Clinical characteristics of lupus enteritis in Japanese patients: the large intestine-dominant type has features of intestinal pseudo-obstruction

This study was performed to investigate the clinical characteristics of lupus enteritis in Japanese patients with systemic lupus erythematosus (SLE). A total of 481 patients with SLE admitted to our hospital between 2001 and 2015 were retrospectively reviewed. Diagnosis of lupus enteritis was based on the following three criteria: (1) abdominal symptoms, (2) diffuse long-segment bowel thickening and (3) a requirement for glucocorticoid therapy. Lupus enteritis was identified in 17 patients (3.5%) and there were two distinct types: small intestine-dominant and large intestine-dominant. Significant differences between the two types were noted with respect to the age, frequency of biopsy-proven lupus nephritis, frequency of rectal involvement, maximum bowel wall thickness, and requirement for steroid pulse therapy. Among patients with large intestine-dominant lupus enteritis, 60% had extra-intestinal symptoms (hydroureter, bladder wall thickening, and bile duct dilatation) that are known complications of intestinal pseudo-obstruction. Two patients with large intestine-dominant lupus enteritis developed intestinal pseudo-obstruction either before or after diagnosis of lupus enteritis. Five patients (29%) developed recurrence during a median observation period of 7.2 years (1.4-14.4 years). In conclusion, large intestine-dominant lupus enteritis resembles intestinal pseudo-obstruction and these two diseases may have a common pathogenesis.

Toll-like receptor 2 ligand and interferon-γ suppress anti-tumor T cell responses by enhancing the immunosuppressive activity of monocytic myeloid-derived suppressor cells

CD11b⁺Gr1⁺ myeloid-derived suppressor cells (MDSCs) suppress activation/proliferation of cytotoxic T cells, thereby hindering cancer immunotherapy. MDSCs are increased after adjuvant therapy with toll-like receptor (TLR) 2 ligands, such as Pam2CSK4, in tumor-bearing mice. However, it remains unknown if the activation of TLR2 in MDSCs affects their function and the therapeutic efficacy of TLR2 ligand. Here, we show that TLR2 signaling in CD11b⁺Ly6G⁻Ly6C^high monocytic MDSCs (M-MDSCs), but not CD11b⁺Ly6G⁺Ly6C^low granulocytic MDSCs (G-MDSCs), enhances their immunosuppressive activity, thereby limiting anti-tumor T cell responses induced by TLR2-activated dendritic cells (DCs). iNOS induction was critical for Pam2CSK4-enhanced T cell suppression by M-MDSCs. iNOS was expressed in M-MDSC-derived macrophages, but not undifferentiated M-MDSCs, in cocultures with CD8⁺ T cells, CD11c⁺ DCs, antigen peptide and Pam2CSK4. Pam2CSK4 increased the differentiation frequency of M-MDSCs to macrophages, and iNOS expression required interferon-γ (IFN-γ) production by CD8⁺ T cells that had been transiently stimulated by M-MDSC-derived macrophages in an antigen/TLR2-dependent manner. Although Pam2CSK4 triggered DC maturation and tumor regression via induction of tumor antigen-specific cytotoxic T lymphocyte (CTL) responses in tumor-bearing mice, Pam2CSK4 plus antigen increased the frequency of iNOS⁺ macrophages in the tumor. Treatment with iNOS inhibitor enhanced the therapeutic efficacy of Pam2CSK4. Hence, the results suggest that TLR2 ligand and T cell-derived IFN-γ enhance M-MDSC-mediated immunosuppression, which may negatively regulate anti-tumor CTL response.

Ultrasonography of Thymoma with Pathologic Correlation

Preoperative ultrasonograms of 11 surgically proved thymomas and ex vivo ultrasonograms of 3 resected specimens were compared with pathologic findings of resected specimens. Among 11 thymomas 7 appeared solid, 3 were solid with several cystic regions, and the remaining one was unilocular cystic in appearance. Cystic regions on ultrasonograms corresponded to cystic changes on pathologic specimens. Six malignant thymomas showed a typical lacy appearance on ultrasonograms, which corresponded to the lobulated configuration separated by fibrous septa shown on the pathologic specimens.

