II: female mate choice and male-male competition

Mating and reproductive outcomes are the product of the potentially conficting strategies of breeding males and females. In a captive group of Japanese macaques, Macaca fuscata fuscatabehavioural, endocrine and genetic data were combined to assess the independent effects of male-male competition and female mate choice on mating and reproductive success. Males were ranked by social dominance and by their attractivity to females. Computer simulation and logistic regression analyses showed that male attractivity had a stronger effect than male dominance on both mating and reproductive outcome. Although male dominance and attractivity both significantly predicted mating success during fertile periods, only male attractivity significantly predicted actual male reproductive success. These results provide evidence that female mate choice can be a stronger determinant of mating and reproductive outcome in this species when male and female strategies are in conflict. The lack of a consistent correlation between male dominance rank and reproductive success in this species may be accounted for in part by female mate choice of socially subordinate males. Sires who were observed to mate with the mother during her fertile period were more likely to be socially dominant than sires who were not observed to do so. This observation suggests the existence of alternative mating strategies by subordinate males, which may also contribute to the lack of a consistent correlation between male dominance rank and reproductive success in this species.1997The Association for the Study of Animal Behaviour

Sexual selection in Japanese macaques I: female mate choice or male sexual coercion?

Mate choice is defined as a behavioural pattern in one sex which increases the probability of fertile matings with certain members of the opposite sex. The chosen sex may use force, however, to coerce matings from reluctant members of the choosing sex. In a confined group of Japanese macaques, Macaca fuscata fuscatahoused at the Primate Research Institute of Kyoto University, Japan, behavioural and endocrine data were combined to assess the validity of several mate-choice behaviours and the potential influence of sexual coercion. Preliminary evidence was found for both female mate choice of males and male sexual coercion of females. Both female proximity maintenance towards males and male aggression towards females were correlated with an increase in fertile matings. Most male aggression appeared to be the by-product of increased time spent in proximity due to female proximity maintenance, but some male aggression appeared to be sexual coercion. These results are interpreted in light of recent research on male sexual coercion, and a tentative model of mate choice for this species is proposed.1997The Association for the Study of Animal Behaviour

Homogeneity of Borrelia japonica and heterogeneity of Borrelia afzelii and 'Borrelia tanukii' isolated in Japan, determined from ospC gene sequences

Borrelia afzelii, B. japonica, and 'B. tanukii' isolated from various sources and geographical origins in Japan were characterized by restriction fragment length polymorphism (RFLP) analysis and sequencing analysis of the outer surface protein C (OspC) amplicon. B. afzelii and 'B. tanukii' generated variable RFLP patterns and differences in ospC gene sequence were confirmed. In contrast, 26 isolates of B. japonica generated one OspC RFLP type, and sequence similarity between B. japonica ranged from 96.4 to 99.7%. These finding suggests that B. japonica is unique in comparison with other members of B. burgdorferi sensu lato species with respect to homogeneity of the ospC gene.

Glycosphingolipid-binding protein of Borrelia burgdorferi sensu lato

The binding of Borrelia burgdorferi, the causative agent of Lyme disease, to glycosphingolipids present in various types of cells was examined. B. burgdorferi bound specifically to galactosylceramide (GalCer) and glucosylceramide (GlcCer) but not to other glycosphingolipids, as determined by a thin-layer chromatography (TLC) overlay assay. The binding specificity of B. burgdorferi to various glycosphingolipids suggested that the binding receptor in this species is ceramide monohexoside. The levels of binding of B. burgdorferi virulent strain 297 to GlcCer, sulfatide, lactosylceramide, and galactosylgloboside were 56.2, 1.6, 15.9, and 9.7%, respectively, relative to that to GalCer. Virulent low-passage strains of B. burgdorferi were serially subcultured in BSK II medium, and the resultant high-passage strains were not capable of infecting mice and did not induce footpad swelling. The levels of binding of the low-passage strains to GalCer on TLC plates and to CHO-K1 cells in vitro were threefold higher than those of high-passage strains. Binding was not affected by pretreatment of Borrelia with monospecific anti-outer surface protein C (OspC) antiserum. These results indicated that the binding of Borrelia to glycosphingolipid expressed on the cell surface plays an essential role in infection of mammalian hosts. However, OspC was not associated with binding. The necessity of the sugar and N-acyl moieties in GalCer for the binding of Borrelia was shown by a TLC overlay assay using chemically modified GalCer. Furthermore, three proteins, 67-kDa protein, 62-kDa Hsp60, and 41-kDa flagellin, were involved in binding of B. burgdorferi to GalCer, as shown by blotting assay using biotinylated GalCer as a probe.

Identification of rickettsiae isolated in Japan as Coxiella burnetii by 16S rRNA sequencing

The 16S rRNA genes of Japanese Coxiella isolates obtained from various sources and geographical areas were directly sequenced by dideoxynucleotide chain termination methods in which Taq DNA polymerase was used. The levels of sequence similarity among Japanese, European, and American isolates were more than 99%, and the Japanese isolates were identified as Coxiella burnetii, C. burnetii strains isolated worldwide, including Japan, were found to be very similar.

Induction of human IgE synthesis in B cells by a basophilic cell line, KU812

Induction of human IgE synthesis in B cells requires, in addition to IL-4 or IL-13, a second signal provided by CD40 ligand (CD40L) on activated Th2-type CD4+ T cells that do not or weakly express Fas ligand (FasL). Mast cells and basophils also produce IL-4 or IL-13 and express CD40L after immunologic or pharmacologic stimulation, although it is unknown whether these cells express FasL. This study investigated the capacity of KU812 cells, a human basophilic cell line, to produce IL-4 and IL-13, to express CD40L and FasL, and to induce IgE and IgG4 synthesis in human normal B cells. Upon stimulation of KU812 cells with either phorbol myristate acetate (PMA) or ionomycin (Iono), IL-4, but not IL-13, was produced in response to Iono, while IL-13, but not IL-4, was inducible by PMA. Moreover, both the time courses of IL-4 and IL-13 production and their amounts secreted were different; IL-4 production was transient, IL-13 production gradually increased, and IL-13 was heavily secreted as compared with IL-4. The combination of PMA and Iono (PMA/Iono) induced higher production of IL-4 or IL-13 than did Iono or PMA alone. KU812 cell-derived IL-4 and IL-13 had the ability to cause CD23 expression on B cells. PMA/Iono also up-regulated CD40L expression and induced a very low level expression of FasL. KU812 cells that had been activated by PMA/Iono followed by fixation could induce IgE and IgG4 synthesis in B cells in the presence of recombinant IL-4 or IL-13. This contact-dependent induction of IgE was completely abrogated by adding anti-CD40L MoAb or soluble CD40, whereas anti-FasL antibody did not significantly affect IgE production. These results indicate that activated KU812 cells produce biologically active IL-4 and IL-13, express functional CD40L, and exhibit weak induction of FasL, thereby supporting sufficient IgE production by B cells.

