Quantification of two aromatic amine mutagens, PBTA-1 and PBTA-2, in the yodo river system

The levels of two aromatic amine mutagens, 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)amino]-5-methoxyphenyl]-5-am ino-7-bromo-4-chloro-2H-benzotriazole (PBTA-1) and 2-[2-(acetylamino-4-[N-(2-cyanoethyl)ethylamino]-5-methoxyphenyl]-5-a mino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2), were quantitatively analyzed in the Yodo River system in Japan. The river water samples were collected at nine sampling sites from the Yodo River system twice or three times between May and July in 1997. PBTA-1 and PBTA-2 in the river water samples were concentrated on blue rayon columns, partially purified by high-performance liquid chromatography (HPLC) on reverse-phase columns, then quantified by HPLC with an electrochemical detector. The amounts of PBTA-1 and PBTA-2 in the water samples were < 0.01-1.91 and < 0.01-2.25 ng/L, respectively. High levels of PBTA-1 and PBTA-2 were detected in the samples collected within 4 km downstream of two sewage plants, which are located along the banks of the Nishitakase River, a tributary of the Yodo River system, and these samples showed stronger mutagenicity in Salmonella typhimurium YG1024 with S9 mix than the other water samples. On the other hand, the river water samples from upstream of the sewage plant were weakly or not mutagenic and PBTA-1 and PBTA-2 were not detected. These results confirmed that a major source of PBTA-1 and PBTA-2 in the Yodo River system is effluent from the sewage plants and that discharged mutagens, including PBTA-1 and PBTA-2, are diluted and/or decomposed while moving down the Yodo River system.

Effects of simultaneous treatment with hydroxyapatite and coffee cherry, the residue left after the removal of coffee beans, on spontaneous mammary tumourigenesis and related parameters in SHN mice

We have found that the chronic administration of the diet containing 5% hydroxyapatite (HAP) derived from bovine or swine bone or drinking water containing 0.5% extract of coffee cherry (CC), the residue left after the removal of coffee beans, induced a marked inhibition of spontaneous mammary tumourigenesis in SHN mice, while the effects decreased with age. In the present study, the combined effects of HAP and CC on mammary tumourigenesis and related parameters were examined. The inhibitory effects of HAP or CC alone on the development and/or the growth of mammary tumours were reduced by HAP + CC. Decreased food and water intake and retarded body growth caused by CC were ameliorated by HAP. Enhancement by HAP or CC of the excretion of the urine components was mostly nullified by HAP + CC. Parameters such as normal mammary gland growth and uterine adenomyosis on which neither HAP nor CC had an effect also did not respond to HAP + CC. These findings suggest that the target is important when administering natural products in combination if the agents are to manifest their effects, additive, synergistic, antagonistic or otherwise.

A transmembrane hybrid-type histidine kinase in Arabidopsis functions as an osmosensor

Water deficit and the resulting osmotic stress affect plant growth. To understand how plant cells monitor and respond to osmotic change from water stress, we isolated a cDNA from dehydrated Arabidopsis plants. This cDNA encodes a novel hybrid-type histidine kinase, ATHK1. Restriction fragment length polymorphism mapping showed that the ATHK1 gene is on chromosome 2. The predicted ATHK1 protein has two putative transmembrane regions in the N-terminal half and has structural similarity to the yeast osmosensor synthetic lethal of N-end rule 1 (SLN1). The ATHK1 transcript was more abundant in roots than other tissues under normal growth conditions and accumulated under conditions of high or low osmolarity. Histochemical analysis of beta-glucuronidase activities driven by the ATHK1 promoter further indicates that the ATHK1 gene is transcriptionally upregulated in response to changes in external osmolarity. Overexpression of the ATHK1 cDNA suppressed the lethality of the temperature-sensitive osmosensing-defective yeast mutant sln1-ts. By contrast, ATHK1 cDNAs in which conserved His or Asp residues had been substituted failed to complement the sln1-ts mutant, indicating that ATHK1 functions as a histidine kinase. Introduction of the ATHK1 cDNA into the yeast double mutant sln1Delta sho1Delta, which lacks two osmosensors, suppressed lethality in high-salinity media and activated the high-osmolarity glycerol response 1 (HOG1) mitogen-activated protein kinase (MAPK). These results imply that ATHK1 functions as an osmosensor and transmits the stress signal to a downstream MAPK cascade.