Molecular Evolution and Functional Characterization of a Bifunctional Decarboxylase Involved in Lycopodium Alkaloid Biosynthesis

Lycopodium alkaloids (LAs) are derived from lysine (Lys) and are found mainly in Huperziaceae and Lycopodiaceae. LAs are potentially useful against Alzheimer's disease, schizophrenia, and myasthenia gravis. Here, we cloned the bifunctional lysine/ornithine decarboxylase (L/ODC), the first gene involved in LA biosynthesis, from the LA-producing plants Lycopodium clavatum and Huperzia serrata We describe the in vitro and in vivo functional characterization of the L. clavatum L/ODC (LcL/ODC). The recombinant LcL/ODC preferentially catalyzed the decarboxylation of l-Lys over l-ornithine (l-Orn) by about 5 times. Transient expression of LcL/ODC fused with the amino or carboxyl terminus of green fluorescent protein, in onion (Allium cepa) epidermal cells and Nicotiana benthamiana leaves, showed LcL/ODC localization in the cytosol. Transgenic tobacco (Nicotiana tabacum) hairy roots and Arabidopsis (Arabidopsis thaliana) plants expressing LcL/ODC enhanced the production of a Lys-derived alkaloid, anabasine, and cadaverine, respectively, thus, confirming the function of LcL/ODC in plants. In addition, we present an example of the convergent evolution of plant Lys decarboxylase that resulted in the production of Lys-derived alkaloids in Leguminosae (legumes) and Lycopodiaceae (clubmosses). This convergent evolution event probably occurred via the promiscuous functions of the ancestral Orn decarboxylase, which is an enzyme involved in the primary metabolism of polyamine. The positive selection sites were detected by statistical analyses using phylogenetic trees and were confirmed by site-directed mutagenesis, suggesting the importance of those sites in granting the promiscuous function to Lys decarboxylase while retaining the ancestral Orn decarboxylase function. This study contributes to a better understanding of LA biosynthesis and the molecular evolution of plant Lys decarboxylase.

Myeloid-derived suppressor cells confer tumor-suppressive functions on natural killer cells via polyinosinic:polycytidylic acid treatment in mouse tumor models

Polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA, acts on myeloid cells and induces potent antitumor immune responses including natural killer (NK) cell activation. Myeloid-derived suppressor cells (MDSCs) systemically exist in tumor-bearing hosts and have strong immunosuppressive activity against antitumor effector cells, thereby dampening the efficacy of cancer immunotherapy. Here we tested what happened in MDSCs in poly I:C-treated mice. NK-sensitive syngenic tumor (B16)-bearing C57BL/6 mice were employed for this study. Intraperitoneal poly I:C treatment induced MDSC activation, driving CD69 expression and interferon (IFN)-γ production in NK cells. IFN-γ directly inhibited proliferation of B16 cells. This NK cell priming led to growth retardation of B16 tumors, although no direct tumoricidal activity was induced in NK cells. Mechanistic analysis using KO mice and function-blocking monclonal antibody revealed that MDSCs produced IFN-α via the mitochondrial antiviral signaling protein (MAVS) pathway after in vivo administration of poly I:C, and activated NK cells through the IFNAR pathway. MDSC-mediated NK cell priming was reconstituted by IFN-α in a coculture system. Either the MAVS or IFNAR signaling pathway was required for activation of MDSCs that led to growth retardation of B16 tumor in vivo. The results infer that MDSC is a target of poly I:C to prime NK cells, which exert antitumor activity to NK-sensitive tumor cells.

Dendritic cells from oral cavity induce Foxp3(+) regulatory T cells upon antigen stimulation

Evidence is accumulating that dendritic cells (DCs) from the intestines have the capacity to induce Foxp3(+)CD4(+) regulatory T cells (T-regs) and regulate immunity versus tolerance in the intestines. However, the contribution of DCs to controlling immunity versus tolerance in the oral cavity has not been addressed. Here, we report that DCs from the oral cavity induce Foxp3(+) T-regs as well as DCs from intestine. We found that oral-cavity-draining cervical lymph nodes contained higher frequencies of Foxp3(+) T-regs and ROR-γt(+) CD4(+)T cells than other lymph nodes. The high frequency of Foxp3(+) T-regs in the oral-cavity-draining cervical lymph nodes was not dependent on the Toll like receptor (TLR) adaptor molecules, Myd88 and TICAM-1 (TRIF). In contrast, the high frequency of ROR-γt(+) CD4(+)T cells relies on Myd88 and TICAM-1. In vitro data showed that CD11c(+) DCs from oral-cavity-draining cervical lymph nodes have the capacity to induce Foxp3(+) T-regs in the presence of antigen. These data suggest that, as well as in the intestinal environment, antigen-presenting DCs may play a vital role in maintaining tolerance by inducing Foxp3(+) T-regs in the oral cavity.

