Search for dinucleon decay into kaons in Super-Kamiokande

A search for the dinucleon decay pp → K+ K+ has been performed using 91.6  kton·yr data from Super-Kamiokande-I. This decay provides a sensitive probe of the R-parity-violating parameter λ112''. A boosted decision tree analysis found no signal candidates in the data. The expected background was 0.28±0.19 atmospheric neutrino induced events and the estimated signal detection efficiency was 12.6%±3.2%. A lower limit of 1.7×10(32)  years has been placed on the partial lifetime of the decay O16 → C14K+ K+ at 90% C.L. A corresponding upper limit of 7.8×10(-9) has been placed on the parameter λ112''.

First indication of terrestrial matter effects on solar neutrino oscillation

We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2 ± 1.1(stat) ± 0.5(syst)]%, which deviates from zero by 2.7 σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4 × 10(-5)  eV(2) ≤ Δm 2(21) ≤ 7 × 10(-5) eV(2) and large mixing values of θ12, at the 68% C.L.

Conjugation of peptide nucleic acid with a pyrrole/imidazole polyamide to specifically recognize and cleave DNA

Cut loose: A pseudocomplementary peptide nucleic acid was tethered to a pyrrole/imidazole hairpin polyamide, and was used to selectively target a specific DNA sequence. Binding even occurs under high salt conditions. Furthermore, the conjugate facilitated sequence-specific scission of long dsDNA. This simple approach promises to resolve the technical difficulties in targeting DNA sequences with PNA.

Effect of nicotine on the proliferation and differentiation of mouse induced pluripotent stem cells

The molecular mechanisms that regulate the proliferation and differentiation of induced pluripotent stem (iPS) cells are of great interest. However, whether stimulation with nicotine enhances the proliferation and differentiation of iPS cells has not been investigated. In the present study, western blot analysis revealed that the α4-nAchR and α7-nAchR are expressed in mouse iPS cells. Mouse iPS cells were treated with nicotine for 24 h under feeder-free conditions. Mouse iPS cells were guided to differentiate into mesodermal progenitor cells on type IV collagen (Col IV)-coated dishes in differentiation medium. Mouse iPS cells were guided to differentiate into neural progenitor cells by embryoid body (EB) formation on ultra-low-attachment dishes. After 4 days of growth, all-trans retinoic acid (ATRA; 1 μM) or nicotine (300 nM) was added to the EB cultures and maintained for additional 4 days and plated onto fibronectincoated plates. A BrdU incorporation assay showed that treatment with 300 nM nicotine significantly increased the DNA synthesis of mouse iPS cells or mouse iPS cell-derived mesodermal progenitor cells. This effect was significantly inhibited by pretreatment with an α4-nAchR antagonist, an α7-nAchR antagonist, or a CaMKII inhibitor. The differentiation potential of mouse iPS cells into mesodermal progenitor cells or neural progenitor cells was not affected by the nicotine treatment. The present study indicates that stimulation of the α4-nAchR and α7-nAchR may lead to a significant increase in the proliferation of mouse iPS cells or mouse iPS cell-derived mesodermal progenitor cells through the CaMKII signaling pathway.

Evidence for the appearance of atmospheric tau neutrinos in super-Kamiokande

Super-Kamiokande atmospheric neutrino data were fit with an unbinned maximum likelihood method to search for the appearance of tau leptons resulting from the interactions of oscillation-generated tau neutrinos in the detector. Relative to the expectation of unity, the tau normalization is found to be 1.42 ± 0.35(stat)(-0.12)(+0.14)(syst) excluding the no-tau-appearance hypothesis, for which the normalization would be zero, at the 3.8σ level. We estimate that 180.1 ± 44.3(stat)(-15.2)(+17.8) (syst) tau leptons were produced in the 22.5 kton fiducial volume of the detector by tau neutrinos during the 2806 day running period. In future analyses, this large sample of selected tau events will allow the study of charged current tau neutrino interaction physics with oscillation produced tau neutrinos.

A chemistry-based method to detect individual telomere length at a single chromosome terminus

The understanding of telomeres is expected to provide major insights into genome stability, cancer, and telomere-related diseases. In recent years, there have been considerable improvements in the technologies available to determine the length of telomeres of human chromosomes; however, the present methods for measuring telomere length are fraught with shortcomings that have limited their use. Here we describe a method for detection of individual telomere lengths (DITL) that uses a chemistry-based approach that accurately measures the telomere lengths from individual chromosomes. The method was successfully used to determine telomere DNA by breaking in the target sequence and producing a "real telomere fragment." The DITL approach involves cleavage of the sequence adjacent to the telomere followed by resolution of the telomere length at the nucleotide level of a single chromosome. Comparison of the DITL method and the traditional terminal restriction fragment (TRF) analysis indicates that the DITL approach appears to be promising for the quantification of telomere repeats in each chromosome and the detection of accurate telomere lengths that can be missed using TRF analysis.

