Endoscope disinfection using chlorine dioxide in an automated washer-disinfector

Although 2% glutaraldehyde is often the first-line agent for endoscopic disinfection, its adverse reactions are common among staff and it is less effective against certain mycobacteria and spore-bearing bacteria. Chlorine dioxide is a possible alternative and an automated washer-disinfector fitted with this agent is currently available. This study was conducted to evaluate the effectiveness of chlorine dioxide in endoscopic disinfection after upper gastrointestinal examination. In vitro microbicidal properties of chlorine dioxide solutions were examined at high (600 ppm) and low (30 ppm) concentrations against various microbes including Pseudomonas aeruginosa, Helicobacter pylori, Mycobacterium avium-intracellulare and Bacillus subtilis in the presence or absence of bovine serum albumin (BSA). Immediately following endoscopic procedures and after application to the automated reprocessor incorporating chlorine dioxide at 30 ppm for 5 min, endoscopic contamination with infectious agents, blood, H. pylori ureA gene DNA and HCV-RNA was assessed by cultivation, sensitive test tape, polymerase chain reaction (PCR) and reverse transcriptase-PCR analysis, respectively. Chlorine dioxide at 30 ppm has equivalent microbicidal activity against most microbes and faster antimicrobial effects on M. avium-intracellulare and B. subtilis compared with 2% glutaraldehyde, but contamination with BSA affected the microbicidal properties of chlorine dioxide. Endoscopic contamination with microbes, blood and bacterial DNA was eliminated after application of the automated reprocessor/chlorine dioxide system. Thus, chlorine dioxide is a potential alternative to glutaraldehyde. The use of automated reprocessors with compatibility to chlorine dioxide, coupled with thorough pre-cleaning, can offer effective, faster and less problematic endoscopic disinfection.

[A case of long-term, high-dose transdermal fentanyl application for lung cancer pain]

Transdermal fentanyl patch represents a new administration route for cancer pain relief. We reported here a successful experience with a high-dose of transdermal fentanyl for cancer pain therapy. A 71-year-old woman suffering from metastatic lung cancer to bone had already been treated with radiation at a different hospital. She suffered from severe lumbar pain upon admission to our hospital. During the past 15 months, she has been treated with 30 mg or more of transdermal fentanyl for cancer pain relief. No severe side effects were observed, and she experienced a better quality of life at home using this patch long-term.

Two States of the Triple Helix in the Thermal Transition of the Collagen Model Peptide (Pro-Pro-Gly)10

The collagen model peptide (Pro-Pro-Gly)10 is known to fold into a triple helix in solution. So far, the triple helix has been considered to exist as a single state. However, our previous study of (Pro-Pro-Gly)10 in solution has indicated the presence of two different states of the triple helix, a lower (HL) and a higher temperature state (HH). In the present study, these triple-helical states were investigated in more detail by NMR. Complete stereospecific assignments of the methylene protons of the proline residues were accomplished by the use of NOESY and TOCSY spectra. The temperature dependence of the 1H chemical shifts showed that the HL-to-HH thermal transition can be attributed to a conformational change of the first proline (Pro1) residues of the (Pro-Pro-Gly) triplets. Since TOCSY spectra with a 10 ms mixing-time confirmed a down puckering of these Pro residues in the HL state, but interconverting down and up puckerings in the HH state, the HL-to-HH thermal transition corresponds to conformational changes of the pyrrolidine rings of the Pro1 residues from an uniform down puckering to a more flexible state. The results confirm that thermal unfolding of the triple helix proceeds through the intermediate HH state.

Elastase-induced changes in lung function: relationship to morphometry and effect of drugs

Intratracheal administration of porcine pancreatic elastase (PPE) produced a dose related decline in lung function, as assessed by changes in dynamic lung compliance (C(dyn)) in New Zealand White rabbits. This occurred within 24 h of administration and persisted for 56 days (n=6). These lung function changes were accompanied by histological evidence of emphysema in the lungs and were not mimicked by intratracheal administration of the proteolytic enzyme trypsin. Neither the lung function nor the histological changes induced by elastase could be prevented or reversed by either the glucocorticosteroid, dexamethasone, or all trans retinoic acid (ATRA).Our data suggest that local administration of elastase to the lungs of rabbits may provide a convenient way to assess the effects of drugs on the changes induced by elastase in airways.

Dynamic viscoelastic properties of commercial glass-fibre reinforced resin used for crowns and bridges

In order to investigate the thermal stability, the physical and mechanical, and dynamic viscoelastic properties of glass-fibre reinforced composite materials were measured. The G' of the seven materials examined was within 5;20 +/- 14; 55 and 4;50-14; 35 GPa for dry and wet specimens in air at 37 degrees C, respectively, and decreased with increasing temperature. The G' values of dry specimens decreased by 7;74-15;4% when heated to 60 degrees C. The value of tan delta ranged from 0;0102 to 0;0295 and from 0.0181 to 0.0406 for dry and wet specimens in air at 37 degrees C, respectively. The coefficient of linear thermal expansion between 30 and 60 degrees C ranged from 0;557 to 3; 95 x 10-5/ degrees C. Moreover, the filler content ranged from 56; 36 to 88; 87 wt%. These results showed that the magnitudes of G', tan delta, and the coefficient of linear thermal expansion and water absorption depend on the inorganic filler or glass-fibre content; i.e. the amount of resin matrix. Moreover, for all the materials examined, the G' values were thermostable in the temperature range encountered in the oral cavity.