Association of natural killer cell activity with serum IgE

Association of natural killer (NK) cell activity (NKCA) or NK cell subsets with total IgE or antigen-specific IgE in serum were studied among 66 healthy non-allergic males. NKCA was determined by using 61Cr release assay and NK subsets were counted usings surface antigens (CD16, CD57) in peripheral blood mononuclear cells. NKCA was associated mainly with the frequency of a CD16+,CD57- subset. When the subjects were classified into three groups according to total IgE values in serum (grade 0: IgE < 10 IU/ml; grade 1: IgE 10-400 IU/ml; grade 2: IgE > 400 IU/ml), one-way analysis of variance of NKCA showed that the grades of total IgE were significantly associated with increasing NKCA. In addition, NKCA in the grade 0 group was significantly lower than that in the grade 2 group and than a mixture of grade 1 group and grade 2 group. A similar finding was not observed between NKCA and RAST for specific IgE against mites. Therefore, NKCA may be related to total IgE level in serum.

A case of Lyme disease diagnosed serologically

A 57-year-old Japanese male developed erythema migrans, arthralgia, and neurological symptoms after mountain climbing in Nagano Prefecture. On ELISA, his serum reacted to Borrelia isolated from various sources. The patient's serum reacted with a 41 kilodalton protein which was reactive with monoclonal antibody H9724 specific to flagellin of Borrelia on Western blotting. He recovered after taking minocycline 200 mg daily for 2 weeks.

Possible role of nuclear factor-kappa B activity in germline C epsilon transcription in a human Burkitt lymphoma B cell line

Nuclear factor-kappa B (NF-kappa B) plays a broad role in gene regulation, but it is not evident whether NF-kappa B acts as a messenger system for germline C epsilon transcription. We report here that the signaling cascade triggered by interleukin-4 (IL-4) or anti-CD40 monoclonal antibody (mAb) participates in NF-kappa B activation responsible for germline C epsilon transcription in a human Burkitt lymphoma B cell line, DND39. Both IL-4 and anti-CD40 mAb induced activation of phosphatidylinositol 3-kinase (PI3-kinase), translocation of a zeta isoform of protein kinase C, and nuclear expression of NF-kappa B. All such events were abrogated by treatment with LY294002, a specific inhibitor of PI3-kinase. In addition, N-acetyl-L-cysteine (NAC), a potent antioxidant, decreased NF-kappa B activation caused by IL-4, anti-CD40 mAb, or their combination. NAC was also effective in diminishing germline C epsilon transcription, and its potency was higher in cultures costimulated with IL-4 and anti-CD40 mAb than in those stimulated with IL-4 alone. These results indicate that IL-4 and ligation of CD40 induce NF-kappa B expression via at least a mechanism dependent on the PI3-kinase pathway and suggest that NF-kappa B sensitive to NAC may play a role in regulating germline C epsilon transcription.

Consensus sequence on the genes encoding the major outer surface proteins (OspA and OspB) of Borrelia garinii isolate

Japanese Lyme borrelias classified as ribotype IV is predominant among isolates derived from clinical specimens, reservoir rodents and Ixodes persulcatus ticks, and has been characterized as Borrelia garinii. These B. garinii isolates have antigenic and genetic features apparently different from North American, European and other Asian isolates, especially in major outer surface proteins A (OspA) and B (OspB). In this study, we cloned and sequenced the genes encoding OspA and OspB from B. garinii strain FujiP2 (ribotype IV strain) isolated from I. persulcatus in Shizuoka, Japan. A sequence analysis revealed significant differences to the previously published sequences of ospA and ospB of B. burgdorferi sensu lato. The open reading frames of ospA and ospB consist of 822 and 888 nucleotides corresponding to the proteins of 273 and 295 amino acids, with molecular weights of 29,643 and 31,786 daltons, respectively. The most interesting finding is that the two osp genes share a consensus 282 bp sequence in their carboxy-terminal portions and that the ospB gene is flanked by a 282 bp-long direct repeat sequence. The deduced amino-acid (aa) sequences of OspA and OspB of strain FujiP2 showed 60.1% homology, and have overall similarities of 70.5%, 70.3% and 75.6% to OspAB proteins of B. burgdorferi sensu stricto strain B31, Borrelia afzelii strain ACA1 and Borrelia garinii strain Ip90, respectively.

PCR-restriction fragment length polymorphism analysis of the ospC gene for detection of mixed culture and for epidemiological typing of Borrelia burgdorferi sensu stricto

Restriction fragment length polymorphism (RFLP) analysis of the outer surface protein C (ospC) gene amplicon was used for rapid screening for genetic variability within Borrelia burgdorferi sensu stricto species and for detection of multiple borreliae in culture. Primers for the ospC gene amplified a fragment of about 600 bp from Borrelia cultures. After cleavage of the amplified products by MboI and DraI, eight different RFLP types were found among 13 B. burgdorferi sensu stricto strains from various sources and geographical areas, and three RFLP types were found among 10 representative isolates from skin biopsy specimens taken from patients residing on the eastern end of Long Island, New York (B. W. Berger, R. C. Johnson, C. Kodner, and L. Coleman, J. Clin. Microbiol. 30:359-361, 1992). These results suggested that the DNA organization of B. burgdorferi sensu stricto is heterogeneous not only globally but also within a localized geographical area and that the ospC-based typing approach could differentiate the B. burgdorferi sensu stricto. From the results obtained using mixed cultures of two different RFLP types of B. burgdorferi sensu stricto, contamination of at least 0.5% of different types of Borrelia cells in culture could be detected. This method could detect a multiple-B. burgdorferi sensu stricto infection in the bladders of mice experimentally infected with two different RFLP type strains. The present study showed that RFLP analysis of ospC-PCR products is a reliable method for epidemiological typing of B. burgdorferi sensu stricto and could be used for rapid detection of mixed Borrelia culture and multiple B. burgdorferi sensu stricto infections in animals, ticks, and patients.