TLR2-dependent induction of IL-10 and Foxp3+ CD25+ CD4+ regulatory T cells prevents effective anti-tumor immunity induced by Pam2 lipopeptides in vivo

16 S-[2,3-bis(palmitoyl)propyl]cysteine (Pam2) lipopeptides act as toll-like receptor (TLR)2/6 ligands and activate natural killer (NK) cells and dendritic cells (DCs) to produce inflammatory cytokines and cytotoxic NK activity in vitro. However, in this study, we found that systemic injection of Pam2 lipopeptides was not effective for the suppression of NK-sensitive B16 melanomas in vivo. When we investigated the immune suppressive mechanisms, systemic injection of Pam2 lipopeptides induced IL-10 in a TLR2-dependent manner. The Pam2 lipopeptides increased the frequencies of Foxp3⁺CD4⁺ regulatory T (T reg) cells in a TLR2- and IL-10- dependent manner. The T reg cells from Pam2-lipopeptide injected mice maintained suppressor activity. Pam2 lipopeptides, plus the depletion of T reg with an anti-CD25 monoclonal antibody, improved tumor growth compared with Pam2 lipopeptides alone. In conclusion, our data suggested that systemic treatment of Pam2 lipopeptides promoted IL-10 production and T reg function, which suppressed the effective induction of anti-tumor immunity in vivo. It is necessary to develop an adjuvant that does not promote IL-10 and T reg function in vivo for the future establishment of an anti-cancer vaccine.

Abundance of Virus-Sized Non-DNase-Digestible DNA (Coated DNA) in Eutrophic Seawater

Total DNA concentration in 0.2-mum-pore-size Nuclepore filter filtrates (<0.2-mum fraction) of Tokyo Bay water was estimated to be 9 to 19 ng/ml by an immunochemical quantification method. Almost 90% of the DNA in the <0.2-mum fraction was found in the size fractions larger than 3.0 x 10 Da and 0.03 mum, and most was not susceptible to DNase digestion, that is, consisted of non-DNase-digestible DNA (coated DNA). A significant amount of DNA was obtained from the <0.2-mum fraction of the seawater by three different methods: polyethylene glycol precipitation, direct ethanol precipitation, and ultrafilter concentration. Gel electrophoresis analysis of the isolated DNAs showed that they consisted mainly of coated DNAs with a similar molecular sizes (20 to 30 kb [1.3 x 10 to 2.0 x 10 Da). The abundance of the ultramicron virus-sized coated DNA in natural seawater suggests that these DNA-rich particles can be attributed to marine DNA virus assemblages and that they may be a significant phosphorus reservoir in the environment.

Activities and distribution of methanogenic and methane-oxidizing microbes in marine sediments from the Cascadia Margin

We investigated methane production and oxidation and the depth distribution and phylogenetic affiliation of a functional gene for methanogenesis, methyl coenzyme M reductase subunit A (mcrA), at two sites of the Integrated Ocean Drilling Program Expedition 311. These sites, U1327 and U1329, are respectively inside and outside the area of gas hydrate distribution on the Cascadia Margin. Radiotracer experiments using (14)C-labelled substrates indicated high potential methane production rates in hydrate-bearing sediments [128-223 m below seafloor (mbsf)] at U1327 and in sediments between 70 and 140 mbsf at U1329. Tracer-free experiments indicated high cumulative methane production in sediments within and below the gas hydrate layer at U1327 and in sediments below 70 mbsf at U1329. Stable tracer experiments using (13)C-labelled methane showed high potential methane oxidation rates in near-surface sediments and in sediments deeper than 100 mbsf at both sites. Results of polymerase chain reaction amplification of mcrA in DNA were mostly consistent with methane production: relatively strong mcrA amplification was detected in the gas hydrate-bearing sediments at U1327, whereas at U1329, it was mainly detected in sediments from around the bottom-simulating reflector (126 mbsf). Phylogenetic analysis of mcrA separated it into four phylotype clusters: two clusters of methanogens, Methanosarcinales and Methanobacteriales, and two clusters of anaerobic methanotrophic archaea, ANME-I and ANME-II groups, supporting the activity measurement results. These results reveal that in situ methanogenesis in deep sediments probably contributes to gas hydrate formation and are inconsistent with the geochemical model that microbial methane currently being generated in shallow sediments migrates downward and contributes to the hydrate formation. At Site U1327, gas hydrates occurred in turbidite sediments, which were absent at Site U1329, suggesting that a geological setting suitable for a gas hydrate reservoir is more important for the accumulation of gas hydrate than microbiological properties.

16S rRNA gene sequence-based analysis of clostridia related to conversion of germfree mice to the normal state

AIMS

To determine phylogenetic groups of clostridia inhabiting the mouse intestine that are essential for normalization of germfree (GF) mice.