Chain length of cationic alpha-helical peptide sufficient for gene delivery into cells

To define the minimal peptide length needed for gene delivery into mammalian cells, we synthesized several peptides with shortened chain lengths from the amino-termini of the original amphiphilic peptides (4(6), Ac-LARL-LARL-LARL-LRAL-LRAL-LRAL-NH( 2,) and Hel 11-7, KLLK-LLLK-LWKK-LLKL-LK), which have been known to have gene transfer abilities into cells. Each synthetic peptide was studied for its ability to bind and aggregate with plasmid DNA and the structural change of the peptide caused by binding with the DNA to establish a relative in vitro gene transfection efficiency in COS-7 cells. As a result, the deletion of eight amino acid residues of 4(6) had little influence on their ability, whereas that of 12 amino acid residues remarkably reduced the abilities to make aggregates and transfer the DNA into the cell. In the case of the Hel 11-7 series peptides, deletion of amino acid residues caused a considerable reduction in abilities to bind and form aggregates with DNA and to transfer the DNA into cell in due order. In summary, 16 and 17 amino acid residues were sufficient to form aggregates with the DNA and transfer the DNA into the cells in the deletion series of 4(6) and Hel 11-7, respectively. Furthermore, it was indicated that reduction of membrane perturbation activity of the peptide-DNA complex due to deletion of the peptide chain length caused suppression of the transfection efficiency even if the complex was incorporated into the cells. Transfer of the complex to cytosol mediated by membrane perturbation activity of the peptide is an important step for efficient protein expression from its cDNA. The results of this study will make it easy to design and synthesize a functional gene carrier molecule such as a carbohydrate-modified peptide used in targeted gene delivery.

Surgical management of arteriosclerotic coronary artery aneurysm

A 60-year-old man suffered antero-septal myocardial infarction at the age of 56. Coronary angiography demonstrated total occlusion of the left anterior descending artery and a large saccular aneurysm of the right coronary artery. Diffuse coronary ectasia was also shown in the right coronary artery adjacent to the aneurysm. Despite anticoagulant therapy, the aneurysm formed a thrombus and developed coronary artery stenosis distal to the aneurysm. Ligation of the aneurysm and in situ gastroepiploic artery grafting were performed. Sudden heart failure was developed during skin closure. As this condition was considered to be graft hypoperfusion, supplemental saphenous vein grafting was placed. Ligation is a simple, reliable technique to prevent future complications for a large saccular right coronary artery aneurysm, however, gastroepiploic artery might be an inappropriate bypass conduit for the ligated coronary artery with diffuse ectasia.

Familial hypercholesterolemia in Utah kindred with novel 2412-6 Ins G mutations in exon 17 of the LDL receptor gene

Familial hypercholesterolemia (FH) is a monogenic disorder associated with primary hypercholesterolemia. FH is characterized by autosomal co-dominant inheritance with strikingly elevated LDL-cholesterol, the presence of xanthoma and premature atherosclerosis. In the course of investigations of coronary artery disease in Utah, we identified a family whose proband showed elevated plasma levels of LDL cholesterol. To determine the genetic etiology of the lipoprotein abnormalities, we screened DNA samples from the family for mutations in all 18 exons and the exon- intron boundaries of the low-density lipoprotein receptor (LDLR) gene. Novel point mutations were identified in the proband: a one-base insertion of G to a five-G stretch at nucleotides 2412-6 (codons 783-785), causing a frameshift in exon 17 of the LDL receptor gene. The direct sequencing method was used to examine six members of the family recruited for the diagnosis. This method helped to unequivocally diagnose the five individuals as heterozygous for this particular LDL receptor mutation. This method also helped us to diagnose with FH, or to exclude from carrier status, three children between ages 6 and 11.

