Search PubMed⌕ Search

Biomedical subjects

S Kawano

Publications and source records attributed to S Kawano.

At least 73 records · Page 4Linked to original sources

Voltage-dependent effects of Ca(2+)/calmodulin on Cl(-) channel in cardiac sarcoplasmic reticulum.

A new kind of chloride channels in the cardiac sarcoplasmic reticulum, 116 pS Cl(-) channel (500 mM Cl(-) in the cis and 50 mM Cl(-) in the trans chamber solutions), which is activated by protein-kinase-A-dependent phosphorylation, has been determined to conduct adenine nucleotide as a transporter between cytosol and SR lumen. We investigated the voltage-dependent gating of this Cl(-) channel by recording single-channel activities using the planar lipid bilayer-vesicle fusion technique. The channel activities did not change at different membrane potentials (-100 mV to +50 mV) or different Ca(2+) concentrations (1 nM to 1 mM) in cis solution. In the presence of calmodulin (CaM) (0.1 microM /microg SR vesicles), however, Ca(2+) added to the cis solution at 0 mV inhibited channel openings in a Ca(2+) -concentration-dependent manner. These effects were prevented by the addition of CaM inhibitors. The blocking effects of CaM differed depending on the membrane potentials at negative potentials below -20 mV. With CaM and 3 microM Ca(2+), the values of opening probability were 0 at -80 mV, 0.2 at -40 mV, 0.3 at -20 mV, 0.71 at 0 mV and 0.92 at +20 mV. These results may indicate the membrane potential affects the action of Ca(2+) /CaM complex

Animals↗

Changes in calcium, PTH and 1,25(OH)2 vitamin D3 during tail-suspension in ovariectomized rats: effects of estrogen administration.

It is well known that estrogen deficiency results in osteoporosis in human and experimental animals. However, how its deficiency affects the development of disuse atrophy is not well understood. We thus investigated how estrogen deficiency caused by ovariectomy and estrogen supplements affect serum levels of calcium, parathyroid hormone (PTH), and 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) in tail-suspended rats. Five-week-old female Wistar rats were ovariectomized and divided into two groups. One group received an intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received the vehicle alone (OVX group). After the third injection, the rats were subjected to tail-suspension in metabolic cages for 1, 3, 5 or 7 days. In the OVX group, urinary excretion of deoxypyridinoline (D-Pyr) tended to increase on day 1 after tail-suspension. In the OVX-E2 group, basal excretion was lower than that in the OVX group, and no increase was observed after the suspension. Serum concentrations of ionized calcium significantly increased on day 1 after the suspension in both groups. However, in the OVX-E2 group, the level tended to be higher than those in the OVX group from day 0 to day 3. Serum PTH tended to decrease on day 1 after suspension in the OVX group. In the OVX-E2 group, it did not change during the suspension, but the levels were higher than those in the OVX group during the experiment. Serum 1,25(OH)2D3 transiently and significantly increased on day 1 after suspension in both groups. However, in the OVX group, the level was significantly higher than that in the OVX-E2 group. These data indicate that estrogen treatment of ovariectomized rats modifies the changes in calcium metabolism induced by tail-suspension.

Amino Acids↗

Effect of estrogen and tail-suspension on expression of osteocalcin mRNA in femur of ovariectomized rats.

We investigated the effect of estrogen (E2) and tail-suspension on expression of osteocalcin (OC) mRNA in the femur of ovariectomized rats. Five-week-old female Wistar rats were ovariectomized and divided into two groups: one group received estradiol dipropionate (OVX-E2), and the other received the vehicle (OVX). Each group was further divided into two subgroups, tail-suspended (S) and non-suspended (N), giving a total of four groups: OVX-E2-S, OVX-E2-N, OVX-S and OVX-N. After a 7-day suspension, femurs were excised, and OC mRNA levels were determined by Northern blot analysis. A significant decrease of OC mRNA in OVX-E2-N was observed when compared with that of OVX-N, indicating that E2 decreases the OC expression. Interestingly, tail-suspension further decreased the mRNA levels in both OVX-S and OVX-E2-S when compared with the levels of OVX-N and OVX-E2-N, respectively. Since glucocorticoids have been shown to decrease OC expression, we also measured the urinary excretion of corticosterone during the suspension period that reflects the serum levels of corticosterone, and found that it was increased by E2 and further increased by tail-suspension. These results indicate that estrogen and glucocorticoids exert additive effects in inhibiting OC expression in the rat femur.