Allergenicity of acid protease secreted by Candida albicans

We have previously reported the cases of Candida albicans (C. alb) acid protease (CAAP)-induced atopic asthma. In this study, the allergenicity of the released enzyme CAAP was examined among asthmatic patients with positive immediate skin response to crude C. alb antigen. Among 49 patients with positive skin response to crude C. alb, anti-crude C. alb IgE antibodies were detected in 40 and anti-CAAP IgE antibodies were detected in 18. Moreover, anticrude C. alb IgE antibodies were detected in all of the patients in whom anti-CAAP IgE antibodies were detected. No correlations between IgG antibodies to both antigens or between IgE and IgG antibodies to CAAP were observed. CAAP induced significant T-cell proliferation in 20/28 patients showing positive T-cell proliferation response to crude C. alb antigen. Most of the patients showing positive conjunctival response to crude C. alb antigen also showed positive response to CAAP. Most of the patients showing high levels of serum IgE antibody and positive histamine-release response of peripheral blood leukocytes to CAAP showed positive conjunctival response. The results indicate that CAAP is an important allergen in C. alb-related mucosal allergy.

Involvement of nuclear factor-kappa B activation in IgE synthesis in human B cells

Nuclear factor-kappa B (NF-kappa B) is a transcription factor that binds to the consensus DNA sequence in the cis-acting elements of various genes. Although NF-kappa B activates the expression of many genes involved in immune and inflammatory responses, little is known about the role of NF-kappa B activation in the induction of IgE synthesis in human B cells. Therefore we first examined the participation of NF-kappa B in germline C epsilon transcription in a human Burkitt lymphoma B cell line, DND39. Stimulation of DND39 cells with IL-4 or anti-CD40 monoclonal antibody (mAb) activated phosphatidylinositol 3-kinase and subsequently induced nuclear expression of NF-kappa B, which was identified by electrophoretic mobility shift assays. n-Acetyl-L-cysteine (NAC), a potent antioxidant, blocked NF-kappa B activation caused by IL-4 and by anti-CD40 mAb. Although inhibition of IL-4-driven germline C epsilon transcription by NAC was not sufficient, the agent remarkably diminished anti-CD40 mAb-mediated up-regulation of germline C epsilon transcription. Second, we studied the effect of NAC on IgE synthesis in human normal B cells costimulated with IL-4 and anti-CD40 mAb. NAC was effective in inhibiting mature C epsilon transcription and IgE synthesis in the T cell-independent culture system. However, NAC did not significantly affect the spontaneous production of IgE by atopic B cells. These results indicate that NF-kappa B activity is commonly inducible in DND39 cells by IL-4 and anti-CD40 mAb and suggest that NF-kappa B sensitive to NAC may play a role in regulating IgE synthesis in B cells.

Prevalence of Lyme disease spirochetes in Ixodes persulcatus and wild rodents in far eastern Russia

Borrelia spirochetes were isolated from the adult ixodid tick (Ixodes persulcatus) in three areas of far eastern Russia, namely, Khabarovsk, Vladivostok, and Yuzhno-Sakhalinsk. Borrelia infective rates of ticks in those areas were 24.5, 41.4, and 25.1%, respectively (total rate was 26.6%). Spirochetes were also isolated from the tissues of small mammals captured at Khabarovsk (infective rate was 20.8%). Samples were classified by rRNA gene restriction fragment length polymorphism (RFLP) analysis. The isolated spirochetes from ticks were classified mainly RFLP ribotype group IV (B. garinii), followed by groups II (B. garinii), III (B. afzelii), and V (B. garinii), showing that B. garinii is a dominant species among them. Both B. garinii and B. afzelii were also found in rodents, and multiple infections with those two species were observed in some rodents. B. burgdorferi sensu stricto (group I) was not isolated from either ticks or rodents.

Characterization of Borrelia spp. isolated from the tick, Ixodes tanuki and small rodents in Japan

Spirochetes were isolated from the tick, Ixodes tanuki, as well as wood mice (Apodemus speciosus) and voles (Clethrionomys rufocanus and Eothenomys smithii), caught in Fukui, Tokushima, and Hokkaido, Japan, from 1991 to 1993. Spirochetes were characterized on the basis of protein profiles, reactivities with monoclonal antibodies (mAbs), Outer surface protein A gene (ospA) and Outer surface protein B gene (ospB) amplification analysis, rRNA gene and flagellin gene restriction fragment length polymorphism (RFLP) analysis, and DNA homology values. Protein profiles of all isolates were homologous and reacted with mAb to OspA, OspB, OspC, flagellin, and heat shock protein 60. The primer reactivity to ospA and ospB were different from those of Borrelia burgdorferi sensu stricto, B. afzelii, B. japonica, and B. garinii. Based on the DNA/DNA homology value and RFLP analysis of rRNA and flagellin gene, these Borrelia sp. isolates are a new group of B. burgdorferi sensu lato. The isolates from ticks and the host rodents were identical in these assays. We propose that these Borrelia sp. are adapted to I. tanuki and are maintained in these field rodents.