Clonal evolution and progression of 20-methylcholanthrene-induced squamous cell carcinoma of mouse epidermis as revealed by DNA instability and other malignancy markers

We examined the clonal evolution of skin malignant lesions by repeated topical applications of 20-methylcholanthrene (20-MC) to the skin, which induces hyperplastic epidermis, papillomatous lesion and invasive carcinoma in mice. The lesions were examined histologically and immunohistochemically with anti-single-stranded DNA after acid hydrolysis (DNA-instability test), p53, VEGF, DFF45, PCNA and AgNORs parameters analyses. Multiple clones with increased DNA instability comparable to that of invasive carcinoma were noted in early-stage (2-6 weeks) hyperplastic epidermis, and their number increased in middle (7-11 weeks), and late-stages (12-25 weeks) of hyperplastic epidermis, indicating that they belong to the malignancy category. All papillomatous lesions and invasive carcinomas showed a positive DNA-instability test. Positive immunostaining for various biomarkers and AgNORs parameters appeared in clones with a positive DNA-instability test in early-or middle-stage hyperplastic epidermis, and markedly increased in late-stage hyperplastic epidermis, papillomatous lesions and invasive carcinomas. The percentage of PCNA-positive vascular endothelial cells was significantly higher in VEGF-positive lesions with a positive DNA-instability test and became higher toward the late-stage of progression. Cut-woundings were made to papillomatous and invasive carcinoma lesions, and the regeneration activity of vascular endothelial cells was determined by using flash labeling with tritiated thymidine (3H-TdR). In small papillomatous lesions, vascular endothelial cells showed regenerative response, but the response was weak in large lesions. No such response was noted in invasive carcinomas; rather, cut-wounding induced collapse of blood vessels, which in turn induced massive coagulative necrosis of cancer cells. These responses can be interpreted to reflect exhausted vascular growth activity due to excessive stimulation by VEGF-overexpression, which was persistently seen from hyperplastic epidermis to invasive carcinoma.

Immunohistochemical detection of early-stage carcinogenesis of oral leukoplakia by increased DNA-instability and various malignancy markers

The degree of DNA instability as determined by immunohistochemical staining with anti-single-stranded DNA antibody after acid hydrolysis (the DNA instability test) was used as a marker of malignancy. The test was applied to tissues of oral leukoplakia assessed histopathologically as hyperplasia (38 cases), mild (12 cases), moderate (11 cases) and severe (8 cases) dysplasia, and invasive squamous cell carcinoma (SCC, 20 cases). Tissues were subjected to immunohistochemical staining for proliferating cell nuclear antigen (PCNA), p53, DNA-fragmentation factor 45 (DFF45), analysis of various AgNORs parameters, and triple immunostaining for vascular endothelial growth factor (VEGF), CD34, and PCNA. The DNA instability test was positive in 20 (100%) SCC cases, 8 (100%) severe dysplasia cases, 8 (72.7%) moderate dysplasia cases, 6 (50.0%) mild dysplasia cases, and 9 (23.7%) hyperplasia cases, indicating malignancy. The proportion of lesions positive for PCNA, p53, DFF45, and values of AgNORs parameters steadily increased from hyperplasia to mild, moderate and severe dysplasia, and SCC, especially in those showing positive DNA instability test, indicative of malignancy. Based on these results, 44.9% of leukoplakia were malignant tissues, namely carcinoma in situ. The proportion of PCNA-positive vascular endothelial cells in the vicinity of VEGF-positive epithelial lesion was significantly higher than that of negative DNA instability lesions, as revealed by immunohistochemical triple staining for VEGF, CD34, and PCNA. Our results suggest that increased DNA instability, enhanced proliferative activity, p53 mutation, and induction of DFF45 and VEGF may allow cancer cell proliferation, enhance their survival by escaping apoptosis, and provide abundant nutrients during early-stage carcinogenesis of oral leukoplakia.

Signal detection of endothelin receptor subtypes in human cirrhotic liver by a new in situ hybridization method

Endothelin (ET) has been implicated in the regulation of hepatic microcirculation and development of portal hypertension, but the role of ET in cirrhosis of the liver has not yet been elucidated. We present here the application of peptide nucleic acid (PNA) probes in a fast and sensitive in situ hybridization (ISH) method for localizing the mRNA of endothelin receptor subtypes in formalin-fixed, paraffin-embedded sections of normal and cirrhotic human liver. The results of ISH using synthetic FITC-labeled PNA probes combined with the catalyzed signal amplification (CSA) system were compared with those using the standard detection system. It was indicated that the CSA-ISH protocol is more sensitive for the detection of mRNA target than the standard ISH protocol. Our results with CSA-ISH showed that the expression of mRNA for the endothelin B receptor was significantly upregulated in hepatic sinusoidal lining cells in cirrhotic human liver tissues compared to control normal liver tissue. Therefore, the CSA detection system may facilitate and enhance the use of in situ hybridization protocols, and CSA-ISH will be used as an important diagnostic technique in the future.