Cesium-ion selective electrodes based on calix[4]arene dibenzocrown ethers

Four calix[4]arene dibenzocrown ether compounds have been prepared and evaluated as Cs(+)-selective ligands in solvent polymeric membrane electrodes. The ionophores include 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-6 1, 25,27-bis(1-alkyloxy)calix[4]arene dibenzocrown-7s 2 and 3, and 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-8 4. For an ion-selective electrode (ISE) based on 1, the linear response concentration range is 1x10(-1) to 1x10(-6) M of Cs(+). Potentiometric selectivities of ISEs based on 1-4 for Cs(+) over other alkali metal cations, alkaline earth metal cations, and NH(4)(+) have been assessed. For 1-ISE, a remarkably high Cs(+)/Na(+) selectivity was observed, the selectivity coefficient (K(Cs,Na)(Pot)) being ca. 10(-5). As the size of crown ether ring is enlarged from crown-6 (1) to crown-7 (2 and 3) to crown-8 (4), the Cs(+) selectivity over other alkali metal cations, such as Na(+) and K(+), is reduced successively. Effects of membrane composition and pH in the aqueous solution upon the electrode properties are also discussed.

Oligonucleotide models of telomeric DNA and RNA form a Hybrid G-quadruplex structure as a potential component of telomeres

Telomeric repeat-containing RNA, a non-coding RNA molecule, has recently been found in mammalian cells. The detailed structural features and functions of the telomeric RNA at human chromosome ends remain unclear, although this RNA molecule may be a key component of the telomere machinery. In this study, using model human telomeric DNA and RNA sequences, we demonstrated that human telomeric RNA and DNA oligonucleotides form a DNA-RNA G-quadruplex. We next employed chemistry-based oligonucleotide probes to mimic the naturally formed telomeric DNA-RNA G-quadruplexes in living cells, suggesting that the process of DNA-RNA G-quadruplex formation with oligonucleotide models of telomeric DNA and RNA could occur in cells. Furthermore, we investigated the possible roles of this DNA-RNA G-quadruplex. The formation of the DNA-RNA G-quadruplex causes a significant increase in the clonogenic capacity of cells and has an effect on inhibition of cellular senescence. Here, we have used a model system to provide evidence about the formation of G-quadruplex structures involving telomeric DNA and RNA sequences that have the potential to provide a protective capping structure for telomere ends.

G-rich sequence-specific recognition and scission of human genome by PNA/DNA hybrid G-quadruplex formation

Hole in one: A single peptide nucleic acid (PNA) effectively targets the G-rich region in double-stranded DNA through formation of a PNA/DNA hybrid G-quadruplex. Only one target site in the whole human genome was selectively cleaved by the hybrid G-quadruplex. Such site-selective scission of DNA is central to gene manipulation for molecular biology, biotechnology, and therapy.

Search for differences in oscillation parameters for atmospheric neutrinos and antineutrinos at Super-Kamiokande

We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande-I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best-fit antineutrino mixing is found to be at (Δm2,sin2 2θ)=(2.0×10(-3)  eV2, 1.0) and is consistent with the overall Super-K measurement.

Intracellular glutathione redox status in human dendritic cells regulates IL-27 production and T-cell polarization

BACKGROUND

Glutathione redox status, changes in intracellular reduced (GSH) or oxidized (GSSG) glutathione, plays a significant role in various aspects of cellular function. In this study, we examined whether intracellular glutathione redox status in human dendritic cells (DCs) regulates the polarization of Th1/Th2 balance.

METHODS

Human monocyte-derived DCs (MD-DCs) treated with glutathione reduced form ethyl ester (GSH-OEt) or L-buthionine-(S,R)-sulfoximine (BSO) were stimulated by lipopolysaccharide (LPS), and the levels of polarization cytokines were measured. Next, DCs matured by LPS or thymic stromal lymphopoietin (TSLP) were cocultured with allogeneic CD4(+) naive T cells and Th1/Th2 balance was evaluated by cytokine production from the primed T cells.

RESULTS

Monocyte-derived DCs exposed to GSH-OEt and BSO had increased and decreased intracellular GSH contents, respectively. Lipopolysaccharide-induced interleukin (IL)-27 production was enhanced by GSH-OEt and suppressed by BSO, but neither GSH-OEt nor BSO affected the expression of HLA-DR, CD80, CD83, or CD86. Mature GSH-OEt-treated MD-DCs enhanced interferon (IFN)-γ production from CD4(+) T cells compared with nontreated MD-DCs, and small interfering RNA (siRNA) against IL-27 suppressed the effect of GSH-OEt on IFN-γ production. Additionally, although human myeloid DCs activated by TSLP (TSLP-DCs) prime naïve CD4(+) T cells to differentiate into Th2 cells, treatment of TSLP-DCs with GSH-OEt reduced IL-13 production and enhanced IFN-γ production by CD4(+) T cells. Interleukin-27 siRNA attenuated the inhibitory effect of GSH-OEt on Th2 polarization.

