Pretreatment with buthionine sulfoximine enhanced uptake and retention of BSH in brain tumor

To determine the influence of buthionine sulfoximine (BSO) on boron biodistribution after sulfhydryl borane (BSH) administration for boron neutron capture therapy, the effectiveness of the combination of BSO with sulfhydril- (BSH) and non-sulfhydril (B12H12 and BNH3) boron compounds, and the interval between BSO and BSH administration, the retention of boron in tissues have been evaluated using a 9L rat tumor model. Simultaneous administration of BSH and BSO showed significantly higher boron accumulation compared to that without BSO, however there was no difference in tissue boron level between B12H12 and BNH3 administration with BSO or without BSO. The longer interval (6h) between BSH and BSO administration related to the highest boron concentration in the brain and subcutaneous tumors compared to shorter intervals (0.5, 3h). Boron concentration in subcutaneous and brain tumors was maintained for 6 and 12h after the administration of BSH following BSO pretreatment.

Molecular structural analysis of major outer membrane protein (MOMP) gene clusters in Campylobacter lari

Southern hybridisation shows that urease-negative (UN) Campylobacter lari JCM2530(T) carries two putative major outer membrane protein (MOMP) genes. Sequences of approximately 2.1 kbp, encoding non-coding (NC) regions, with possible open reading frames (ORFs) for MOMP (porA1 or porA2) of approximately 1.2 kbp, NC regions and partial and putative Cla_0435 or Cla_1109 ORFs were identified in all five UN C. lari isolates examined, following polymerase chain reaction (PCR) cloning and sequencing. Each putative MOMP structural gene carried start and stop codons and ribosome binding sites of 1236-1278 bp in length. The putative sigma70 transcriptional promoter and the hypothetical rho-independent transcription terminator structures were also seen. Using Northern hybridisation, there was in vivo monocistronic MOMP gene transcription. In addition, in a Japanese urease-positive thermophilic Campylobacter (UPTC) CF89-12 strain, the porA1 gene locus, including an extra gene (approximately 2000 bp in length) was identified. The extra gene may occur within the porA1 gene locus in the eight UPTC isolates of the 23 C. lari isolates examined. Thus, a genetic heterogeneity occurred within the porA1 gene locus from some of the C. lari organisms including the UPTC CF89-12.

Molecular cloning and characterisation of the methionine sulphoxide reductase A (msrA) gene locus in Campylobacter lari organisms

The methionine sulphoxide reductase A (msrA) gene and its adjacent genetic loci from urease-negative (UN) Campylobacter lari RM2100 and urease-positive thermophilic Campylobacter (UPTC)CF89-12 strains appear to be composed of a msrA structure gene (507 base pairs [bp]) and another five-gene cluster (approximately 6300 bp) in the same strand and direction. A primer pair (F1/R4-msrA) for polymerase chain reaction (PCR) amplification was designed to generate a product of approximately 900 bp of the msrA gene, including its adjacent genetic loci for the thermophilic Campylobacter organisms and generate an amplicon with 16 C. lari isolates (n = 4 for UN C. lari; n = 12 for UPTC). Following direct nucleotide sequencing, sequence analysis and nucleotide sequence alignment analysis, the putative full-length msrA gene from the 16 C. lari isolates showed high nucleotide sequence similarities (91.8-100%) to each other and relatively low similarity (69.3-71.8%) to three reference C. jejuni and C. coli strains. In addition, the msrA gene was transcribed in both the UPTC CF89-12 and NCTC12893 cells using reverse transcription PCR. An immunoreactively positive signal was identified in the UPTC CF89-12 and NCTC12893 cells with anti-UPTC MsrA synthetic peptide antibodies.