Antibody-producing effects in mice by synthetic immunoactive lipopeptides with the conjugated amino acid sequence of gp120 in human immunodeficiency virus

To induce peptide-specific antibodies in mice, as a model for vaccination against human immunodeficiency virus (HIV), lipopeptide analogs conjugated with three repeating units (KAB-112; designated as gp120-peptide) of a part (Gly-Pro-Gly-Arg-Ala-Phe) of the amino acid sequences of the V3 loop region in gp120 of HIV were synthesized. The mitogenicity, production of nitric oxide (NO) and induction of peptide-specific antibodies in mice by synthetic lipopeptides were examined. Compounds, KAB-8 (diacylglycerol-tetrapeptide having a part of the amino acid sequence in Escherichia coli), KAB-116 (diacylglycerol-cysteine), KAB-117 (diacylglycerol with gp120-peptide) and KAB-121 (KAB-8 with gp120-peptide) were capable of increasing significantly the incorporation of [3H]thymidine into splenocytes of C3H/He mice at concentrations ranging from 12.5 to 100 microM, but KAB-112 (gp120-peptide) and KAB-115 (monoacylglycerol with gp120-peptide) did not show such activity. The compounds, KAB-8, KAB-117 and 121, exhibited NO production in murine macrophages. When 50 nmol of these compounds was administered intraperitoneally into BALB/c mice on days 0, 16 and 46, the peptide-specific antibody titers in their sera produced by each compound were determined with ELISA. The sera of KAB-117 and KAB-121, which were obtained on days 14, 30, 42, 57 and 70, had a higher titer than that of KAB-112 and KAB-115, suggesting that the diacylglycerol derivative enhance the production of the peptide-specific antibodies.

Characterization of Borrelia sp. isolated from Ixodes tanuki, I. turdus, and I. columnae in Japan by restriction fragment length polymorphism of rrf (5S)-rrl (23S) intergenic spacer amplicons

Borrelia isolated from various sources in Japan, including rare species of ixodid ticks, Ixodes tanuki, I. turdus, and I. columnae, were characterized by restriction fragment length polymorphism analysis and sequencing analysis of the 5S-23S rRNA intergenic spacer amplicon. Borrelia sp. isolated from I. tanuki, I. turdus and I. columnae generated restriction fragment length polymorphism patterns different from those of known B. burgdorferi sensu lato isolates previously reported. Furthermore, some B. afzelii and B. garinii isolated in Japan showed unique RFLP patterns which were not observed among European B. afzelii and B. garinii.

Comparison of OspA serotypes for Borrelia burgdorferi sensu lato from Japan, Europe and North America

Sixty-one Borrelia burgdorferi sensu lato strains from various sources (ticks, human, and wild animals) in Japan and two strains from ticks in Far Eastern Russia were classified on the basis of reactivity with 16 monoclonal antibodies (mAb) to outer surface protein A (OspA) and by DNA-DNA hybridization assay. Eleven OspA serotypes (J1 to J11) were recognized among the Japanese and the Far East Russian isolates (serotypes J1 to J9 were identified as B. garinii, serotype J10 was identified as B. afzelii, and serotype J11 corresponded to B. japonica), whereas 7 OspA serotypes for North American and European isolates previously reported (Bettina Wilske et al, J. Clin. Microbiol. 31:340-350,1993) were not observed except for OspA serotype 2 which showed identical reactivity with OspA serotype J10. This finding provides helpful information for understanding the geographical distribution of Lyme disease borrelia and the development of vaccine and diagnostic tests.

IN CONCLUSION

1.B. burgdorferi sensu stricto has not been observed in Japan, 2. Japanese B. afzelii isolates are closely related to those from Europe, 3. B. garinii isolates from Japan are highly heterogeneous and apparently different from European B. garinii isolates.

Inhibition of basophil histamine release by a haptenic peptide mixture prepared by chymotryptic hydrolysis of wheat flour

For application to the treatment of wheat-sensitive allergy, we developed a practical method for producing a haptenic peptide mixture, and evaluated its haptenic properties. Wheat flour was hydrolyzed with chymotrypsin to obtain a hydrolysate, and the diffusible fraction from the hydrolysate was subjected to gel-filtration. The resulting oligopeptide fraction could bind to wheat-specific IgE antibodies in the serum of patients allergic to wheat. Since this peptide mixture did not induce histamine release from basophils in these patients, it was concluded that the peptide mixture was composed of monovalent haptens. Histamine release from antigenstimulated basophils was almost completely inhibited when the basophils were preincubated with the haptenic peptide mixture. These results suggest that this haptenic peptide mixture can regulate the allergenic reaction in an epitope-specific manner.

Presence of common antigenic epitope in outer surface protein (Osp) A and OspB of Japanese isolates identified as Borrelia garinii

Japanese Borrelia strains FujiP2, AP83, NT24, NT29 and HT2 which had a 31-kilodalton protein non-reactive with monoclonal antibody (MAb) H5332 to outer surface protein A (OspA) were identified as B. garinii by the DNA hybridization method. MAb P3134 raised to strain NT24 reacted with OspA and the OspB-ranging protein of these isolates and cross-reacted with the OspB-ranging protein of some other isolates. Since the reactive protein was extracted by the Triton X-114 phase partitioning method, the MAb recognized the common epitope present in OspA and OspB. To our knowledge, this is the first report of an MAb reactive to both OspA and OspB.

Evidence for a role of phosphatidylinositol 3-kinase in IL-4-induced germline C epsilon transcription

Association of interleukin-4 receptor (IL-4R) with phosphatidylinositol 3-kinase (PI3-kinase) has been demonstrated as the proximal event of IL-4 signaling. We investigated the role of this enzyme in the IL-4 signaling pathway in a human Burkitt lymphoma B cell line, DND39, that expresses germline C epsilon transcripts in response to IL-4. Stimulation of DND39 cells with IL-4 resulted in an accumulation of PI-3-monophosphate as well as a decrease of PI-4,5-bisphosphate, which were abrogated by wortmannin, a potent inhibitor of PI3-kinase. Activation of PI3-kinase was further confirmed by the finding that IL-4 caused an increase in PI3-kinase activity coimmunoprecipitated with anti-IL-4R and with anti-JAK3 kinase antibodies. As a possible downstream event of PI3-kinase activation, the translocation of a zeta isoform of protein kinase C (PKC) from the cytosol to the membrane fraction was observed after IL-4 stimulation, and wortmannin also suppressed this translocation. Moreover, IL-4-induced expression of germline C epsilon transcription was inhibited not only by wortmannin, but also by a PKC inhibitor, K252a. These results suggest that the signaling pathway involving PI3-kinase and PKC zeta plays an important role in induction of germline C epsilon transcription in DND39 cells by IL-4.