Animals↗

Myeloid transcription factor C/EBPepsilon is involved in the positive regulation of lactoferrin gene expression in neutrophils.

Targeted mutation of the myeloid transcription factor C/EBPepsilon in mice results in gram-negative septic death at 3 to 5 months of age. This study defines the underlying molecular defects in their terminal granulocytic differentiation. The mRNA for the precursor protein of the cathelin-related antimicrobial peptides was almost completely absent in the bone marrow cells of C/EBPepsilon-/- mice. This finding may help explain their susceptibility to gram-negative sepsis, because both are bacteriocidal peptides with potent activity against gram-negative bacteria. Superoxide production was found to be reduced in both granulocytes and monocytes of C/EBPepsilon-/- mice. While gp91 phox protein levels were normal, p47phox protein levels were considerably reduced in C/EBPepsilon -/- granulocytes/monocytes, possibly limiting the assembly of the NADPH oxidase. In addition, expression of mRNA of the secondary and tertiary granule proteins, lactoferrin and gelatinase, were not detected, and levels of neutrophil collagenase mRNA were reduced in bone marrow cells of the knock-out mice. The murine lactoferrin promoter has a putative C/EBP site close to the transcription start site. C/EBPepsilon bound to this site in electromobility shift assay studies and mutation of this site abrogated binding to it. A mutation in the C/EBP site reduced the activity of the promoter by 35%. Furthermore, overexpression of C/EBPepsilon in U937 cells increased the activity of the wild-type lactoferrin promoter by 3-fold. In summary, our data implicate C/EBPepsilon as a critical factor of host antimicrobial defense and suggests that it has a direct role as a positive regulator of expression of lactoferrin in vivo.

Animals↗

Alteration of interleukin 4 production results in the inhibition of T helper type 2 cell-dominated inflammatory bowel disease in T cell receptor alpha chain-deficient mice.

T cell receptor alpha chain-deficient (TCR-alpha(-/-)) mice are known to spontaneously develop inflammatory bowel disease (IBD). The colitis that develops in these mice is associated with increased numbers of T helper cell (Th)2-type CD4(+)TCR-betabeta (CD4(+)betabeta) T cells producing predominantly interleukin (IL)-4. To investigate the role of these Th2-type CD4(+)betabeta T cells, we treated TCR-alpha(-/-) mice with anti-IL-4 monoclonal antibody (mAb). Approximately 60% of TCR-alpha(-/-) mice, including those treated with mock Ab and those left untreated, spontaneously developed IBD. However, anti-IL-4 mAb-treated mice exhibited no clinical or histological signs of IBD, and their levels of mucosal and systemic Ab responses were lower than those of mock Ab-treated mice. Although TCR-alpha(-/-) mice treated with either specific or mock Ab developed CD4(+)betabeta T cells, only those treated with anti-IL-4 mAb showed a decrease in Th2-type cytokine production at the level of mRNA and protein and an increase in interferon gamma-specific expression. These findings suggest that IL-4-producing Th2-type CD4(+)betabeta T cells play a major immunopathological role in the induction of IBD in TCR-alpha(-/-) mice, a role that anti-IL-4 mAb inhibits by causing Th2-type CD4(+)betabeta T cells to shift to the Th1 type.

Animals↗

Loss of p73 gene expression in leukemias/lymphomas due to hypermethylation.