Competition between antiferromagnetism and ferromagnetism in Sr2RuO4 probed by Mn and Co doping

Spin-triplet superconductivity in Sr₂RuO₄ has attracted enormous interest. Like other unconventional superconductors, superconductivity in Sr₂RuO₄ is in close proximity to magnetic instability. Undoped Sr₂RuO₄ exhibits incommensurate antiferromagnetic (AFM) fluctuations, which can evolve into static, short-range AFM order via Ti doping. Moreover, weak ferromagnetic (FM) coupling in Sr₂RuO₄ has also been suggested by NMR/neutron scattering experiments and studies on Ca_2−xSr_xRuO₄ and Sr_2−yLa_yRuO₄, implying orbital dependent magnetism. We report bulk static, short-range FM order in Sr₂RuO₄ triggered by <2% Co doping, showing superconductivity in Sr₂RuO₄ is much closer to FM instability than previously reported in Ca_2−xSr_xRuO₄. We also find Mn doping can effectively establish incommensurate AFM order, with T_N ~ 50 K for 3% Mn doping. These new results place Sr₂RuO₄ in a unique situation where superconductivity lies directly on the borderline of two distinct magnetic states, highlighting the important role of competing magnetic fluctuations in determining superconducting properties of Sr₂RuO₄.

Prospects for using a hemoconcentrator as an alternative hemodialysis method in cardiopulmonary bypass surgeries

Objective:

Cardioplegic solutions often cause high blood concentrations of potassium. The conventional hemoconcentration circuit was improved to correct electrolyte imbalances through a method involving dilutional ultrafiltration (DUF) and an alternative hemodialysis (ALTHD) method. This study aimed to determine the effectiveness of this ALTHD method.

Methods:

Bovine blood was used, in conjunction with a hemoconcentrator, in an experimental hemodialysis (HD) circuit to evaluate an ALTHD method. The effectiveness of the method was determined by electrolyte and hematocrit measurements following the procedure.

Results:

The ALTHD method corrected electrolyte levels as effectively as DUF and was less affected by dilution than DUF.

Conclusion:

The ALTHD method may provide faster electrolyte adjustments than DUF because its efficiency depends on both the blood and dialysate flow rates. In addition, the ALTHD method is expected to provide increased efficiency. Thus, our DUF/ALTHD circuit-switching method may be clinically useful when rapid electrolyte correction is required.

Construction, expression and characterisation of recombinant molecules of the urease gene operon from a urease-positive thermophilic Campylobacter (UPTC) isolate

A recombinant molecule of the full-length urease gene operon was constructed in vitro from the Japanese urease-positive thermophilic Campylobacter (UPTC) CF89-12 isolate and expressed in Escherichia coli cells. Several large deletion recombinant variants of urease subunit genes were also constructed and expressed in E. coli cells. A positive urease reaction with the log-phase cultured E. coli JM109 cells in the NiCl2-containing medium transformed with pGEM-T vector carrying the recombinant molecule of the full-length operon was detected with isopropyl-beta-D-thiogalactoside. Among the several deletion recombinant variants, each ureA-, ureB-, ureE-, ureF-, ureG- and ureH-large deficient, only ureE-large deletion variant (63% deficient) showed a positive urease reaction (approximately 15-fold). In addition, a ureE-complete deletion recombinant variant (100% deficient) constructed also showed a positive reaction of urease (approximately 18-fold). Recombinant urease subunits A and B were immunologically identified by Western blot analysis with anti-urease alpha (A) and beta (B) raised against Helicobacter pylori.

Effect of electron correlations on magnetic excitations in the isovalently doped iron-based superconductor Ba(Fe(1-x)Ru(x))(2)As(2)

Magnetic correlations in isovalently doped Ba(Fe(1-x)Ru(x))(2)As(2) (x = 0.25, T(c) = 14.5 K; x = 0.35, T(c) = 20 K) are studied by elastic and inelastic neutron scattering techniques. A relatively large superconducting spin gap accompanied by a weak resonance mode is observed in the superconducting state in both samples. In the normal state, the magnetic excitation intensity is dramatically reduced with increasing Ru doping toward the optimally doped regime. Our results favor that the weakening of the electron-electron correlations by Ru doping is responsible for the dampening of the resonance mode, as well as the suppression of the normal state antiferromagnetic correlations near the optimally doped regime in this system.