CONCLUSION

Our results reveal that Th1 and Th2 responses are controlled by intracellular glutathione redox status in DCs through IL-27 production.

Mismatch recognition in PNA double-duplex invasion

Double-duplex invasion of pseudo-complementary PNA (pcPNA) to double-stranded DNA is promising for recognition of a specific sequence in double-stranded DNA. In order to apply this process for various purposes such as gene suppression, one base-pair change at the target site in DNA must be strictly distinguished by the pcPNA additives. In this study, mismatch-recognizing activity of double-duplex invasion was investigated under various salt conditions. It has been found that the mismatch-recognition of the invasion is strict enough to distinguish one base-pair alternation, as long as the invasion is achieved in the media of appropriate ionic strength (e.g., [NaCl] = 20 mM).

Single-strand binding protein enhances invasion of a PNA strand to double-stranded DNA

We show that, in the presence of single-strand binding protein (SSB), one strand of peptide nucleic acid (PNA) efficiently invades double-stranded DNA (dsDNA) in sequence-specific manner, as shown in Figure 1. In the absence of SSB, this kind of strand invasion never occurs. This significant enhancement of invasion can be applied to in vivo applications.

A U-tetrad stabilizes human telomeric RNA G-quadruplex structure

Telomeric repeat-containing RNA is a new noncoding RNA molecule recently discovered in mammalian cells. Here we report the structural features of human telomere RNA r(UAGGGU) in the presence of K(+) and Na(+). We demonstrated for the first time that a novel U-tetrad is formed at the 3' end of a parallel human telomeric RNA G-quadruplex. The U-tetrad dramatically stabilizes human telomeric RNA G-quadruplex structure, leading to an increase in melting temperature (T(m)) of 29 degrees C. The U-tetrad-stabilized telomeric RNA G-quadruplex structure adds considerably to our understanding of the diversity of RNA G-quadruplex architectures. It shows that the structure of base "quartets" is important in RNA assembly. The structural information will be invaluable for understanding the function of human telomere RNA.

Mechanism of gastroesophageal reflux in patients with obstructive sleep apnea syndrome

BACKGROUND

It has been reported that the prevalence of gastroesophageal reflux (GER) disease is high in patients with obstructive sleep apnea (OSA). End-inspiratory intra-esophageal pressure decreases progressively during OSA, which has been thought to facilitate GER in OSA patients. The aim of our study was to clarify the mechanisms of GER during sleep (sleep-GER) in OSA patients.

METHODS

Eight OSA patients with reflux esophagitis (RE), nine OSA patients without RE, and eight healthy controls were studied. Polysomnography with concurrent esophageal manometry and pH recording were performed.

KEY RESULTS

Significantly more sleep-GER occurred in OSA patients with RE than without RE or in controls (P < 0.05). The severity of OSA did not differ between OSA patients with RE and without RE. Sleep-GER was mainly caused by transient lower esophageal sphincter relaxation (TLESR), but not by negative intra-esophageal pressure during OSA. During OSA gastroesophageal junction pressure progressively increased synchronous to intra-esophageal pressure decrease. OSA patients had significantly more TLESR events during sleep related to preceding arousals and shallow sleep, but the number of TLESR events was not related to RE.

CONCLUSIONS & INFERENCES

In OSA patients, sleep-GER was mainly caused by TLESR, but not by negative intra-esophageal pressure due to OSA.

Promotion of strand invasion by utilizing entropically-favored PNA

Invasion of peptide nucleic acid (PNA) is important to target a specific site in double-stranded DNA. However, it needs improvement in many ways such as sequence versatility and invasion efficiency. It is here reported that one 10-mer strand of alpha-lysine substituted peptide nucleic acid (PNA) efficiently invades double-stranded DNA (dsDNA) in the presence of single-strand binding protein (SSB) via Watson-Crick rule. According to the thermodynamic parameters in this study, highly efficient invasion was achieved by a favorable entropy change. The importance of preorganization of PNAs for efficient strand invasion is indicated.

Analysis on the co-localization of asbestos bodies and Fas or CD163 expression in asbestos lung tissue by in-air micro-pixe

To prevent and control disease caused by exposure to various agents, it is necessary to determine the harmful level of intervention and to establish a method for measuring that level. In-air microparticle-induced X-ray emission (in-air micro-PIXE) analysis is based on irradiation of specimens with a proton ion microbeam, and has been modified for biological application. Two-dimensional analysis and quantitative analysis using the system confirmed that asbestos induced apoptosis by upregulating Fas expression and also revealed the accumulation of CD163-expressing macrophages in the lungs of patients with asbestosis. By quantitative comparison of the area of Fas or CD163 expression and the Fas- or CD163-negative area in asbestos lung tissue, the harmful levels which caused the expression of Fas or CD163 could be estimated on Silica, Ferrous iron, and Magnesium (the components of asbestos) deposition. These results indicate that the system could be useful for investigating the pathogenesis of inhaled particle-induced immune reactions and for determining harmful levels of exogenous agents.