The p73 gene, a member of the p53 family, is a new candidate tumor suppressor gene. To investigate the possibility of genetic alteration of p73 in leukemia and lymphoma, we examined 55 cell lines and 39 patient samples together with 17 nonhematopoietic cancer cell lines. Gene expression of p73 was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in cell lines (5 of 7 pre B/B-acute lymphoblastic leukemia [ALL], 13 of 21 T-ALL/lymphoblastic lymphomas [LBL], 9 of 10 B-non-Hodgkin's lymphomas [B-NHL], 8 of 9 acute myelogenous leukemias [AML], 2 of 2 T-NHL, 3 of 3 multiple myeloma), and in patient samples (16 of 23 pre B-ALL, 5 of 8 T-ALL/LBL, 5 of 8 B-NHL). PCR-single-strand conformation polymorphism (SSCP) of cDNAs showed no mutation in 43 p73-expressing cell lines within the regions that corresponded to the 5 mutational hotspots of the p53 gene. Neither homologous deletion nor rearrangement of the p73 gene were found by Southern blot analysis in any of the cell lines that lack expression of p73. In contrast to prior published data, analysis of a polymorphic site showed that the p73 gene was expressed biallelically in cell lines and normal peripheral blood. Notably, the p73-negative cell lines were hypermethylated at a CpG island in the 5' untranslated region of the p73 mRNA, and treatment of these cell lines with 5-azacytidine (5-AC), a demethylation reagent, induced p73 expression. Taken together, we found that a sizable proportion (32%) of ALL/B-NHL cell lines and primary tumors had negligible or limited expression of the p73 gene associated with hypermethylation of the gene. These findings suggest that silencing of the p73 gene by hypermethylation may contribute to development and/or progression of lymphoid neoplasms.

DNA Methylation↗

Molecular cloning of transferrin receptor 2. A new member of the transferrin receptor-like family.

Transferrin receptor (TfR) plays a major role in cellular iron uptake through binding and internalizing a carrier protein transferrin (Tf). We have cloned, sequenced, and mapped a human gene homologous to TfR, termed TfR2. Two transcripts were expressed from this gene: alpha (approximately 2.9 kilobase pairs), and beta (approximately 2.5 kilobase pairs). The predicted amino acid sequence revealed that the TfR2-alpha protein was a type II membrane protein and shared a 45% identity and 66% similarity in its extracellular domain with TfR. The TfR2-beta protein lacked the amino-terminal portion of the TfR2-alpha protein including the putative transmembrane domain. Northern blot analysis showed that the alpha transcript was predominantly expressed in the liver. In addition, high expression occurred in K562, an erythromegakaryocytic cell line. To analyze the function of TfR2, Chinese hamster ovary TfR-deficient cells (CHO-TRVb cells) were stably transfected with FLAG-tagged TfR2-alpha. These cells showed an increase in biotinylated Tf binding to the cell surface, which was competed by nonlabeled Tf, but not by lactoferrin. Also, these cells had a marked increase in Tf-bound (55)Fe uptake. Taken together, TfR2-alpha may be a second transferrin receptor that can mediate cellular iron transport.

Amino Acid Sequence↗

Factor XII Tenri, a novel cross-reacting material negative factor XII deficiency, occurs through a proteasome-mediated degradation.

A homozygous cross-reacting material negative factor XII-deficient patient with 3% antigen and activity levels of factor XII was screened for the identification of a mutation at the genomic level. Low-ionic strength single-stranded conformation polymorphism (SSCP) analysis and sequence analysis showed that the proband's gene for factor XII had an A-->G substitution at nucleotide position 7832 in exon 3, resulting in a Tyr34 to Cys substitution in the NH2-terminal type II domain of factor XII. We designated this mutation as factor XII Tenri. Mutagenic polymerase chain reaction (PCR), followed by KpnI digestion, showed a homozygous mutation in the proband's gene and heterozygous mutations in his parents and sister. Immunoprecipitation and Western blot analyses of plasma samples from the factor XII Tenri family indicated that the proband had a trace amount of variant factor XII with an apparent molecular mass of 115 kD, which was converted to the normal 80-kD form after reduction, suggesting that factor XII Tenri was secreted as a disulfide-linked heterodimer with a approximately 35-kD protein, which we identified as alpha1-microglobulin by immunoblotting. Pulse-chase experiments using baby hamster kidney (BHK) cells showed that Tenri-type factor XII was extensively degraded intracellularly, but the addition of cystine resulted in increased secretion of the mutant. Using membrane-permeable inhibitors, we observed that the degradation occurred in the pre-Golgi, nonlysosomal compartment and a proteasome appeared to play a major role in this process. On the basis of these in vitro results, we speculate that the majority of the factor XII Tenri is degraded intracellularly through a quality control mechanism in the endoplasmic reticulum (ER), and a small amount of factor XII Tenri that formed a disulfide-linked heterodimer with alpha1-microglobulin is secreted into the blood stream.

Adult↗

A new scorpion toxin (BmK-PL) stimulates Ca2+-release channel activity of the skeletal-muscle ryanodine receptor by an indirect mechanism.