METHODS AND RESULTS

Using both the culture method and cloning, clostridia inhabiting the mouse intestine were isolated, and phylogenetic analysis based on 16S rRNA gene sequences was carried out. As a result, the isolates were found to have novel sequences, and no isolate was determined to be identical to previously known identified clostridia. Although the taxonomy of mouse intestinal clostridia was complex, many of them belonged to Clostridium clusters XIVa and IV in conventional (CV) and limited flora mice and ex-germfree mice administered chloroform-treated CV mouse faeces. The clostridia that belonged to cluster XIVa were most often present and showed the highest diversity.

CONCLUSIONS

Clostridia belonging clusters XIVa and IV are dominant in the mouse intestine as in other gut ecosystems. The novel groups in these clusters are essential for normalization of GF mice.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study can be applied in the strict control of mouse intestinal microbiota and will provide important information for normalization of GF mice and also for research on microbiology of the mouse intestine.

Ray tracing of an aspherical lens with antireflective subwavelength structured surfaces

A method of ray tracing for an aspherical lens with subwavelength periodic structured surfaces has been developed. The ray tracing in the antireflective subwavelength structure is based on the group velocity of the Bloch wave. Transmittance and phase delay for the surface structure are determined with rigorous coupled wave analysis. Calculated wavefront aberration was smaller than 20 mlambda for an aspherical lens with numerical aperture of 0.6. For a lens with a higher numerical aperture, the wavefront aberrations increase drastically.

Age-related three-dimensional morphological changes in rat motoneurons innervating diaphragm and longissimus muscles

We investigated age-related morphological changes of rat motoneurons innervating diaphragm muscle (DI-MN) and lumber longissimus muscle (LL-MN) in which quite different activation patterns exist. In young (2-4 months) and old (24-26 months) rats, the motoneurons innervating both muscles were labelled retrogradely by intramuscular injection of cholera toxin B subunit. After a 4-day survival, horizontal slices of the spinal cord were processed with immunohistochemical staining (first antibody to cholera toxin B subunit and second antibody with Cy3) and observed with a confocal microscope. Three-dimensional reconstruction of labelled motoneurons was performed to examine soma and dendrite morphology. As compared to the soma volume in young rats, significantly smaller values were found in old rats in both motoneurons and the degrees of decline were 16.1% in DI-MN and 20.3% in LL-MN. Significant decreases in the thickness of primary dendrites were also found in both motoneurons, and the degrees of decline were 17.5% in DI-MN and 22.3% in LL-MN. Smaller changes were found in DI-MN than in LL-MN, indicating the possibility that increased activation by central drives can attenuate age-related morphological changes of the motor system in the spinal cord.

Spatial and temporal distribution of the vibrionaceae in coastal waters of Hawaii, Australia, and France

Relatively little is known about large-scale spatial and temporal fluctuations in bacterioplankton, especially within the bacterial families. In general, however, a number of abiotic factors (namely, nutrients and temperature) appear to influence distribution. Community dynamics within the Vibrionaceae are of particular interest to biologists because this family contains a number of important pathogenic, commensal, and mutualist species. Of special interest to this study is the mutualism between sepiolid squids and Vibrio fischeri and Vibrio logei, where host squids seed surrounding waters daily with their bacterial partners. This study seeks to examine the spatial and temporal distribution of the Vibrionaceae with respect to V. fischeri and V. logei in Hawaii, southeastern Australia, and southern France sampling sites. In particular, we examine how the presence of sepiolid squid hosts influences community population structure within the Vibrionaceae. We found that abiotic (temperature) and biotic (host distribution) factors both influence population dynamics. In Hawaii, three sites within squid host habitat contained communities of Vibrionaceae with higher proportions of V. fischeri. In Australia, V. fischeri numbers at host collection sites were greater than other populations; however, there were no spatial or temporal patterns seen at other sample sites. In France, host presence did not appear to influence Vibrio communities, although sampled populations were significantly greater in the winter than summer sampling periods. Results of this study demonstrate the importance of understanding how both abiotic and biotic factors interact to influence bacterial community structure within the Vibrionaceae.

Determinants for Prediction of Malignant Potential by Metalloproteinase:E-Cadherin Ratio in Prostate Core Needle Biopsy