Clinicopathological and therapeutic significance of CXCL12 expression in lung cancer

Interactions between CXCL12 and its receptors CXCR4 or CXCR7 are involved in tumor growth and metastasis in various types of human cancer. However, CXCL12 expression and its role in lung cancer are not fully elucidated. Here we examined the expression of CXCL12 in 54 lung cancer cell lines consisting of 23 small cell lung cancers (SCLCs) and 31 non-small cell lung cancers (NSCLCs). CXCL12 was overexpressed in lung cancer cell lines compared to non-malignant human bronchial epithelial cell lines (N = 6). CXCL12 expression was positively but weakly correlated with the expression of CXCR4 or CXCR7. We also examined CXCL12 expression in 89 NSCLC specimens and found that CXCL12 expression was significantly higher in tumor specimens from female patients, non-smokers and adenocarcinoma patients. Small interfering RNAs targeting CXCL12 inhibited cellular proliferation, colony formation and migration of CXCL12-overexpressing lung cancer cells; however, this inhibition did not occur in lung cancer cells that lacked CXCL12. Furthermore, the anti-CXCL12 neutralizing antibody mediated inhibitory effects in three lung cancer cell lines that overexpressed CXCL12, but not in two CXCL12 non-expressing lung cancer cell lines nor two non-malignant bronchial epithelial cell lines. The present study demonstrates that: CXCL12 is concomitantly overexpressed with CXCR4 or CXCR7 in lung cancers; CXCL12 is highly expressed in NSCLCs from females, non-smokers and adenocarcinoma patients; and disruption of CXCL12 inhibits the growth and migration of lung cancer cells. Our findings indicate that CXCL12 is required for tumor growth and provide a rationale for the anti-CXCL12 treatment strategy in lung cancer.

Decreased Interstitial FOXP3+ Lymphocytes in Usual Interstitial Pneumonia with Discrepancy of CXCL12/CXCR4 Axis

Regulatory T cells (Treg) play a critical role in immune homeostasis and expansion of Treg is controlled by chemokine receptors. The chemokine CXCL12 and its G-protein-coupled receptor (CXCR4) are involved in the development of idiopathic pulmonary fibrosis (IPF), but the association of Treg with the CXCL12/CXCR4 axis has not been documented. The aim of this study is to determine the distribution and extent of CXCL12/CXCR4 expression in idiopathic type of pulmonary fibrosis, and the relation of Treg expansion in the interstitium of pulmonary fibrosis patients to CXCL12/CXCR4 expression. CXCL12 expression was examined by immunostaining and ELISA in tissue specimens from patients with usual interstitial pneumonia (UIP, n=15), patients with fibrotic non-specific interstitial pneumonia (f-NSIP, n=4), and controls (n=6). CXCR4 expression was examined by in situ hybridization and immunoblotting. Expression of CD45, CD3, CD20, transcription factor forkhead box P3 (FOXP3), and CD25 was assessed by immunostaining. Fibrosis was evaluated by determining the established fibrosis (EF) score. The CXCL12/CXCR4 axis was upregulated in UIP and f-NSIP, and CXCL12 derived from lung tissue attracted CXCR4+ cells. CXCR4+ cells showed a CD3+ cell distribution pattern. The interstitial FOXP3+/CD3+ and CD25+/CD3+ cell ratios were lower in UIP than f-NSIP, but the CXCR4+/ CD3+ cell ratio was not different. The FOXP3+/CD3+ cell ratio and EF score were inversely correlated. These findings suggest that the CXCL12/CXCR4 axis contributes to inflammation in UIP and f-NSIP by promoting the accumulation CXCR4+ lymphocytes, and a decrease of Treg is correlated with the severity of fibrosis in UIP.

Eosinophilic bronchiolitis indicating eosinophilic airway disease with overexpression of carcinoembryonic antigen in sinus and bronchiole: case report

The present case showed eosinophilic bronchiolitis and sinusitis with an overexpression of carcinoembryonic antigen (CEA) in lung and sinus and an elevation of serum CEA level, both of which were improved by oral steroid therapy. A 54-year-old asthmatic woman had developed a shortness of breath on exertion, and the chest X-ray revealed diffuse centrilobular shadows. Her serum CEA level had increased gradually. Eosinophil infiltration and overexpression of CEA were demonstrated in both the lung and sinus by immunohistochemistry. Both the lung and sinus lesions, and the serum CEA level were improved by oral steroid therapy. No evidence of tumor was found by extensive examination. From this case, eosinophilic bronchiolitis was considered to be an airway disease like "eosinophilic sinobronchiolitis" through the common pathophysiology of CEA, and serum CEA level was a good marker of disease condition.