[Clinical studies of faropenem in the field of obstetrics and gynecology]

The clinical effect of faropenem was evaluated in 165 ambulatory patients with various infections in the field of obstetrics and gynecology at 10 institutions in Yamagata Prefecture. The results obtained are summarized below. 1. The rate of efficacy, as determined from the clinical effect following 3- to 7-day repeated administration at a dose of 600 mg/day, was 97.9% (46/47) for intrauterine infections, 92.0% (23/25) for adnexitis, 93.8% (15/16) for external genital infections, 88.9% (8/9) for mastitis, 94.0% (63/67) for cystitis, and 100% (1/1) for cervicitis. The overall efficacy rate was estimated to be 94.5% (156/165). 2. The rate of clinical efficacy, as classified by isolate, was high, 95.1% for Gram-positive bacteria, 100% for Gram-negative bacteria, and 100% for anaerobes. As for bacteriological response classified by isolate, the eradication rate was high, 91.4% (74/81) for Gram-positive bacteria, 98.4% (62/63) for Gram-negative bacteria, 89.5% (17/19) for anaerobes, and 93.9% (153/163) in all. 3. No adverse reactions or laboratory abnormalities were observed in any patient. The results presented suggest that faropenem is a highly safe and effective antibiotic for the treatment of obstetric or gynecological infections of various kinds in an ambulatory setting.

The relevance of N-linked glycosylation to the binding of a ligand to guanylate cyclase C

The role of carbohydrate moieties at the N-linked glycosylation sites of guanylate cyclase C (GC-C), a receptor protein for guanylin, uroguanylin and heat-stable enterotoxin, in ligand binding and structural stability was examined using site-directed mutagenesis of the putative N-linked glycosylation sites in the extracellular domain (ECD) of porcine GC-C. For this purpose, eight mutant proteins of ECD (N9A, N20A, N56A, N172A, N261A, N284A, N334A and N379A) and six mutant proteins of the complete GC-C (N9A, S11A, N172A, T174A, N379A and T381A) were prepared, in which Ala replaced Asn, Ser and Thr at the N-linked glycosylation consensus sites. All the mutant proteins showed a ligand-binding affinity (K(d)) similar to those of the wild-type proteins, although the deletion of a carbohydrate moiety at each of the N-linked glycosylation sites affected the ligand-binding ability of ECD or GC-C to some degree. However, the mutant proteins of ECD (N379A) and GC-C (N379A and T381A) showed considerably decreased binding ability in the context of maximum capacity (B(max)) to a ligand, despite the fact that the expression levels of these mutant proteins were nearly the same as the wild-type proteins. Moreover, the mutant protein of ECD (N379A) was considerably less stable to a denaturant. These results clearly indicate a crucial role for the carbohydrate moiety at N379, which is located near the transmembrane region, in structural stability, the ability to bind to a ligand and the cyclase catalytic activity of GC-C, and provide a route for the elucidation of the mechanism of the interaction between GC-C and a ligand.

Familial hypercholesterolemia in Utah kindred with novel R103W mutations in exon 4 of the LDL receptor gene

Heterozygous familial hypercholesterolemia (FH) is a serious disorder causing twice normal low-density lipoprotein cholesterol levels early in childhood and very early coronary disease in both men and women. Previously published blood cholesterol criteria greatly under-diagnosed new cases of FH among members of known families with FH and over-diagnosed FH among participants of general population screening. Thus, there is a need for accurate and genetically validated criteria for the early diagnosis of heterozygous FH. In the course of investigations of coronary artery disease in Utah, we identified a family whose proband showed elevated plasma levels of LDL cholesterol. To carry out molecular genetic diagnosis of the disease, we screened DNA samples for mutations in all 18 exons and the exon- intron boundaries of the low-density lipoprotein (LDL) receptor gene. Novel point mutations were identified in the proband: a C-to-T transversion at nucleotide position 369, causing substitution of Tryptophan for Arginine at codon 103 in exon 4 of the LDL receptor gene. The SSCP method was used to examine seven members of the family recruited for the diagnosis. This method helped to unequivocally diagnose only the proband as heterozygous for this particular LDL receptor mutation while excluding the remaining six individuals from carrier status with FH.

EIN2, a bifunctional transducer of ethylene and stress responses in Arabidopsis

Ethylene regulates plant growth, development, and responsiveness to a variety of stresses. Cloning of the Arabidopsis EIN2 gene identifies a central component of the ethylene signaling pathway. The amino-terminal integral membrane domain of EIN2 shows similarity to the disease-related Nramp family of metal-ion transporters. Expression of the EIN2 CEND is sufficient to constitutively activate ethylene responses and restores responsiveness to jasmonic acid and paraquat-induced oxygen radicals to mutant plants. EIN2 is thus recognized as a molecular link between previously distinct hormone response pathways. Plants may use a combinatorial mechanism for assessing various stresses by enlisting a common set of signaling molecules.