According to a good correlation between in situ hybridization-based metalloproteinase-2/9:E-cadherin ratio (MER) and the pathological stage of prostate cancer, we set the cutoff line of MER at 6.0 (MER>6) to distinguish between organ-confined (pT2) and advanced diseases (pT3a-b/N1). In this study, we looked at the factors affecting MER and leading to a misprediction of the pathological stage. We examined MER in 39 paired specimens of prostate core needle biopsy and prostatectomy from the same patient and compared these MERs. In 34 (87%) of 39 cases, the MER of biopsy was correlated with the final pathological stage (pT2 vs. pT3a-b/N1). MER ranges in pT3a-b/N1 cancer were significantly wider than those in pT2 cancer (p < 0.01). The number of MER>6 fields in Gleason score 8-9 cancer was larger than that in Gleason score 7 cancer (p < 0.0001). In 5 cases where there was a failure to distinguish pT2 from pT3a-b/N1, the misdiagnosis was significantly associated with a small number of biopsies (4 or 6 specimens; p = 0.0469), a small amount of tumor tissue in biopsy specimens (less than 5 mm; p = 0.0492), and a wide MER range (more than 5.0; high intratumoral heterogeneity; p = 0.0202). Considering these factors increases the usefulness of preoperative prediction of the final pathological stage by MER in prostate cancer.

Estimation method for the light extraction efficiency of light-emitting elements with a rigorous grating diffraction theory

The light extraction efficiency of a light-emitting element with microstructured surface is analyzed with a rigorous grating diffraction theory. The grating theory reveals an improvement of extraction efficiency due to diffraction of light by the surface microstructure. The simulation results show that the improvement of extraction efficiency is due mainly to the reflected diffraction rather than to the transmitted diffraction. A part of total-internal-reflection light is diffracted into directions at less than the critical angle. Extraction efficiency is improved by multiple reflection and diffraction of light in a high-refractive-index layer. We propose a simple design method for an efficient surface microstructure from the viewpoint of reflected diffraction.

pH-sensing nano-crystals of carbonate apatite: effects on intracellular delivery and release of DNA for efficient expression into mammalian cells

Two unique and fascinating properties of carbonate apatite which are well-known in hard tissue engineering, have been unveiled, for the first time, for the development of the simplest, but most efficient non-viral gene delivery device - ability of preventing the growth of crystals needed for high frequency DNA transfer across a plasma membrane and a fast dissolution rate for effective release of DNA during endosomal acidification, leading to a remarkably high transgene expression (5 to 100-fold) in mammalian cells compared to the widely used transfecting agents. Moreover, by modulating the crystal dissolution rate of carbonate apatite through incorporation of fluoride or strontium into it, transfection activity could be dramatically controlled, thus shedding light on a new barrier in the non-viral route, which was overlooked so far. Thus we have developed an innovative technology with significant insights, that would come as a promising tool for both basic research laboratories and clinical settings.

Brain-derived neurotrophic factor increases inhibitory synapses, revealed in solitary neurons cultured from rat visual cortex

To elucidate chronic actions of brain-derived neurotrophic factor (BDNF) on GABAergic synapses, we examined effects of a long-term application of BDNF for 10-15 days on autapses (synapses) of solitary GABAergic neurons cultured from rat visual cortex. Solitary neuron preparations were used to exclude a possible contamination of BDNF actions on excitatory neurons in dissociated neuron culture or slice preparations. Neurons were confirmed to be GABAergic pharmacologically with bicuculline, a selective antagonist for GABAA receptors and immunocytochemically with antibody against glutamic acid decarboxylase 65, a GABA synthesizing enzyme. To evaluate GABAergic synaptic function, evoked and/or miniature inhibitory postsynaptic currents (IPSCs) were recorded in the whole-cell voltage-clamp mode. The treatment with BDNF at a concentration of 100 ng/ml enhanced the amplitude of evoked IPSCs and the frequency of miniature IPSCs. In contrast, BDNF did not have a detectable effect on the amplitude of miniature IPSCs and the paired pulse ratio of IPSCs evoked by two, successive activations. To evaluate morphological changes, neurons were immunocytochemically stained with antibodies against microtubule-associated protein 2, to visualize somatodendritic region and synapsin I, to visualize presynaptic sites. The quantitative analysis indicated that BDNF increased the area of soma, the numbers of primary dendrites and dendritic branching points, the total length of dendrites and the number of synaptic sites. Such an action of BDNF was seen in both subgroups of GABAergic neurons, parvalbumin-positive and -negative neurons. To visualize functionally active presynaptic sites, neurons were stained with a styryl dye, FM1-43. BDNF increased the number of stained sites that was correlated with the frequency of miniature IPSCs. These results suggest that the chronic treatment with BDNF promotes dendritic and synaptic development of GABAergic neurons in visual cortex.