[Mucinous bronchiolo-alveolar cell carcinoma with marked serum elevation of CA19-9: report of a case]

An 83-year-old woman was referred to our hospital to examine for an infiltration shadow in the right lower lobe with progressive bronchorea Computed tomography showed an infiltration lesion with the longest diameter of 10 cm in the right lower lobe and a tumor with the longest diameter of 3 cm in the middle lobe. Serum level of carbohydrate antigen (CA) 19-9 markedly increased to 37,670 U/ml over a period of 3 months. The pathologic study obtained by a transbronchial tumor biopsy revealed a mucinous adenocarcinoma The patient underwent video-assisted thoracoscopic right middle and lower bi-lobectomies with nodal sampling. Postoperative course was uneventful Pathologic study revealed an adenocarcinoma with mixed subtypes, predominantly composed of mucinous bronchiolo-alveolar cell carcinoma (BAC). Immunohistochemical study showed CA19-9 positivity in the apical surface of some tumor cells and diffuse patterns of other tumor cells. Postoperative course was uneventful and serum CA19-9 levels decreased within the normal range. Clinico-pathologic features of the lung cancer patients with serum elevation of CA19-9 and CA19-9 positivity in the cancer cells was discussed. CA19-9 can be an useful tumor marker in the selected patients with mucinous BAC.

Origin of high fidelity in target-sequence recognition by PNA-Ce(IV)/EDTA combinations as site-selective DNA cutters

Double-duplex invasion of pseudocomplementary peptide nucleic acid (pcPNA) is one of the most important strategies for recognizing a specific site in double-stranded DNA (Proc. Natl. Acad. Sci. U.S.A. 1999, 96, 11804-11808). This strategy has recently been used to develop artificial restriction DNA cutters (ARCUTs) for site-selective scission of double-stranded DNA, in which a hot spot formed by double-duplex invasion of PNA was hydrolyzed by Ce(IV)/EDTA (Nat. Protoc. 2008, 3, 655-662). The present paper shows how and where the target sequence in double-stranded DNA is recognized by the PNA-Ce(IV)/EDTA combinations for site-selective scission. The mismatch-recognizing activities in both the invasion process and the whole scission process are evaluated. When both pcPNA additives are completely complementary to each strand of the DNA, site-selective scission is the most efficient, as expected. Upon exchange of one DNA base pair at the invasion site with another base pair, which introduces mismatches between the pcPNAs and the DNA, the site-selective scission by the ARCUT is notably diminished. Mismatches in (or near) the central double-invasion region are especially fatal, showing that Watson-Crick pairings of the DNA bases in this region with the pcPNA strands are essential for precise recognition of the target sequence. Both gel-shift assays and melting temperature measurements on the double-duplex invasion process have confirmed that the fidelity in this process primarily governs the fidelity of the DNA scission. According to these systematic analyses, the typical ARCUT involving two 15-mer pcPNAs precisely recognizes 14-16 base pairs in substrate DNA. This remarkable fidelity is accomplished at rather high salt concentrations that are similar to the values in cells.

Search for proton decay via p-->e+pi0 and p-->micro+pi0 in a large water Cherenkov detector

We have searched for proton decays via p-->e;{+}pi;{0} and p-->micro;{+}pi;{0} using data from a 91.7 kt.yr exposure of Super-Kamiokande-I and a 49.2 kt.yr exposure of Super-Kamiokande-II. No candidate events were observed with expected backgrounds induced by atmospheric neutrinos of 0.3 events for each decay mode. From these results, we set lower limits on the partial lifetime of 8.2 x 10;{33} and 6.6 x 10;{33} years at 90% confidence level for p-->e;{+}pi;{0} and p-->micro;{+}pi;{0} modes, respectively.

Acute antibody-mediated rejection in living ABO-incompatible kidney transplantation: long-term impact and risk factors

The impact of acute antibody-mediated rejection (AAMR) on the long-term outcome on ABO-incompatible (ABOI) kidney transplantation is not well understood. We retrospectively analyzed the long-term impact of AAMR and risk factors for AAMR in 57 consecutive recipients performed between 1999 and 2004. Nineteen patients (33%) who developed AAMR within 3 months posttransplantation constituted of the AMR group. The graft survival rate was significantly lower in the AMR group (AMR vs. non-AMR, respectively; 5 years: 84% vs. 95%; 8 years: 45% vs. 95%; p = 0.009). The prevalence of transplant glomerulopathy at 1 year posttransplantation was significantly higher in the AMR group (AMR 64% vs. non-AMR 3%, p < 0.001). Multivariate analysis demonstrated that anti-blood group IgG antibody titers of 1:32 at the time of transplantation (OR, 9.52; p = 0.041) and donor-specific anti-HLA antibodies (DSHA) detected by Luminex single bead method (OR, 5.68; p = 0.015) were independent risk factors for AAMR regardless of baseline anti-blood group IgG antibody titers. Our results indicate that AAMR has a heavy impact on the long-term outcome and preoperative DSHA appears to have a more significant association with poor graft outcomes than anti-blood group antibodies, even in ABOI kidney transplantation.