A peptide toxin isolated from the Chinese scorpion Buthus martensi Karsch (BmK-PL) stimulated Ca2+-release channel activity in both triad membranes and reconstituted ryanodine receptors partially purified from rabbit skeletal muscle. In [3H]ryanodine binding experiments, the toxin increased the affinity of ryanodine for the receptor, from a Kd of 24.3 nM to 2.9 nM, which is an enhancement similar to that seen with known receptor activators, such as ATP and high concentrations of KCl. In contrast, toxin enhancement was not observed with purified receptors, although intrinsic binding activity and stimulation by the conventional receptor activators were retained. In single channel recordings of Ca2+-release activity, the toxin increased the open channel probability (Po) from 0.019 to 0.043 (226% of control) in triad preparations. Further toxin enhancement of Po from 0.07 to 0.37 (529% of control) was observed using partially-purified receptors in the presence of ATP. When purified receptors were assayed in the presence of ATP, however, they showed a high value of Po (0.33) and no further increase was observed following application of the toxin. Results derived from two different experimental methods consistently suggest that a molecule(s) required for toxin-induced enhancement is absent from the purified receptor preparation. Western blot analysis of receptors prepared using three different protocols showed that triadin was missing from the purified receptor preparation. The scorpion toxin minimally enhanced Ca2+-release channel activity of cardiac preparations. From these results, we conclude that the toxin preferentially increases the activity of skeletal-muscle ryanodine receptors by an indirect mechanism, possibly binding to associated protein molecule(s). Triadin is a strong candidate for such a molecule.

Amino Acid Sequence↗

Anion permeability and conduction of adenine nucleotides through a chloride channel in cardiac sarcoplasmic reticulum.

Cardiac sarcoplasmic reticulum (SR) membrane contains several chloride (Cl-) channels. We have characterized a 116-pS Cl- channel (500 mM cis, 50 mM trans Cl-) in cardiac SR that is activated by protein kinase A-dependent phosphorylation. To understand its function further, we examined the permeation of various anions and adenine nucleotides using the planar lipid bilayer-vesicle fusion technique. This Cl- channel showed a high selectivity to anions and its permeability sequence was Br- > Cl- > I- > NO3- > F-. When all anions were replaced with ATP in the cis solution, channel activity persisted. The conductance was 78 pS with 200 mM ATP and 68 pS with 100 mM ATP. The reversal potentials were +63 mV and +41 mV in 200 mM ATP and in 100 mM ATP, respectively. With 100 mM ADP or AMP in the cis solution, channel activities were also observed. The conductances were 87 pS with 100 mM ADP and 115 pS with 100 mM AMP. The apparent adenine selectivity of this channel was ATP > ADP > AMP, assuming that they exist as divalent anions. These results suggest that the SR Cl- channel in cardiac cells may serve as a transporter for the movement of adenine nucleotides between cytosol and SR lumen.

Adenine Nucleotides↗

A pair of invertedly repeated genes in Chlamydomonas reinhardtii encodes a zygote-specific protein whose expression is UV-sensitive.

Uniparental inheritance of the chloroplast genome has been observed in a wide variety of green plants. In Chlamydomonas this phenomenon, which can be selectively inhibited by UV irradiation of mt(+) gametes, has been shown cytologically to be due to the preferential degradation of mt(-)-derived chloroplast nucleoids in young zygotes. The zygote-specific pair of zys1 genes, zys1A and zys1B, is expressed earliest among five genes isolated from a "10-min" zygote library. We report here that the ZYS1 protein, which is encoded by the invertedly duplicated zys1 gene, accumulates in zygotes and is localized in nuclei. In addition, when mt(+) gametes (but not mt(-) gametes) are UV-irradiated before mating, only very limited accumulation of ZYS1 protein can be detected in the resulting zygotes.

Algal Proteins↗

Distribution of synaptosomal-associated protein 25 in nerve growth cones and reduction of neurite outgrowth by botulinum neurotoxin A without altering growth cone morphology in dorsal root ganglion neurons and PC-12 cells.