Dynamics of microbial populations and strong selection for Cycloclasticus pugetii following the Nakhodka oil spill

Microbial population changes were monitored immediately after the Nakhodka oil spill accident in January 1997 at the heavily oil-contaminated Mikuni coast along the Sea of Japan. The total cell number was almost stable for one year at 2-5 x 10(5) cells mL(-1), while the relative occurrence of culturable heterotrophs and degraders of oil components such as C-heavy oil, kerosene, and n-tetradecane varied, showing a maximum (>50% of the total) immediately following the accident. Gene amplification and phylogenetic analysis of a dilution culture using C-heavy oil as the sole carbon and energy source revealed that one of the predominant oil degraders at the oil-contaminated coast in 2 weeks after the accident closely resembled the aromatic hydrocarbon decomposer Cycloclasticus pugetii. Microbial community composition in oil-contaminated seawater was estimated at the molecular level using newly developed oligonucleotide probes, probe wash-off curve estimation, and quantitative fluorescence dot-blot hybridization techniques. At two different oil-polluted sites, harbor and intertidal regions, the C. pugetii group was estimated to make up 23-25% of the total Bacteria population, followed by the aliphatic hydrocarbon decomposer Alcanivorax borkumensis, which formed 4-7% of the Bacteria. In incubation experiments using floated oil slick and indigenous microbes collected at the harbor, oil degradation activities were enhanced by the addition of both organic and inorganic nutrients. Significant decreases were found in aromatic and aliphatic hydrocarbon fractions: 54-60% and 22-24% in 2 weeks to 68-77% and 23-32% in 2 months, respectively.

Triplex formation using ODN conjugates with polycation comb-type copolymer

Polycation comb-type copolymer that is composed of polylysine backbone and dextran side chains (PLL-g-Dex) has previously been shown to stabilize duplex and triplex DNAs quite effectively. In this study, we have conjugated PLL-g-Dex with oligonucleotides (ODN) aiming to increase the triplex stabilizing efficiency of the copolymer. Here we have demonstrated that the copolymer-TFO conjugates selectively stabilize triplex DNA. Also its potential to form triplex DNA was found to be greater than PLL-g-Dex/ODN mixture.

Acceleration of DNA strand exchange by polycation comb-type copolymer

The accelerating effect of cationic substances on DNA strand exchange reaction between 20 bp DNA duplex and its complementary single strand was studied. A comb-type polycationic copolymer which is composed of poly (L-lysine) backbone and dextran graft chain (PLL-g-Dex) and known to stabilize triplex DNA expedites the strand exchange reaction under physiological relevant conditions. Electrostatically small excess of the copolymer increased DNA strand exchange rate by 300-fold while large excess of spermine or cethyltrimethylammonium bromide, cationic detergent known to promote markedly hybridization of complementary DNA strands, showed slight effect. It should be noted that the copolymer promotes the strand exchange reaction while it stabilizes double stranded DNA.

Synergistic stabilization of triplex by combination of comb-type cationic copolymer and oligo-N3'-->P5' phosphoramidates

In the present study, we describe rapid formation of stable pyrimidine motif triplex at physiological pH. The triplex formation was achieved by the synergistic effect of poly(L-lysine)-graft-dextran (PLL-g-Dex) copolymer and N3'-->P5' phosphoramidate (PN) backbone modification of triplex-forming oligonucleotide (TFO). Either the PLL-g-Dex copolymer or the PN modification alone increased the binding constant by nearly two orders of magnitude for the triplex formation at neutral pH. The combination of both stabilizing factors that was the triplex formation with the PN TFO in the presence of the copolymer increased the binding constant by nearly four orders of magnitude. The kinetic study indicated that the copolymer increased the association rate constant, whereas the PN modification decreased the dissociation rate constant. No negative interference between these stabilizing effects was observed. The kinetically orchestrated effects in which the copolymer and the PN TFO contribute to distinct ingredients in triplex equilibrium achieved the rapid formation of the stable triplex.

Protein/oligonucleotide conjugates as a cell specific PNA carrier

We have focused on proteineus ligand conjugate with oligonucleotides (ODNs) as a cell-specific delivery vector for peptide nucleic acids (PNAs). Asialofetuin (AF), a hepatocyte-specific proteineus ligand, was conjugated with ODNs that served as binding sites for PNAs. Succinimidyl-transe-4(N-maleimidylmethyl)-cyclohexane-1-carboxylate (SMCC) modified AF was coupled with 5'-thiolated oligodeoxynucleotide (HS-ODN). The resulting conjugate held PNAs with sequence-specific manner. The PNA/DNA conjugate complex has resistance against nucleases in serum. The efficient release of PNA from the complex was observed when the complex was made in contact with a target nucleotide. PNA uptake to hepatocytes was greatly enhanced when hepatocytes was incubated with PNA/conjugate complex. Free AF thoroughly inhibited PNA uptake with the conjugate, evidencing asialoglycoprotein receptor (ASGP-R) mediated endocytosis to be a major-route for the cellular uptake.