Strand invasion of conventional PNA to arbitrary sequence in DNA assisted by single-stranded DNA binding protein

In the presence of single-stranded DNA binding protein (SSB), conventional peptide nucleic acid (PNA) without chemical modifications efficiently invades into arbitrary sequences in DNA.

Experimental evaluation of photocrosslinkable chitosan hydrogel as injection solution for endoscopic resection

BACKGROUND AND STUDY AIMS

Saline as an injection solution for endoscopic resection techniques has several disadvantages such as a short-lasting effect leading to a potentially higher risk of bleeding and perforation. The new substance of photocrosslinkable chitosan hydrogel in a DMEM/F12 medium (PCH) can be converted into an insoluble hydrogel by ultraviolet irradiation for 30 s, and was evaluated in two sets of animal experiments.

METHODS

18 pigs were used in the two parts of the study. First, mucosal resections were done with either PCH or hypertonic saline; the effects of both agents on wound healing were examined endoscopically and histologically. Second, in vivo degradation of PCH was examined using six pig stomachs.

RESULT

PCH injection led to a longer-lasting elevation with clearer margins, compared with hypertonic saline, thus enabling precise endoscopic submucosal dissection (ESD) along the margins of the elevated mucosa. The endoscopic appearance after ESD was similar in both groups. PCH biodegradation was completed within 8 weeks according to endoscopic and histologic analyses.

CONCLUSION

PCH is a promising agent for submucosal injection prior to various techniques of endoresection. It should be evaluated in clinical trials after biocompatibility testing for PCH is completed.

CXCR4+FOXP3+CD25+ Lymphocytes Accumulate in CXCL12-Expressing Malignant Pleural Mesothelioma

CXCL12 is a chemokine that binds to a G-protein-coupled receptor (CXCR4). CXCL12 is expressed in various tumors and is considered as playing an important role in tumor growth and invasion. The aim of this study is to investigate the expression of CXCL12 in human malignant mesothelioma (MM), the chemotactic effect of CXCL12 derived from MM, and the expression of CXCR4 in MM tissues in relation to regulatory T cells. CXCL12 expression was examined by immunostaining of tissue specimens from malignant pleural mesothelioma (MPM) and malignant peritoneal mesothelioma (MPEM). The MM group comprised 6 patients (4 men/2 women, MPM=4, MPEM=2, aged 56.0 ± 12.4 years) and the control (non-mesothelioma) group also had 6 patients (4 men/2 women aged 65.0 ± 6.7 years). CXCL12 mRNA expression was also examined by RT-PCR in MPM cell lines (H28, H2052, and H2058), while CXCR4 mRNA expression was examined by in situ hybridization in MPM tissue. CXCL12 was expressed in the cytoplasm of MM cells from all patients, but was not expressed in the control group. H2052 and H2058 cells expressed CXCL12 mRNA, but H28 cells did not. CXCL12 in MM tissue homogenate supernatant had a chemotactic effect on CXCR4-expressing THP-1 cells. CXCR4 mRNA was expressed by a part of LCA+CD3+ Foxp3+CD25+ T cells that were located adjacent to the border of CXCL12-expressing epithelioid MPM. These findings suggest that CXCL12 contributed to tumor-related inflammation by inducing the accumulation of CXCR4-expressing cells with regulatory T cell markers around MM.

Solid-phase synthesis of pseudo-complementary peptide nucleic acids

Pseudo-complementary peptide nucleic acid (pcPNA) is a DNA analog in which modified DNA bases 2,6-diaminopurine (D) and 2-thiouracil (U(s)) 'decorate' a poly[N-(2-aminoethyl)glycine] backbone, together with guanine (G) and cytosine (C). One of the most significant characteristics of pcPNA is its ability to effect double-duplex invasion of predetermined DNA sites inducing various changes in the biological and the physicochemical properties of the DNA. This protocol describes solid-phase synthesis of pcPNA. The monomers for G and C are commercially available, but the monomers for D and U(s) need to be synthesized (or can be ordered to custom synthesis companies). Otherwise, the procedure is the same as that employed for Boc-strategy synthesis of conventional PNA. This protocol, if the synthesis of D and U(s) monomers is not factored in, takes approximately 7 d to complete.

Hypoxemia with high alveolar-arterial oxygen gradient but no lung involvement in a patient with Churg-Strauss syndrome: case report

Churg-Strauss syndrome (CSS) is characterized by asthma and/or a history of allergy, eosinophilia and an often life-threatening systemic necrotizing vasculitis. We describe a patient with CSS and hypoxemia with a high alveolar-arterial oxygen gradient (AaDO2), but no pulmonary parenchymal involvement. The patient also had a low diffusion capacity with normal lung volume and a high level of serum thrombomodulin, a marker of endothelial cell injury. Treatment for CSS, such as corticosteroid, improved both hypoxemia and AaDO2 consistent with amelioration of diffusion capacity and serum thrombomodulin level, suggesting that this pathosis involves microangiopathy with endothelial cell damage induced by vasculitis in pulmonary blood vessels.