Protective activity of rabbit polyclonal anti-idiotype antibody against Leptospira interrogans infection in hamsters

We prepared an anti-idiotype (Id) antibody against leptospirosis. Serum from rabbit immunized with monoclonal antibody (MAb) LW2, which reacted to the main protective antigen prepared from Leptospira interrogans serovar lai, inhibited agglutination of the organism by MAb LW2. The immune rabbit serum was applied to a column coupled with normal mouse IgG as a ligand (first column), and the unbound fraction eluted was applied to a column coupled with MAb LW2 as a ligand (second column). The bound fraction (anti-Id antibody) eluted from the second column inhibited the binding of MAb LW2 to sonicated leptospiral cells in ELISA. Mice produced antibodies against Leptospira by intraperitoneal immunization with the anti-Id antibody at doses of 2 mu g/mouse or more. Hamsters were protected by immunization with the anti-Id antibody at doses of 2 and 20 mu g/hamster from the lethal infection of Leptospira. This is the first report concerning the use of an anti-Id antibody against leptospirosis.

Immunochemical characteristics and localization on cells of protective antigen (PAg) prepared from Leptospira interrogans serovar lai

Immuno-electron microscopic methods revealed that the protective antigen (PAg) of Leptospira interrogans serovar lai exists on the outer envelope sheathing the leptospiral cell body. PAg lost its protective activity after treatment by hydrolysis with 2 M formic acid at 100 C for 2 hr, or oxidation with periodate at 4 C for 40 hr. The antigenic oligosaccharide fraction was further purified from the hydrolyzed PAg by immunoaffinity column coupled with protective monoclonal antibody, LW2, and by gel filtration of HPLC. The antigenic oligosaccharide fraction contained two unknown sugars and 4-O-methylmannose (molar ratio 3:5:1). These findings suggested that these sugars are components of an antigenic determinant contributing to the protective immunity against serovar lai infection.

[A case of Lyme borreliosis which was suspected to be caused by Borrelia japonica infection in Shizuoka, Japan]

We report a case of Lyme borreliosis (Lyme disease) found in Shizuoka City, Japan which was suspected to be caused by Borrelia japonica infection. A 8-year-old female was bitten on her head by a tick at a camping ground, near Tamagawa, Shizuoka. The tick was removed by the patient and was discarded before species identification. After one week, lymph node swelling with tenderness developed on her left neck. She consulted a local pediatrician and was suspected to have upper respiratory infection. As oral antibiotic, cefaclor was not effective, the patient was referred to us. The patient's serum showed positive reaction with Lyme Borreliosis ELISA kit (Dakopatts, Denmark) using Borrelia burgdorferi flagellum as antigen. The serum also gave positive results with home-made ELISA to B. japonica strain IKA2, which was isolated from I. ovatus, but not with other borrelial strain isolated in the United States, Europe, and from I. persulcatus and wild rodent in Japan. In western blotting, the serum reacted with flagellin and outer surface protein A (OspA) of B. japonica. We diagnosed her as Lyme disease and got a successful result with oral penicillin, sultamicillin. From a result of our field tick survey, we have not collected I. persulcatus around the area where the patient had a tick bite. These findings indicated that Lyme disease was caused by B. japonica infection with I. ovatus bite.

A major wheat allergen has a Gln-Gln-Gln-Pro-Pro motif identified as an IgE-binding epitope

The minimum primary structure of the IgE-binding epitope in wheat gluten was determined as Gln-Gln-Gln-Pro-Pro. The N-terminal glutamine and the two proline residues were essential for epitopic function. The occurrence of the second glutamine residue and acetylation of the N-terminal amino group were found to exert some auxiliary functions, whereas only a lesser contribution was expected for the third glutamine residue. It has also been confirmed that acetyl-Gln-Gln-Gln-Pro-Pro bound to wheat-specific IgE antibodies in the sera of patients allergic to wheat, although it did not induce histamine release from the basophils of these patients. Taken together, we concluded that the Gln-Gln-Gln-Pro-Pro motif constituted an IgE-binding rather than immunogenic epitope and also that acetyl-Gln-Gln-Gln-Pro-Pro might act as a hapten capable of binding to specific IgE molecules. The possibility exists that this peptide will have practical application to therapy for or prevention of wheat-sensitive allergy.

Species-specific measurement of the second group of Dermatophagoides mite allergens, Der p 2 and Der f 2, using a monoclonal antibody-based ELISA

BACKGROUND

The group 2 Dermatophagoides mite allergens, Der p 2 and Der f 2, were known to be highly crossreactive, and previous assays to measure Der p 2 and Der f 2 were not species-specific.

OBJECTIVE

The aim of this study was to develop a monoclonal antibody-based ELISA (MoAb-ELISA) to species-specifically measure Der p 2 and Der f 2.

METHODS

The MoAb-ELISA for Der p 2 and Der f 2 was performed using species-specific MoAbs for Der p 2 and Der f 2 and a biotinylated second MoAb which recognized a common epitope on both Der p 2 and Der f 2.

RESULTS

The assay was highly species-specific, reproducible and sensitive. Thirty-two house dust samples were assayed by the MoAb-ELISA for Der p 2 and Der f 2 and by a previously reported radioimmunoassay for Der 2 with rabbit anti-Der 2 antibodies. The summed values for Der p 2 and Der f 2 by the MoAb-ELISA demonstrated a good correlation with the Der 2 values using the radioimmunoassay (r = 0.978). Furthermore, the proportion of the Der p 2 level in the total Der 2 level (Der p 2 divided by Der p 2 plus Der f 2) correlated well with that of the D. pteronyssinus mite number to the total Dermatophagoides mite number identified by species (r = 0.970).

CONCLUSION

The MoAb-ELISA for Der p 2 and Der f 2, as well as that of Der p 1 and Der f 1, will be useful for the standardization of mite extracts and for the assessments of mite allergen exposure.