Polycation graft copolymers accelerating DNA strand exchange: involvement of ionic interaction

In the previous study (Chem. Eur. J., 7, 176 (2001)) we demonstrated that the comb-type polycationic copolymer (PLL-g-Dex) which is composed of poly (L-lysine) backbone and dextran graft chains expedited the DNA strand exchange reaction. In this study, fluorescence resonance energy transfer (FRET) was employed to explore the copolymer-mediated DNA strand exchange with higher time-resolution. To initiate strand exchange reaction the duplex prepared from 3'-fluorescein isothiocyanate (FITC)--and 5'-carboxytetramethylrhodamine(TAMRA)-labeled complementary DNAs was added to its non-labeled complementary single strand. DNA strand exchange was monitored by observing the recovery of the FITC quenching. More than 20,000 times increase in strand exchange rate at 37 degrees C by the copolymer was estimated. To investigate the accelerating mechanisms of the copolymer, the same reactions but at various ionic strenghts were studied. With increasing ionic strengths the strand exchange rate in the absence of the copolymer increased, suggesting that ionic repulsion among DNAs is unfavorable for the strand exchange to occur. Hence, alleviation of the electrostatic repulsion through interpolyelectrolyte complex formation is probably a role of the copolymer for accelerating the strand exchange reaction.

Clear cell myoepithelial carcinoma of the breast: a case report

Primary clear cell myoepithelial carcinoma (CCMC) is extremely rare. During the past twenty years, only one CCMC case has been reported. Here, a case of CCMC is reported. A 30-year-old woman became aware of an abnormal mass on the left breast, and quadrantectomy was performed. Microscopically, it consisted of tumor cells that had clear cytoplasm and showed an invasive growth pattern. Immunohistochemically, the tumor was positive for alpha-smooth muscle actin, S-100, partly positive for vimentin and epithelial membranous antigen. From these findings, the tumor was diagnosed as CCMC. Most of the clear cell myoepithelial tumors are probably misclassified in other examples. It is expected that the numbers of CCMC may be increased by routinely performing special stains and immunohistochemical stains, even without ultrastructual study.

Cancer history and loss of MSH2 and MLH1 protein expression in patients with endometrial hyperplasia

In order to evaluate the hereditary background of endometrial hyperplasia patients in relation to protein expression of DNA mismatch repair genes, we evaluated 69 patients with endometrial hyperplasia and 18 patients with normal endometrium having both a personal and family history of cancer (two hereditary nonpolypoid colorectal cancer (HNPCC) patients). We obtained personal and family histories of cancer for all patients. MSH2 and MLH1 protein expression was investigated by immunohistochemical methods. In the endometrial hyperplasia patients, 11 had personal histories and 40 had family histories of cancer. Among the 11 endometrial hyperplasia patients with a personal history of cancer, most cancers were breast or colorectal cancers (82%). In the 40 patients with a family history of cancer, colorectal cancer (33%) was the most frequent. The incidence of loss of expression of MSH2 and/or MLH1 protein in endometrial hyperplasia patients with personal (64%) or family (40%) histories was significantly higher than that in patients without such history (no personal: 21% and no family: 10%; P = 0.0035 and 0.0065). No protein loss was detected in any of the cases with normal endometrium having either a personal or family history of cancer. Our results suggest that a portion of endometrial hyperplasia cases having a personal or family history of cancer may belong to HNPCC, and that in these cases, abnormality of the mismatch repair system may be an early event in endometrial carcinogenesis.

Long-term follow-up of hepatitis C virus infection: HLA class II loci influences the natural history of the disease

Hepatitis C virus (HCV) causes various grades of chronic liver disease, ranging from an asymptomatic state to cirrhosis. To assess genetic factors of disease severity, we selected two HCV patient groups according to the following stringent criteria: (i) asymptomatic carrier state (ASC) defined by HCV infection for more than 20 years, normal alanine aminotransferase levels for the past 5 years as well as normal liver histology and/or shape and (ii) liver cirrhosis (LC) as diagnosed by clinical symptoms, liver biopsy and/or ultrasonography. A total of 103 chronically infected Japanese HCV patients (43 ASC and 60 LC) were analyzed. HLA class I and II alleles were established using low resolution DNA typing. HLA-DRB1 and DQB1 genotypes were inferred upon polymerase chain reaction-restriction fragment length polymorphism analysis. Two hundred and one anti-HCV-negative ethnically matched controls were included. The frequencies of DRB1*12 (*1201 and *1202), DQB1*0301 and DRB3*03 alleles were higher in patients with ASC than in those with LC (odds ratio (OR) 11.23, OR 4.25, and OR 3.22, respectively). The frequency of DQB1*0503 were lower in ASC patients compared to LC patients (OR 0.05). No significant differences between groups were observed for age, sex, source of infection, HCV genotype or viral loads. Our findings establish that certain HLA class II alleles strongly influence disease progression following HCV infection.