Chiral introduction of positive charges to PNA for double-duplex invasion to versatile sequences

Invasion of two PNA strands to double-stranded DNA is one of the most promising methods to recognize a predetermined site in double-stranded DNA (PNA = peptide nucleic acid). In order to facilitate this 'double-duplex invasion', a new type of PNA was prepared by using chiral PNA monomers in which a nucleobase was bound to the alpha-nitrogen of N-(2-aminoethyl)-d-lysine. These positively charged monomer units, introduced to defined positions in Nielsen's PNAs (poly[N-(2-aminoethyl)glycine] derivatives), promoted the invasion without impairing mismatch-recognizing activity. When pseudo-complementary nucleobases 2,6-diaminopurine and 2-thiouracil were bound to N-(2-aminoethyl)-d-lysine, the invasion successfully occurred even at highly G-C-rich regions [e.g. (G/C)7(A/T)3 and (G/C)8(A/T)2] which were otherwise hardly targeted. Thus, the scope of sequences available as the target site has been greatly expanded. In contrast with the promotion by the chiral PNA monomers derived from N-(2-aminoethyl)-d-lysine, their l-isomers hardly invaded, showing crucial importance of the d-chirality. The promotion of double-duplex invasion by the chiral (d) PNA monomer units was ascribed to both destabilization of PNA/PNA duplex and stabilization of PNA/DNA duplexes.

Prognostic significance of L-type amino acid transporter 1 expression in resectable stage I-III nonsmall cell lung cancer

The clinical significance of L-type amino acid transporter 1 (LAT1) expression remains unclear, whereas many experimental studies have demonstrated that LAT1 is associated with the proliferation of cancer cells. The purpose of this study was to evaluate the prognostic value of LAT1 in patients with nonsmall cell lung cancer (NSCLC). A total of 321 consecutive patients with completely resected pathologic stage I–III NSCLC were retrospectively reviewed. Expression of LAT1 and proliferative activity, as determined by the Ki-67 labelling index, was also evaluated immunohistochemically and correlated with the prognosis of patients who underwent complete resection of the tumour. Expression of LAT1 was positive in 163 patients (51%) (29% of adenocaricnoma (58 of 200 patients), 91% of squamous cell carcinoma (91 of 100 patients), and 67% of large cell carcinoma (14 of 21 patients)). The 5-year survival rate of LAT1-positive patients (51.8%) was significantly worse than that of LAT1-negative patients (87.8%; P<0.001). L-type amino acid transporter 1 expression was significantly associated with lymph node metastasis and disease stage. Multivariate analysis confirmed that positive expression of LAT1 was an independent factor for predicting a poor prognosis. There was a significant correlation between LAT1 expression and Ki-67 labelling index. LAT1 expression is a promising pathological factor to predict the prognosis in patients with resectable stage I–III NSCLC.

The relationship between oxidative stress and acid stress in adult patients with mild asthma

BACKGROUND

Oxidative stress plays an important role in the pathogenesis of asthma. Interestingly, a low airway pH and a high concentration of 8-isoprostane, a marker of oxidative stress, has been reported to cause inflammatory airway diseases. However, the relationship between these 2 markers and pulmonary function has not been determined in mild asthma patients.

METHODS

pH and 8-isoprostane concentration were measured in exhaled breath condensate (EBC) from patients with mild asthma (n = 44) and healthy subjects (n = 20). The relationship between acid stress (pH) and oxidative stress (8-isoprostane) was then analyzed, along with the relationships between these 2 markers and lung function.

RESULTS

The median (interquartile range [IQR]) pH of EBC was significantly lower in asthma patients than in control subjects (7.53 [7.41-7.68] vs 7.70 [7.62-7.74], P < .05), while the median (IQR) 8-isoprostane concentration of EBC was significantly higher in asthma patients than control subjects (16.2 [11.7-19.1] vs 3.5 [2.6-7.9] pg/mL, P < .05). There was no correlation between pH and 8-isoprostane concentration. Furthermore, lung function was not correlated with either pH or 8-isoprostane concentrations in EBC.

CONCLUSIONS

Acid stress and oxidative stress assessed by pH and 8-isoprostane concentration, respectively, in EBC did not show parallel changes associated with asthma and were not correlated with lung function in asthma patients. These 2 stress factors may have different roles in the pathogenesis of asthma.