A new assay system detecting antibody production and delayed-type hypersensitivity responses to trinitrophenyl hapten in an individual mouse

A new assay system detecting antibody production and delayed-type hypersensitivity (DTH) responses to trinitrophenyl hapten in an individual mouse (AS-DAD) was established. BALB/c mice were immunized intraperitoneally with varying amounts of 2,4,6-trinitrophenylated sheep red blood cells (TNP-SRBC) on day 0. Venous blood was collected on days 2, 4, 6, 8 and 10. Levels of anti-TNP IgM and IgG serum were assayed by enzyme-linked immunosorbent assay (ELISA). After series of bleeding the mice were challenged with 2,4,6-trinitrobenzene sulfonic acid (TNBS) solution in the footpad on day 14. Footpad swelling was measured 24 or 48 h after the challenge. Peak responses of the anti-TNP IgM and IgG production were detected 4 or 6 days after the immunization with 10(9) TNP-SRBC. Maximum DTH response was also observed with 10(9) TNP-SRBC 24 h after the challenge on day 14. The antibody and DTH responses were also induced in other normal inbred strains such as C3H/He and DBA/1 but not BALB/c nu/nu mice. To evaluate AS-DAD in immunopharmacological studies, various immunomodulating agents were examined in BALB/c mice by subcutaneous administration on days 0, 1, 2 and 3. Cyclosporin or cyclophosphamide at 100 mg/kg/day completely inhibited not only the anti-TNP IgM and IgG production but also the TNP-specific DTH response. Prednisolone at 0.5 mg/kg/day had no significant effect on the IgM and IgG production, whereas it inhibited the TNP-specific DTH response. Interestingly, histamine-added mouse gamma-globulin at 150 MG/kg/day clearly enhanced the anti-TNP IgM and IgG production, while it showed a suppressive effect on the TNP-specific DTH response. Levamisole at 5.0 mg/KG/day showed suppressive effects on the anti-TNP IgG production without affecting the IgM production and the DTH response. These results suggest that AS-DAD is useful for evaluating the immunopharmacological action of various agents.

Comparison of the biological activity of synthetic N-acylated asparagine or serine linked monosaccharide lipid A analogs

The mitogenicity, lethal toxicity, induction of tumor necrosis factor (TNF), production of nitric oxide (NO) and antitumor activity against Meth A fibrosarcoma by chemically synthesized N-acylated asparagine-linked (A-701, A-702 and A-703) or N-acylated serine-linked (A-607) nonphosphorylated acylglucosamine and 4-0-phosphorylated acylglucosamine (A-103) derived lipid A analogs were determined. compound A-607 (with tetradecanoyl and (R)-3-tetradecanoyloxytetradecanoyl at the C-2 and C-3 positions) induced a significant incorporation of 3H-thymidine into splenocytes of C3H/He mice at concentrations ranging from 3.13 to 50 microM, but the mitogenic activity of A-701 (2-N-acetylglucosamine), A-702 (tetradecanoyl at the C-2), and A-703 (with (R)-tetradecanoyloxytetradecanoyl and tetradecanoyl at the C-2 and C-3) was very weak. The lethality of A-703 and A-103 (with (R)-3-tetradecanoyloxytetradecanoyl at the C-2 and C-3) was weaker than that of A-607 at doses of 300 and 750 nmol/kg in C57BL/6 mice loaded with D-galactosamine. Peritoneal macrophages, stimulated with A-701-A-703, caused production of TNF which induce L929 cell lysis in vitro, and A-703 showed a high production of TNF. The compounds, except for A-607, exhibited little NO production by macrophages, but did induce the NO production in the presence of interferon gamma. Induction of TNF and NO inducible activity by A-703 was lower than that of A-607. A-703, A-607 and A-103 showed antitumor activity against Meth A fibrosarcoma in BALB/c mice. When A-703 or A-103 with muramyl dipeptide was administered, A-703 failed to show combined effects, but A-103 did. We concluded from these findings that the biological potency of asparagine compounds appears to be placed between serine- and amino-free compounds.

Reservoir competence of the vole, Clethrionomys rufocanus bedfordiae, for Borrelia garinii or Borrelia afzelii

In autumn of 1994 and spring of 1995, we examined Borrelia infection among Microtinae voles, Clethrionomys rufocanus bedfordiae, in Hokkaido, Japan. In BSK culturing of the earlobe tissues of 45 C. rufocanus bedfordiae captured, twelve rodents were positive for Borrelia. Eight isolates were used for the polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) analysis. According to the results, these isolates were classified into B. garinii or B. afzelii. It is considered that a common vole, C. rufocanus bedfordiae, plays a significant role in the transmission and maintenance of B. garinii and B. afzelii, similar to the role of Apodemus speciosus mice.

Functional significance of IL-4 receptor on B cells in IL-4-induced human IgE production

IL-4 with the IgE-inducing activity is shown to upregulate the expression of IL-4 receptor (IL-4R) on lymphocytes. Antisense strategy was used that aimed at investigating the significance of IL-4-induced upregulation of IL-4R on B cells in human IgE production. When an antisense phosphorothioate oligodeoxynucleotide to IL-4R (S-oligo 1) was added to B cells together with IL-4, the agent selectively abrogated the upregulation of IL-4R without affecting its constitutive level expression. Moreover, S-oligo 1 had a suppressive effect on the T-cell-independent synthesis of IgE by B cells costimulated with IL-4 and anti-CD40 antibody. This suppression was accompanied by inhibition of mature but not germline C epsilon transcription. These findings indicate that constitutively expressed IL-4R provides a signal or signals responsible for the induction of germline C epsilon transcription and suggest that IL-4R upregulation may be required for the subsequent class switch recombination that leads to mature C epsilon transcription and IgE synthesis. The IL-4R signal transduction mechanism underlying germline C epsilon transcription was also analyzed in a human Burkitt lymphoma B-cell line, DND39. Induction of germline C epsilon transcripts in DND39 cells by IL-4 required at least two distinct signaling cascades. One was mediated by enhancement of tyrosine phosphorylation of a 57 kd protein associated with phospholipase C-gamma 1 (PLC-gamma 1) that resulted in PLC-gamma 1 activation, inositol lipid hydrolysis, and protein kinase C delta translocation. The other was dependent on phosphatidylinositol 3-kinase, whose activation induced protein kinase C zeta translocation. In fact, kinase inhibitors such as herbimycin A, K-252a, and wortmannin were effective in inhibiting IL-4-induced germline C epsilon transcription. Therefore, in addition to activation of protein tyrosine kinases, coordinated actions of PLC-gamma 1 and phosphatidylinositol 3-kinase may be involved in IL-4-driven germline C epsilon transcription in DND39 cells.