Synaptosomal-associated protein 25 has been regarded as one of the target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptors essential for exocytosis of vesicles in synapses. We have previously reported that cleavage of syntaxin, which is another target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptor, with botulinum neurotoxin C1 resulted in inhibition of neurite extension and morphological changes including growth cone collapse and large vacuole formation. As an attempt to explore the mechanism of growth cone extension, we examined the ultrastructural localization of synaptosomal-associated protein 25 in growth cones with or without treatment of botulinum neurotoxin A, which cleaves synaptosomal-associated protein 25. In dorsal root ganglion neurons, light microscopy demonstrated synaptosomal-associated protein 25 immunoreactivity throughout the neurons, including the cell bodies, neurites and growth cones. Using electron microscopy, gold signals immunoreactive for synaptosomal-associated protein 25 were identified diffusely in the cytoplasm of the growth cones. In contrast, in PC-12 cells, a large number of gold signals were localized on the plasma membranes. High levels of signal were also found in the cytoplasm in the central region of the growth cones. We also confirmed that botulinum neurotoxin A treatment reduced neurite extension by about 50%. However, both in dorsal root ganglion neurons and in PC-12 cells we found no differences in the ultrastructure nor in the localization of synaptosomal-associated protein 25 between growth cones with and without toxin treatment. These results indicate that cleavage of synaptosomal-associated protein 25 inhibits growth cone extension in a manner different than that of syntaxin cleavage. The results of this study suggest the possibility that synaptosomal-associated protein 25 is involved in growth cone extension through a process independent of vesicle fusion.

Animals↗

Calmodulin mediates calcium-dependent inactivation of the cerebellar type 1 inositol 1,4,5-trisphosphate receptor.

The dependency of purified mouse cerebellar type 1 inositol 1,4,5-trisphosphate receptor (IP3R1)/Ca2+ channel function on cytoplasmic Ca2+ was examined. In contrast to the channels in crude systems, the purified IP3R1 reconstituted into planar lipid bilayers did not show the bell-shaped dependence on Ca2+. It was activated with increasing Ca2+ sublinearly without inhibition even up to 200 microM. The addition of calmodulin to the cytoplasmic side inhibited the channel at high Ca2+ concentrations. Calmodulin antagonists reversed the Ca2+-dependent inactivation of the native channels in cerebellar microsomes. These results indicate that the bell-shaped dependence on cytoplasmic Ca2+ is not an intrinsic property of the IP3R1, and the Ca2+-dependent inactivation is directly mediated by calmodulin.

Animals↗

Structural analyses of new tri- and tetrasaccharides produced from disaccharides by transglycosylation of purified Trichoderma viride beta-glucosidase.

A new beta-glucosidase was partially purified from Trichoderma viride cellulase. This beta-glucosidase catalyzed a transglycosylation reaction of cellobiose to give beta-D-Glc-(1-->6)-beta-D-Glc-(1-->4)-D-Glc (1, yield: 18.8%) and beta-D-Glc-(1-->6)-beta-D-Glc-(1-->6)-beta-D-Glc-(1-->4)-D-Glc (2, 3.7%), regioselectively. Furthermore, the enzyme regioselectively converted laminaribiose and gentiobiose into beta-D-Glc-(1-->6)-beta-D-Glc-(1-->3)-D-Glc (3, 15.3%) and beta-D-Glc-(1-->6)-beta-D-Glc-(1-->6)-D-Glc (4, 20.2%), respectively. The structures (1-4) of the products were determined by 1H and 13C NMR spectroscopies. This high regio- and stereoselectively of the beta-glucosidase could be applied for oligosaccharide synthesis.

Carbohydrate Sequence↗

Technical advance: single pollen typing combined with laser-mediated manipulation.

We combined single pollen typing with laser-mediated manipulation. After drilling a hole in the wall of a pollen grain from a dioecious plant (Silene latifolia) with a UV-laser microbeam, the single pollen grain was recovered directly in the cap of a PCR tube, using a non-contact method called laser pressure catapulting. The entire genome of the single pollen grain was then amplified with improved primer-extension-preamplification PCR (I-PEP PCR). Nested PCR with sequence tagged site (STS)-specific primers was used to analyze several loci in the haploid genome. The single copy gene MROS1 was detected in most of the single pollen grains analyzed. Bgl10, which is localized on the Y chromosome, was detected in approximately half of the pollen grains. MROS3 is reported to be localized on the X chromosome. Using inverse PCR, we isolated two genomic clones of MROS3: MROS3A and MROS3B. The single pollen analysis using nested PCR showed that MROS3A and MROS3B are derived from different loci that are not located on the X chromosome. Single pollen typing not only reveals sex chromosome-linkage within the haploid genome, but can also discriminate between alleles and different loci. This method should also be useful for measuring recombination frequencies without genetic crossover analysis.