Acute impact of volcanic ash on asthma symptoms and treatment

Information about the impacts of disasters on health is useful for establishing hazard prediction maps and action plans of disaster management. This study aims at learning effective asthma management from the volcano disaster of Mount Asama eruption in Japan on September 1, 2004. We conducted a cross-sectional study to assess the acute impact of volcanic ash on asthma symptoms and their treatment changes by using a questionnaire completed by 236 adult asthmatic patients and their physicians. In the ashfall over 100g/m2 area, 42.9 percent of asthma patients suffered exacerbations, PEF decreased, asthma treatments increased, and inhalation of beta2 stimulants was used most for exacerbated asthma. Compared to severe asthma patients, mild and moderate asthma patients were most at risk. Severe asthma patients were not affected since most of them knew their asthma status was severe, and did not go outside and kept windows closed. Deteriorated asthma symptoms of wheezing, chest tightness and cough appeared in the ashfall over 100g/m2 area. Ash contained inhalable 10microm diameter particles, and included high concentrations of airway toxic substrates of silica. These data suggest that ashfall over 100 g/m2 is harmful, access to these areas by asthma patients needs to be restricted, and these areas need to improve asthma treatment. In addition, the increase in the proportion of asthma patients with wheeze and cough are diagnostic clues for ash-induced asthma in affected areas, and can be used by doctors to tell whether patients are receiving sufficient asthma treatment.

Pseudomesotheliomatous adenocarcinoma of the lung with synchronous gastric and esophageal cancer

Pseudomesotheliomatous adenocarcinoma is an uncommon variant of peripheral lung cancer. This condition mimics a malignant mesothelioma in terms of its clinical presentation and its gross and microscopic appearance. An immunohistochemical investigation is important when it is difficult to determine whether diffuse carcinomatous involvement of the pleura is secondary to metastasis, lung cancer, or mesothelioma. We herein report a very rare case of concomitant pseudomesotheliomatous adenocarcinoma, gastric cancer and esophageal cancer.

Inhibitory effect of glyburide on thrombin-induced platelet aggregation and phosphoinositide metabolism in normal human platelets

We previously reported the effects of diet, sulphonylureas or insulin on thrombin-induced platelet aggregation, phosphoinositide metabolism and protein phosphorylation in non-insulin-dependent diabetes mellitus (NIDDM) patients. To clarify the mechanism of glyburide and insulin on platelet function, here we studied the in vitro effects of glyburide and insulin on thrombin-induced metabolic changes using normal human platelets. Platelet aggregation stimulated with <0.5 U/ml thrombin, 0.75-3 microM adenosine diphosphate (ADP) or 1 microg/ml collagen was significantly lower in glyburide-treated platelets, but not in insulin-treated platelets, than in untreated ones (control). Thrombin-induced incorporation of 32P radioactivity into phosphatidic acid (PA) in glyburide-treated platelets was lower than that in control but not in insulin-treated platelets. Phosphorylated proteins of platelets induced by thrombin and 12- O -tetradecanoylphorbol 13-acetate (TPA) in glyburide-treated platelets were suppressed, but not in insulin-treated platelets, compared with control. These results suggest that glyburide induces suppression of thrombin-induced activation of phospholipase C, which mediates hydrolysis of PIP and PIP(2) and production of PA, and subsequently inhibits platelet aggregation.

Submucosal injection, for endoscopic mucosal resection, of photocrosslinkable chitosan hydrogel in DMEM/F12 medium

BACKGROUND AND STUDY AIMS

We studied the ability of a photocrosslinkable chitosan in DMEM/F12 medium to maintain submucosal thickness and to reduce bleeding after mucosal resection. We also investigated the behavior of chitosan hydrogels with regard to wound healing.

METHODS

The gastric submucosal layer of heparinized rats was injected with the photocrosslinkable chitosan in medium (which was then irradiated with ultraviolet light to form a hydrogel), or with sodium hyaluronate, or hypertonic saline, and three investigations were done, using three different sets of rats. The first and second were measurement of the thickness of the layer, and of the amount of bleeding induced by mucosal resection, respectively. Thirdly, the effects of the chitosan hydrogel on wound healing were examined histologically.

RESULTS

Gastric submucosal layers of chitosan hydrogel-treated animals remained significantly thicker than those of other groups for at least 6 h after injection. The total amount of bleeding 20 min after mechanical mucosal resection was 170.0 +/- 20.0 mg, 678.3 +/- 226.3 mg, and 1020.0 +/- 104.1 mg in the chitosan hydrogel, sodium hyaluronate, and hypertonic saline groups, respectively. Histological study revealed that the focus of bleeding was surrounded by chitosan hydrogel and that almost all the hydrogel was biodegraded within 4 weeks. Furthermore, a discernible, but not statistically significant effect of the chitosan hydrogel on wound healing was observed.

CONCLUSIONS

The chitosan hydrogel produced mucosal elevation after submucosal injection with ultraviolet irradiation, and it significantly reduced bleeding after mucosal resection. Our newly developed chitosan hydrogel in medium might be a promising submucosal agent for endoscopic mucosal resection.