Coronary revascularization with arterial conduits collateral to the lower limb

A 62-year-old man with left main coronary artery disease had coronary artery bypass grafting. Angiography disclosed total occlusion of the left common iliac artery. The left internal thoracic artery and the left inferior epigastric artery were well developed as collateral pathways to the left external iliac artery. With concomitant femoro-femoral crossover bypass, these two large arterial conduits were harvested and grafted to the coronary artery.

RESPONSIVE-TO-ANTAGONIST1, a Menkes/Wilson disease-related copper transporter, is required for ethylene signaling in Arabidopsis

Ethylene is an important regulator of plant growth. We identified an Arabidopsis mutant, responsive-to-antagonist1 (ran1), that shows ethylene phenotypes in response to treatment with trans-cyclooctene, a potent receptor antagonist. Genetic epistasis studies revealed an early requirement for RAN1 in the ethylene pathway. RAN1 was cloned and found to encode a protein with similarity to copper-transporting P-type ATPases, including the human Menkes/Wilson proteins and yeast Ccc2p. Expression of RAN1 complemented the defects of a ccc2delta mutant, demonstrating its function as a copper transporter. Transgenic CaMV 35S::RAN1 plants showed constitutive expression of ethylene responses, due to cosuppression of RAN1. These results provide an in planta demonstration that ethylene signaling requires copper and reveal that RAN1 acts by delivering copper to create functional hormone receptors.

High-performance liquid chromatography-fluorescence determination of dinitropyrenes in soil after column chromatographic clean-up and on-line reduction

In order to quantify 1,3-dinitropyrene (DNP), 1,6-DNP and 1,8-DNP in soil, we developed an efficient clean-up procedure and a sensitive determination method using fluorescence detection. DNP isomers were efficiently cleaned by three stages of fractionation, i.e., a silica gel open column chromatography using stepwise elution and two further purification steps by high-performance liquid chromatography (PPLC) using a monomeric-type octadecylsilyl (ODS) column and a polymeric-type ODS column. The recoveries of DNPs during the whole clean-up process were 94% or more. The fraction corresponding to DNPs was injected into an analytical polymeric-type ODS column for HPLC to separate DNP isomers. The effluent from the analytical ODS column was directly introduced to a catalyst column, which was packed with 5 microns alumina coated with platinum and rhodium (Pt-Rh), in order to reduce DNPs to diamino compounds, and then the fluorescence of diaminopyrenes was detected. The immediate detection of diaminopyrene isomers after on-line reduction afforded a sensitive detection of DNP isomers. The detection limits for DNPs were in the range of 0.7 to 4 pg. These developed methods were applied to four soil samples collected at parks in residential areas.

Expression and characterization of the extracellular domain of guanylyl cyclase C from a baculovirus and Sf21 insect cells

Guanylyl cyclase (GC)-C, a single-transmembrane receptor protein for heat-stable enterotoxin, guanylin, and uroguanylin, and its N-terminal extracellular domain were prepared at a high level of expression from a system constructed of Sf21 insect cells and recombinant baculovirus. The recombinant GC-C, containing the complete sequence, retained its binding affinity to heat-stable enterotoxin with a KD value (6.2 x 10(-10) M) and cyclase catalytic activity at a level similar to those of GC-C expressed in mammalian cell lines, such as COS-7. The N-terminal extracellular domain was prepared in a form which contained the hexahistidine tail at its C-terminus and was purified as a homogenous protein by Con A and Ni-chelating affinity chromatography from the culture medium of the insect cells. The purified N-terminal extracellular domain of GC-C exhibited the high (KD = 4 x 10(-10) M) and low (KD = 7 x 10(-8) M) affinity sites in binding to heat-stable enterotoxin. These results clearly indicate that the N-terminal extracellular domain of GC-C possesses the same biochemical characteristics as the complete GC-C protein even in the membrane-free form. Moreover, the extracellular domain is able to form an oligomer in a ligand-dependent manner, suggesting that the N-terminal extracellular domains interact with one another in binding to ligands.