Inhibition of sequence-specific protein-DNA interaction and restriction endonuclease cleavage via triplex stabilization by poly(L-lysine)-graft-dextran copolymer

Triplex stabilization by poly(L-lysine)-graft-dextran copolymer within a mammalian gene promoter inhibits the DNA binding activity of nuclear proteins from HeLa cells as well as restriction endonuclease cleavage at physiological pH and ionic conditions in vitro. Electrophoretic mobility shift assays using a 30-mer homopurine-homopyrimidine stretch (located between -170 and -141 bp) of rat alpha 1 (I) collagen gene promoter reveal that the copolymer, at its wide range of charge ratio with DNA, stabilizes triplex DNA and enhances triplex-specific inhibition of the protein-DNA interaction. When the triplex-forming region (located between -165 and -146 bp) of the promoter is engineered at the Bam H1 and Pst 1 sites of a plasmid DNA, copolymer-mediated triplex stabilization also remarkably competes endonuclease activity of BamH1. Finally, the triplex-stabilizing efficiency of the copolymer is remarkably higher than that of spermine and benzo[e]pyridoindole. Our results indicate that the copolymer, regardless of the length of the target duplex, stabilizes triplexes for significant inhibition of protein-DNA interaction and endonuclease activity. Since stable triplex formation within a short region out of a long native duplex is a prerequisite to confer the therapeutic potential of antigene strategy, triplex stabilization on a long target duplex and inhibition of nuclear protein-DNA interaction may open the possible in vivo applicability of the copolymer.

Design of polymer materials enhancing nucleotide hybridization for anti-gene technology

Stabilization of nucleotide hybridization is considered important for improving gene therapy using oligonucleotides. We have designed comb-type copolymer consisting of polycation backbone (polylysine) and hydrophilic side chains as a stabilizer for double and triple helical DNAs. The copolymer considerably increased the thermal stability of triple helical structure but did not affect the reversible transition between triple helical and single-stranded DNA. An in vitro electrophoretic mobility shift assay revealed that the copolymer remarkably increased association constants of both Hoogsteen and reverse Hoogsteen-type triple helix formation. Moreover the triple helix-stabilizing efficiency of the copolymer was significantly higher than that of other oligocations like spermine and spermidine. Not only being good DNA triple helix stabilizer, it has also been shown to accelerate DNA strand exchange reactions between double helical DNA and its complementary oligonucleotides. From these, we conclude that this copolymer is capable of either 'stabilizing' or 'activating' DNA hybrids, and may useful for gene targeting employing oligonucleotides.

Overexpression of sigma factor, sigma(B), urges Staphylococcus aureus to thicken the cell wall and to resist beta-lactams

Whole genome sequence analysis revealed that Staphylococcus aureus is provided with only a few sigma factors, including the alternative sigma factor, sigma(B), which is thought to regulate some stress responses. Since the sigB knock-out mutant did not show remarkable phenotypic difference, we constructed the over expressed mutant to examine the role of the sigB. Electron microscopic observation revealed that the mutant showed a variety of cell sizes compared with the parent strain which showed almost homogeneous cell sizes. The mutant delivered a thicker cell wall, about 20% thicker than the parent strain. It became resistant to the lytic activity of lysostaphin and also raised MICs to the cell-wall-affecting antibiotics. The yield of carotenoids and transcripts of pbps were also increased in the mutant. The result suggests that sigB plays some important roles in cell wall synthesis and in resistance to antibiotics that perturb the cell wall synthesis.

Clinical value of lung uptake of iodine-123 metaiodobenzylguanidine (MIBG), a myocardial sympathetic nerve imaging agent, in patients with chronic heart failure

This study investigated the clinical value of I-123 MIBG pulmonary accumulation and washout in patients with chronic heart failure (CHF). Nineteen patients with CHF and 15 normal volunteers (NL) were included. The uptake ratio of heart to mediastinum (H/M), that of lung fields to mediastinum (L/M), and washout rate (WR) of the heart and lung fields were calculated in anterior planar images and compared with results of echocardiography and cardiac catheterization. In the CHF group, the lung uptake in delayed images increased and lung WR was decreased, suggesting pulmonary endothelial lesions. Furthermore, there was a negative correlation between right and left lung WR and pulmonary arterial diastolic pressure (PA(D)) and pulmonary arterial systolic pressure (PA(s)) in the CHF group. Since the WR of MIBG reflected PA, it may be used as an index of severity of cardiac dysfunction.