Genome, Plant↗

Peripheral vascular resistances during total left heart bypass with an oscillated blood flow.

For development aimed at a totally implantable type ventricular assist device (VAD), the vibrating flow pump (VFP) has been developed at Tohoku University. A transcutaneous energy transmission system (TETS) using amorphous fibers was developed to power the totally implantable VAD system. The VFP works at a high frequency compared to that of a natural heart of a biological system. It is a frequency of 10-50 Hz. In this research, animal experiments with left heart bypass were carried out with healthy adult goats. For comparison between nonpulsatile flow and oscillated flow, a rotary pump (RP) and the VFP were used in the experiments. For the achievement of total left heart bypass, left ventricular approaches were carried out, and blood was pumped from the left ventricle to the descending aorta. Adequate support of the left heart was provided by both pumps. In terms of the results, the vascular resistances tended to decrease during the use of both pumps during 100% bypass driving. When we compared these pumps at the same flow rate, the resistances during RP driving were significantly smaller than those during VFP driving. These results may suggest that the influences of the VFP upon the peripheral vessels may be relatively small compared to those of the RP. This may be an important result when a stable hemodynamic condition is required during artificial circulation. The VFP was considered as a candidate for a totally implantable VAD as a result.

Animals↗

Involvement of cyclooxygenase-2 in proliferation and morphogenesis induced by transforming growth factor alpha in gastric epithelial cells.

Transforming growth factor alpha is one of the most potent growth factors for gastrointestinal epithelium. In this study, we examined the roles of cyclooxygenase-2 on proliferation and morphogenesis of RGM1 rat gastric epithelial cells after stimulation with transforming growth factor alpha in vitro, RGM1 cells increased expression of cyclooxygenase-2 messenger RNA 20-60 min after stimulation with transforming growth factor alpha. Transforming growth factor alpha stimulated [3H]thymidine incorporation and tubulogenesis of RGM1 cells in collagen matrix, both of which were significantly suppressed by treatment with a cyclooxygenase-2 specific inhibitor, NS-398 or cyclooxygenase-2 antisense oligonucleotide. Both of the treatment lowered prostanoid production by enzyme immunoassay. The transforming growth factor alpha-induced expression of cyclooxygenase-2 is followed by cell proliferation and development of tubular morphology of RGM1 gastric epithelial cells. Treatment with cyclooxygenase-2 inhibitor and cyclooxygenase-2 antisense oligonucleotide suppressed these responses induced by transforming growth factor alpha suggesting the involvement of cyclooxygenase-2 in proliferation and morphogenesis in gastric mucosal epithelium.

6-Ketoprostaglandin F1 alpha↗

Endoscope disinfection using acidic electrolytic water.

BACKGROUND AND STUDY AIMS: The aim of the present study was to evaluate a new endoscope disinfector (WM-1) that uses acidic electrolytic water (AEW). MATERIALS AND METHODS: AEW was produced by electrolysis of a 0.05% NaCl-water mixture, with a redox potential greater than 1000 mV and a pH lower than 2.7. In the first study, an endoscope artificially contaminated with 15 species of bacteria and four strains of viruses was treated using the WM-1. In the second study, endoscopic contamination after clinical use was examined by culture for Helicobacter pylori and other bacteria, and by polymerase chain reaction for the H. pylori urease gene and hepatitis C virus. The extent of contamination was then examined after exposing the WM-1 to AEW. The safety of AEW was examined using both in vivo and in vitro studies. RESULTS: All of the bacteria and viruses were destroyed or inactivated after the instrument had been exposed to AEW. Clinical contamination was detected from the instrument in 19 of 30 endoscopic procedures, whereas no bacteria or viruses were detected after five minutes' exposure to AEW. AEW was found to be nonirritant, nontoxic to cells, and nonmutagenic. CONCLUSION: The WM-1 successfully and safely disinfected the endoscopes. With running costs of yen 24 per day ($0.21 per day), the WM-1 provides an effective and inexpensive alternative to conventional disinfection equipment.

Acids↗