Nitrite reductase from Pseudomonas aeruginosa released by antimicrobial agents and complement induces interleukin-8 production in bronchial epithelial cells

We have recently reported that nitrite reductase, a bifunctional enzyme located in the periplasmic space of Pseudomonas aeruginosa, could induce interleukin-8 (IL-8) generation in a variety of respiratory cells, including bronchial epithelial cells (K. Oishi et al. Infect. Immun. 65:2648-2655, 1997). In this report, we examined the mode of nitrite reductase (PNR) release from a serum-sensitive strain of live P. aeruginosa cells during in vitro treatment with four different antimicrobial agents or human complement. Bacterial killing of P. aeruginosa by antimicrobial agents induced PNR release and mediated IL-8 production in human bronchial epithelial (BET-1A) cells. Among these agents, imipenem demonstrated rapid killing of P. aeruginosa as well as rapid release of PNR and resulted in the highest IL-8 production. Complement-mediated killing of P. aeruginosa was also associated with PNR release and enhanced IL-8 production. The immunoprecipitates of the aliquots of bacterial culture containing imipenem or complement with anti-PNR immunoglobulin G (IgG) induced twofold-higher IL-8 production than did the immunoprecipitates of the aliquots of bacterial culture with a control IgG. These pieces of evidence confirmed that PNR released in the aliquots of bacterial culture was responsible for IL-8 production in the BET-1A cells. Furthermore, the culture supernatants of the BET-1A cells stimulated with aliquots of bacterial culture containing antimicrobial agents or complement similarly mediated neutrophil migration in vitro. These data support the possibility that a potent inducer of IL-8, PNR, could be released from P. aeruginosa after exposure to antimicrobial agents or complement and contributes to neutrophil migration in the airways during bronchopulmonary infections with P. aeruginosa.

Application of Bead-ELISA method to detect Helicobacter pylori VacA

Helicobacter pylori is an etiological agent of gastritis, gastric ulcer and gastric cancer. In order to clarify the significance of vacuolating cytotoxin (VacA) for the pathogenesis of Helicobacter pylori infection, we established and applied the sandwich bead enzyme-linked immunosorbent assay (Bead-ELISA) for quantitative determination of VacA in the culture mediums of H. pylori and other species of Helicobacter. The minimum concentration of VacA in culture medium detected by Bead-ELISA was 25 pg VacA/ml and its sensitivity was found to be quite high compared to vacuolation assay and Western blot analysis, e.g. the minimum concentrations of VacA in culture medium required for detection by vacuolation assay and Western blotting were 11 ng/ml and 38 ng/ml, respectively. All the H. pylori strains used were found to produce VacA in the culture medium by Bead ELISA, even though some strains were negative by Western blot and vacuolation assay. The results obtained by Bead-ELISA was consistent with those by PCR amplification of a 785 bp vacA fragments. A toxin immunologically similar to VacA produced by other strains of Helicobacter such as H. muridarum (ATCC49282), H. mustelae (F10) and H. felis (ATCC49179) could not be detected by Bead-ELISA as well as Western Blot.

Characterization of the YbBa2Cu3O7-y and YBa2Cu3O7-y thin superconducting films prepared by chemical solution deposition on MgO(001) substrate

Thin superconducting films of the YbBa2Cu3O7-y (Yb123) and YBa2Cu3O7-y (Y123), prepared by post-deposition annealing of the metal naphthenates gels spin-coated on MgO(001) substrate, have been characterized by cross-sectional high-resolution electron microscopy and X-ray diffraction. It was found that the c-axis Yb123 films were epitaxially grown on the MgO(001) substrate at the temperature range from 700 degrees C to 775 degrees C in a gas mixture containing Ar and O2 with the oxygen partial pressure of p(O2) = 10(-4) atm. In contrast to the Yb123 films, it was found that Y123 films could be derived at a wider temperature range from 750 degrees C to 950 degrees C. Randomly oriented Y123 films were also grown on the MgO(001) substrate besides the majority of in-plane c-axis oriented growth.