Molecular identification of an arsenic four-gene operon in Campylobacter lari

An arsenic (ars) four-gene operon, containing genes encoding a putative membrane permease (ArsP), a transcriptional repressor (ArsR), an arsenate reductase (ArsC) and an arsenical-resistance membrane transporter (Acr3) was first identified in urease-positive thermophilic Campylobacter (UPTC) isolate, CF89-12. UPTC CF89-12 and some other Campylobacter lari isolates contained their ars four-genes, similarly, differing from that in the reference C. lari RM2100 strain. Two putative promoters and a putative terminator were identified for the operon in UPTC CF89-12. In vivo transcription of the operon was confirmed in the UPTC cells. PCR experiments using two primer pairs designed in silico to amplify two arsR and arsC-acr3 segments, respectively, generated two amplicons, approximately 200 and 350 base pairs, with all 31 of 31 and 19 of 31 C. lari isolates (n = 17 for UPTC; n = 14 for UN C. lari), respectively. An inverted repeat forming a dyad structure, a potential binding site for a transcriptional repressor, was identified in the promoter region. Within the deduced 61 amino acids sequence of the putative arsR open reading frame from the UPTC CF89-12, a metal binding box and a DNA-binding helix-turn-helix motif were identified. The UPTC CF89-12 and some other UPTC isolates isolated from natural environment were resistant to arsenate.

Transparent-Scaled Variant of the Rosy Bitterling, Rhodeus ocellatus ocellatus (Teleostei: Cyprinidae)

Transparent-scaled variant (TSV) of the rosy bitterling Rhodeus ocellatus ocellatus (Kner) was observed on both morphology and heredity. Compared with the normal-scaled type (NST), TSV is characterized by the blackish coloration in both eyes and peritoneum, and the luminescent one over the whole body. Histologically, the density of guanophores containing reflecting platelets was conspicuously low, especially in scale, iris, choroid and peritoneum, while the increase in the number of goblet cells (mucous cells) was recognized all over the dermal/epidermal regions. The heredity of TSV was recessive and supposed to be controlled by a single pair of genes unrelated to sex, judging from the result of crossbreeding experiments between NST and TSV. In growth and reproduction, no difference was seen between these two phenotypes. Transparent-scaled variant of the rosy bitterling can be competent for a genetic marker in experimental and developmental biology.

Doxorubicin enhances transient expression of p-glycoprotein and modulates activity and isoform expression of protein-kinase-C in ah66 rat hepatoma-cells

Intracellular changes in enzyme activity and the isoform pattern of protein kinase C (PKC) during treatment with doxorubicin (DXR) were examined in a rat ascites hepatoma AH66 parental cell line (AH66P), which shows slight expression of P-glycoprotein (Pgp) on the cell membrane and is classified as an intrinsic multidrug-resistant cell. AH66P cells, treated for 10 days with DXR at the concentrations of 0.3 or 5.0 muM, exhibited moderate to severe inhibition of PKC activity after transient increase of the activity, which mainly was either Ca2+-independent and phospholipid-dependent or Ca2+-independent and phospholipid-independent. PKC isoform analysis of the treated cells also indicated the transient 1.5- and 1.8-fold increase of PKC-delta and PKC-zeta as well as slight increase of PKC-alpha in treatment with 0.3 muM DXR and 1.9- and 1.6-fold increase of PKC-alpha and PKC-zeta with slight increase of PKC-delta in treatment with 5.0 muM, respectively. A small, but interesting discrepancy between the markedly elevated enzyme activity, which was composed particularly of both cofactor-independent forms, and the relatively low levels of isoform expression, was found when the cells were treated with 5.0 muM DXR. It is of great interest that DXR-treatment, while only slight increasing P-glycoprotein (Pgp) phosphorylation, enhanced the transient expression of Pgp on the cell membrane with good correlation with the fluctuating change in PKC activity. These results indicate that the possible expression of some or novel specific isoform(s) of PKC may modulate and be associated with expression of the Pgp.

Characteristic changes in protein-kinase-C activity and isoforms in ah66 cells during the acquisition of multidrug-resistant phenotype

Changes in enzyme activity and the isoform pattern of protein kinase C (PKC) during the process of acquiring of drug resistance to doxorubicin (DXR) was examined in rat ascites hepatoma AH66 parental cells (AH66P) and several established clones of DXR-resistant AH66DR cells. In the weakly resistant cell line, AH66DR-0.3, which was resistant to DXR at the concentration of 0.3 mu M, reduced PKC activity and significantly decreased expression of its isoforms (alpha, delta and zeta) were observed. By contrast, AH66DR-30, the clone with the highest resistance, showed increased PKC activity, which was mainly either Ca2+-independent and phospholipid-dependent or Ca2+-independent and phospholipid-independent. PKC-isoform analysis of the AH66DR-30 cells disclosed high levels of PKC-delta and -zeta and a quite low level of PKC-alpha relative to that of the AH66P cells. In both cell lines, phosphorylation of P-glycoprotein (Pgp), which is known as a drug efflux pump, was induced by PKC not only with Ca2+-dependent, but also with Ca2+-independent reactions. These results indicate that the expression of one or more specific isoform(s) of PKC, particularly the Ca2+-independent type, may be necessary for expression as well as activation of the function of Pgp.