In vitro and in vivo antibiotic susceptibility of Lyme disease Borrelia isolated from the ixodid tick in Japan

Antimicrobial susceptibility of the Lyme disease Borrelia, strain HP1 vi, isolated from the tick ixodes persulcatus in Hokkaido, Japan, was determined in vitro and in vivo. A broth dilution technique was used to determine the minimum inhibitory concentrations (MICs) and minimum borreliacidal concentrations (MBCs) of five antimicrobial agents. Strain HP1 vi was most susceptible to minocycline (MBC, 0.2 micrograms/ml). The other antimicrobial agents tested, aspoxicillin, cefmetazole sodium, imipenem cilastatin sodium, and panipenem betamipron, had higher MBCs of 12.5 micrograms/ml, 25 micrograms/ml, > 25 micrograms/ml, and > 25 micrograms/ml, respectively. In vivo antibiotic susceptibility study using a ddY mouse model demonstrated that minocycline and amoxicillin were effective; minocycline had a lower 50% effective dose (ED50) value (6.25 mg/kg) than amoxicillin (30 mg/kg).

Rapid and sensitive PCR detection of Vibrio trachuri pathogenic to Japanese horse mackerel (Trachurus japonicus)

A polymerase chain reaction (PCR) method was performed for rapid and sensitive detection of pathogenic Vibrio trachuri isolated from cultured Japanese horse mackerel. A set of primers was selected from the base sequence of the Pst I fragment of T9210 chromosomal DNA and used for PCR detection of T9210. This PCR specifically amplified the DNAs from V. trachuri T9210, T9213, and T9216 but not of those other bacterial strains. PCR using a Pst I-1 primer set made it possible to detect 100 fg of T9210 DNA. The PCR method reported here may be useful for detection and identification of V. trachuri pathogenic to Japanese horse mackerel.

Neurotropin inhibits accumulation of eosinophils induced by allergen through the suppression of sensitized T-cells

A non-protein extract isolated from the inflamed dermis of rabbits inoculated with vaccinia virus (Neurotropin) has been clinically used in Japan as an analgesic and anti-allergic drug. To clarify its anti-allergic mechanism, the effect of Neurotropin on eosinophil accumulation induced by ragweed pollen extract or platelet-activating factor (PAF) was examined in BALB/c mice. Neurotropin inhibited the T-cell-dependent accumulation of eosinophils induced by allergen in a dose-dependent manner when administered during sensitization. However, Neurotropin was unable to inhibit the T-cell-independent accumulation of eosinophils induced by PAF. A T-cell transfer experiment was performed to address the inhibitory mechanism. A marked accumulation of eosinophils was observed when recipients were injected i.p. with allergen and Nylon wool column-passed splenic T-cells from the sensitized donor mice. However, significant accumulation of eosinophils was not observed when sensitized donor mice were administered with Neurotropin but not saline. Taken together, these results suggest that Neurotropin inhibits the accumulation of eosinophils induced by allergen via the suppression of sensitized T-cell induction, or alternatively by interfering with T-cell function.

Vibrio trachuri sp. nov., a new species isolated from diseased Japanese horse mackerel

A new species, Vibrio trachuri sp. nov., was isolated from the cultured Japanese horse mackerel (Trachurus japonicus). These Vibrio were Gram negative, motile rods and formed yellow colonies on BTB teepol and TCBS plate, turned TSI medium to yellow and was sensitive to 150 microM O/129 (2,4-diamino-6,7-diisopropyl pteridine phosphate) like Listonella anguillarum which has been described as Vibrio anguillarum. However, the results of VP test and decarboxylation of lysine or dihydrolation of arginine suggested that these Vibrio are rather closely related to V. parahaemolyticus. DNA similarity determined by the microplate hybridization technique revealed that these Vibrio are genetically quite distant from Listonella anguillarum or V. parahaemolyticus and rather close to V. harveyi, although there was no Vibrio species which had more than 70% similarity value. From these results we propose to nominate Vibrio trachuri sp. nov. for this new Vibrio species.

Inhibition of IL-4 receptor up-regulation on B cells by antisense oligodeoxynucleotide suppresses IL-4-induced human IgE production

IL-4 is shown to up-regulate its own receptor (IL-4R) on human lymphocytes, but the functional significance of up-regulated IL-4R is not clear regarding IgE production. This study investigated the possible role of IL-4-induced up-regulation of IL-4R on B cells in the induction of human IgE synthesis by means of antisense strategy. Among three antisense oligodeoxynucleotides designed against the downstream of translation initiation site of IL-4R cDNA, S-oligo 1, complementary to nucleotide 1-24, showed the strongest inhibition of the constitutive expression of IL-4R on Daudi cells. Addition of S-oligo 1 together with IL-4 also decreased the up-regulated but not constitutive levels of IL-4R on peripheral blood B cells without affecting the concomitant enhancement of CD23, CD40, HLA-DR and surface IgM expression, indicating that its effect is specific for IL-4R up-regulation. When S-oligo 1 was added to B cells costimulated with IL-4 and anti-CD40 MoAb, it induced a dose-dependent inhibition of IgE production. This inhibition was accompanied by a decrease in the expression of mature C epsilon transcripts, whereas the accumulation of germ-line C epsilon transcripts was not affected by S-oligo 1. These data suggest that the signal transduction mediated by the up-regulated IL-4R on B cells may be intimately associated with the induction of isotype switching to IgE that leads to mature C epsilon transcription and IgE production.