Vacuolating cytotoxin purified from Helicobacter pylori causes mitochondrial damage in human gastric cells

We investigated the effects of vacuolating cytotoxin (VacA) prepared from Helicobacter pylori on the metabolism of gastric epithelial cells, AZ-521. VacA caused the ATP levels to decrease in a time-dependent manner; by approximately 20% in 6 h, 35% in 12 h and 50% in 24 h, at a concentration of 120 nM. This decrease was also dependent on the concentration of VacA. To evaluate the impairment of mitochondria by VacA, mitochondrial membrane potential was estimated by flow cytometric analysis using 3, 3'-dihexyloxacarbocyanine iodide as a substrate. VacA decreased membrane potential with the relative fluorescence intensity of AZ-521 cells in 6 h from 52+/-3 to 24+/-1. Treatment of the cells with bafilomycin A1, a specific inhibitor of vacuolar ATPase proton pump, showed no apparent effect on these changes in the levels of ATP and the mitochondrial membrane potential. Secondly, we estimated the effect of VacA on oxygen consumption. VacA inhibited oxygen consumption in AZ-521 cells: the levels of PO 2 in the medium of control cells decreased by 73% in 3 h and 37% in 6 h, whereas those in VacA-treated cells were 84% in 3 h and 59% in 6 h. Flow cytometric analysis showed the number of cells in the G0/G1 phase was increased by VacA. Taken together, VacA induced an inactivation of energy metabolism followed by mitochondrial damage, leading to impairment of the cell cycle in gastric epithelial cells.

Five familial hypercholesterolemic kindreds in Japan with novel mutations of the LDL receptor gene

In the course of investigations of familial coronary artery disease in Hokkaido, the northern island of Japan, we identified five families in which multiple members showed elevated plasma levels of low-density lipoprotein (LDL) cholesterol. To determine the genetic etiology of their lipoprotein abnormalities, we screened DNA samples from these families for mutations in all 18 exons and the exon-intron boundaries of the LDL receptor (LDLR) gene. Novel point mutations were identified in each family: (1) a C-to-A transversion at nucleotide 285, causing a nonsense mutation at codon 74, in eight members of family A; (2) a G-to-A transition at nucleotide 1136, causing substitution of Tyr for Cys at codon 358, in six members of family B; (3) a C-to-T transition at nucleotide 1822, causing substitution of Ser for Pro at codon 587, in five members of family C; (4) a one-base insertion of G to a five-G stretch at nucleotides 1774-1778 (codons 571-572), causing a frameshift, in six members of family D; and (5) a one-base deletion of T at nucleotide 1963-1964 (codon 634), causing a frameshift, in three members of family E. Through the molecular genetic approach a total of 28 individuals in these families were diagnosed unequivocally as heterozygous for the respective LDLR mutations. This method also helped us to diagnose familial hypercholesterolemia, or to exclude from carrier status, 11 children with borderline high cholesterol levels.

Identification of 1,6- and 1,8-dinitropyrene isomers as major mutagens in organic extracts of soil from Osaka, Japan

The organic extracts of soil collected at parks in residential areas in Osaka and neighboring cities in the Kansai area, Japan, showed mutagenicity in Salmonella typhimurium strain TA98 in the presence or absence of a mammalian metabolic activation system (S9 mix). The soil extracts from Ibaraki and two different sites in Osaka, i.e., Sumiyoshi-ku and Minato-ku, were mutagenic in strain TA100 as well as in strain TA98. Direct-acting mutagenicity of soil extracts from Sumiyoshi-ku and Minato-ku toward strain TA98 were 66 or more times higher than that of the other cities. Both extracts exerted stronger mutagenicity in strains YG1021 and YG1024 than TA98 and TA100, and the potency was especially high in strain YG1024: Sumiyoshi-ku, 153 000 revertants/g of soil; and Minato-ku, 246 000 revertants/g of soil. Two mutagenic compounds (I and II) were isolated from the Soxhlet extract of soil from the park in Sumiyoshi-ku by repetitive separation using normal-phase and reversed-phase column chromatography. By comparing the mass and UV spectra and retention times for HPLC on two individual ODS columns of compounds I and II with those of authentic chemicals, we identified these two compounds as 1,6- and 1,8-dinitropyrene (DNPy) isomers. Amounts of DNPy isomers in soil from Sumiyoshi-ku and Minato-ku were 1.7-2.2 ng/g. Forty-three percent and 40% of the mutagenicity of soil from Sumiyoshi-ku and Minato-ku could be attributed to these DNPy isomers, respectively.