Ca(2)Y(2)Cu(5)O(10): the first frustrated quasi-1D ferromagnet close to criticality

Ca(2)Y(2)Cu(5)O(10) is built up from edge-shared CuO(4) plaquettes forming spin chains. From inelastic neutron scattering data we extract an in-chain nearest-neighbor exchange J(1)≈-170  K and the frustrating next-neighbor J(2)≈32  K interactions, both significantly larger than previous estimates. The ratio α=|J(2)/J(1)|=0.19±0.01 places the system close to the critical point α(c)=0.25 of the J(1)-J(2) chain but in the 1D ferromagnetic regime. We establish that the vicinity to criticality only marginally affects the dispersion and coherence of the spin-wave-like magnetic excitations but instead results in a dramatic T dependence of high-energy Zhang-Rice singlet excitation intensities.

Mesenteric phlebosclerosis associated with long-term oral intake of geniposide, an ingredient of herbal medicine

BACKGROUND

Idiopathic mesenteric phlebosclerosis (IMP) is a rare disease, characterised by thickening of the wall of the right hemicolon with calcification of mesenteric veins. However, the aetiology remains unknown.

AIM

To investigate the possible association of herbal medicines with IMP.

METHOD

The clinical data of four of our own patients were collected. Furthermore, we searched for previous reports about similar patients with detailed descriptions of herbal prescriptions that they had taken. We compared herbal ingredients to identify the toxic agent as a possible aetiological factor.

RESULTS

Clinical data on a total of 25 patients were summarised. Mean age was 61.8 years and there was female predominance (6 men and 19 women). The used Kampo prescription, the number of cases, and the mean duration of use were as follows: kamisyoyosan in 12 cases for 12.8 years, inshin-iseihaito in 5 cases for 13.4 years, orengedokuto in 4 cases for 14.3 years, inchinkoto in 1 case for 20 years, kamikihitou in 1 case for 19 years, seijobofuto in 1 case for 10 years and gorinsan in 1 case for an unknown duration. Only one ingredient, sansisi, was common to the herbal medicines of all 25 patients. This crude drug called geniposide in English is a major constituent of the Gardenia fruits.

CONCLUSION

The long-term use of geniposide in herbal medicines appears to be associated with mesenteric phlebosclerosis.

magnetic dispersion and anisotropy in multiferroic BiFeO3

We have determined the full magnetic dispersion relations of multiferroic BiFeO3. In particular, two excitation gaps originating from magnetic anisotropies have been clearly observed. The direct observation of the gaps enables us to accurately determine the Dzyaloshinskii-Moriya (DM) interaction and the single ion anisotropy. The DM interaction supports a sizable magnetoelectric coupling in this compound.

Expression and analysis of a cytolethal distending toxin (cdt) gene operon in Campylobacter lari

The present study examines the expression of cytolethal distending toxin (cdt) gene encoding a cytotoxin in Campylobacter lari (n=6 urease-negative [UN] C. lari; n=4 urease-positive thermophilic Campylobacter [UPTC]). When reverse transcription polymerase chain reaction (RT-PCR) was carried out with 10 C. lari isolates using a primer pair to amplify the cdtB gene transcript segment, an approximate 260 bp RT-PCR amplicon was generated with all the isolates. In addition, cdtA, cdtB and cdtC gene operon was identified to be polycistronicly transcribed in the C. lari cells. The cdtB gene translation in the C. lari cells was also confirmed by Western blot analysis. Thus, the cdt gene operon in C. lari organisms, including UN C. lari and UPTC, was expressed at the transcriptional and translational levels in the cells. The present results suggest that all three cdt genes may be functional in the cells.