[Inhibitory effect of histamine-added mouse gamma-globulin on eosinophil accumulation induced by allergen in BALB/c mice]

Histamine-added human gamma-globulin (HG) has been clinically used as an anti-allergic drug for asthma, allergic rhinitis and atopic dermatitis. Retrospective analysis of clinical data have indicated that s.c. administration with HG not only improves clinical symptoms but also suppresses the number of eosinophils of nasal secretion or peripheral blood in allergic patients. Thus, the possibility was explored that HG may actively suppress eosinophil accumulation in allergic inflammation. The eosinophil accumulation in peritoneal cavity was induced by i.p. injection with ragweed pollen extract in BALB/c mice which had been repeatedly sensitized with the allergen for three weeks. Histamine-added mouse gamma-globulin (Mouse HG) at 150 mg/kg/day markedly inhibited the allergen-induced eosinophil accumulation when administered s.c. two times a week for three weeks. The inhibitory effect was almost the same as that of cyclosporin A at 100 mg/kg/day. Interestingly, equivalent dose of histamine or mouse gamma-globulin alone had no inhibitory effect in the same system. These results suggest that HG suppresses chronic allergic inflammation through the inhibition of eosinophil accumulation.

Biological activities and antitumor effects of synthetic lipid A analog linked N-acylated serine

The mitogenicity, lethal toxicity, production of nitric oxide (NO), induction of tumor necrosis factor (TNF) and antitumor activity against Meth A fibrosarcoma by chemically synthesized N-acylated serine-linked non-phosphorylated (A-606 and A607) and phosphorylated (A-608) acylglucosamine-derived lipid A analog were determined. Compounds A-606, A-608 and A-103 [with (R)-3-tetradecanoyloxytetradecanoyl at the C-2 and C-3 positions] induced significant incorporation of [3H]thymidine into splenocytes of C3H/He mice at concentrations ranging from 3.13 to 50 microM. However, A-607 [with (R)-3-tetradecanoyloxytetradecanoyl and with tetradecanoyl at the C-2 and C-3 positions] showed most significant incorporation of [3H]thymidine. The compounds A-606, A-608 and A-103 did not exhibit the lethality at doses of 30 and 300 nmol/kg in C57BL/6 mice loaded with D-galactosamine, whereas A-607 caused the death of two out of six mice at a dose of 300 nmol/kg. These compounds, except A-607, exhibited little NO production by macrophages, but did cause NO production in the presence of interferon-gamma (IFN-gamma). Peritoneal macrophages, stimulated with A-606-A-608, caused production of TNF which induce L929 cell lysis in vitro, and A-608 showed high production of TNF. NO-inducible activity and induction of TNF by compound A-103 seemed to be lower than that of serine-linked derivatives. A-607, A-608 and A-103 showed antitumor activity against Meth A fibrosarcoma in BALB/c mice, and furthermore, the enhancement of antitumor activity by a combination of A-608 with muramyl dipeptide (MDP) was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of spirochetes isolated from wild rodents in Japan as Borrelia japonica

Spirochetes isolated from three species of wild mice, Apodemus speciosus, Apodemus argenteus, and Eothenomys smithi, which were caught on Honshu, Japan, were characterized on the bases of protein profiles, reactivities with monoclonal antibodies (MAbs), and DNA homology values. All the isolates reacted with MAb O1441b, which is specific for Borrelia japonica, but not with MAb P62, which is specific for Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii. The DNA relatedness of four representatives isolates to strain HO14, a type strain of B. japonica, was 83 to 88%. From these findings, the spirochetes were identified as B. japonica.

A new method for automatic identification of coronary arteries in standard biplane angiograms

A new computerized method for analyzing biplane coronary arteriograms was proposed. The method extracted the vessels in an image, detected branching points, and identified vessel segments according to their anatomical names. The method was applied to a pair of orthogonal projection images acquired in the right anterior oblique and left anterior oblique views. It recognized the corresponding vessel segments in the images and labeled them correctly by their anatomical names. For diameter measurement, a combined first and second derivative filter process was applied to the images along the skeleton lines of the extracted vessel segments. We also designed a method of representation in which vessel diameters measured in the two projection images could be displayed in a single image.

Recombinant soluble form of the human high-affinity immunoglobulin E (IgE) receptor inhibits IgE production through its specific binding to IgE-bearing B cells

A recombinant soluble form of the alpha subunit of the human high-affinity receptor for IgE (rsFc epsilon RI alpha), one of the potent IgE-binding molecules, was tested for its ability to regulate IL-4-induced IgE synthesis by human lymphocytes. Addition of rsFc epsilon RI alpha to cultures induced a dose-dependent inhibition of the T cell-dependent and independent synthesis of IgE. The suppression of IgE synthesis was observed at the protein and the mRNA levels, and it was IgE class specific. By flow cytometry, specific binding of rsFc epsilon RI alpha was detected on surface IgE-bearing B cells as well as on U266 cells, and it was completely blocked by preincubation with IgE. rsFc epsilon RI alpha bound to the cell surface IgE could be effectively dissociated not only by a large excess of IgE, but also by an anti-rsFc epsilon RI alpha mAb that competes with IgE for the binding to rsFc epsilon RI alpha. This mAb abolished the rsFc epsilon RI alpha-mediated suppression of IgE synthesis. These data suggest that rsFc epsilon RI alpha may have a function in selectively suppressing IgE synthesis through its interaction with the membrane-bound form of IgE.

Relationship between infectivity and OspC expression in Lyme disease Borrelia

Borrelia burgdorferi sensu stricto strain 297 and B. garinii strains HP1 and 12-92 were serially subcultured for 36-50 passages in vitro for 1 year. All low-passage strains showed abundant expression of outer surface protein C (OspC) in the 22-23-kDa range, but the high-passage strains lost or showed reduced expression of OspC in comparison with the low-passage strains. The low-passage strains efficiently infected outbred ddY mice when inoculated into the hind footpad or peritoneal cavity. In contrast, the incidence of infection with the high-passage strains was low. Isolates from the bladders of mice inoculated with the high-passage strains expressed large amounts of OspC in comparison with those originally inoculated. These results indicate that OspC expression is related to the infectivity of Lyme disease borreliae.