The development of lithium ion secondary batteries

Lithium ion secondary batteries (LIBs) were successfully developed as battery systems with high volumetric and gravimetric energy densities, which were inherited from lithium secondary batteries (LSBs) with metallic lithium anodes. LSBs have several drawbacks, however, including poor cyclability and quick-charge rejection. The cell reaction in LIB is merely a topochemical one, namely the migration of lithium ions between positive and negative electroces. No chemical changes were observed in the two electrodes or in the electrolytes. This results in little chemical transformation of the active electrode materials and electrolytes, and thus, LIBs can overcome the weaknesses of LSBs; for example, LIBs show excellent cyclability and quick-charge acceptance. Many difficulties, however, were encountered during the course of development, including capacity fade during cycling and safety issues. This article is the story of the development of LIBs and it describes how the difficulties were surmounted.

Computational 3-D modeling and site-directed mutation of an antibody that binds Neu2en5Ac, a transition state analogue of a sialic acid

An antibody against a transition state analog (TSA) may share some common features with an enzyme that produces such a transition state. SIC172 antibody binds specifically to Neu2en5Ac, a TSA of Neu5Ac in the sialidase reaction, but has no catalytic activity. To understand how the antibody recognizes Neu2en5Ac and to find out if it is possible to convert it to a catalytic antibody, we made and sequenced the SIC172 ScFv, and constructed a 3-D model of it. The VH-CDR3 contains a unique sequence with Cys at H95. The 3-D model showed that Cys-H95 is exposed inside the antigen-binding cavity. After affinity docking, 4 types emerged. In type I, the carboxyl group of Neu2en5Ac is located near the Cys-H95 and neighboring positively charged residues. The change of Cys-H95 to Asp by site-directed mutation decreased the binding activity, while a change to Arg did not. These and other mutation experiments, and further modeling of mutant Fv, support the 3-D model and docking type I. A comparison with sialidase indicates that SIC172 antibody appears to have some groups of residues that are conserved at the active site of the enzyme. The possibility of Neu2en5Ac-binding antibody being converted to a catalytic antibody is discussed.

[Delayed paraparesis after osteoporotic vertebral fracture--with special reference between mechanism of symptoms, fracture level, age and operative methods]

We examined the operated 53 cases with delayed paraparesis after osteoporotic vertebral fracture. The causes of the symptoms were complicated and the analysis indicated that the anterior approach should be the first choice, however the posterior approach could be indicated for the following cases ; the main causes are posterior elements, multiple involvement, at middle and lower lumbar level, with severe osteoporosis, with systemic complication, over 80 years old. For high aged and osteoporotic patients, careful analysis of factors causing symptoms and less invasive operation as possible are needed.

Regulation of aromatase by nuclear receptors

We investigated the effects of a nuclear receptor system constituted by retinoid X receptor (RXR) and its heterodimer partner on the aromatase activity in a cultured MCF-7 human breast cancer cell line and also in human ovarian granulosa cells, using each selective ligand for retinoic acid receptor, RAR (TTNPB), retinoid X receptor, RXR (LG100268), PPARgamma (troglitazone), and vitamin D3 receptor (cholecalciferol). In MCF-7 cells, the combined treatment with TTNPB and LG100268 caused a dramatic stimulation of the aromatase activity. The combined treatment with other ligand and LG100268 had little or no effect on the aromatase activity. The increase in the aromatase activity by TTNPB plus LG100268 was accompanied by an increase in the P450arom mRNA levels, which was also found to be related to the specific usage of promoter 1a of the CYP19 gene. These results suggest that a nuclear receptor system constituted by a RAR:RXR heterodimer is involved in the regulation of aromatase activity in MCF-7 breast cancer cells. In cultured human ovarian granulosa cells obtained from patients who underwent in vitro fertilization, troglitazone or LG100268 alone decreased the aromatase activity, while the combined treatment caused an even greater reduction in this activity. Little effect of other specific ligands for RXR heterodimer partners may support the notion that the effects of troglitazone and/or LG100268 in human granulosa cells may be mediated through the specific activation of PPARgamma:RXR heterodimer system. Since similar manners of effects of several PPARgamma ligands and/or LG100268 on the aromatase activity were observed in a newly established human ovarian granulosa cancer cell line, KGN, we performed the detailed analysis of the mechanisms of these effects using this cell line. As a result, the inhibitory effect of aromatase activity by troglitazone plus LG100268 was accompanied by the decrease of P450arom mRNA level. Furthermore, the loss of P450arom expression was considered to be due to both the decreased transcription and rapid degradation of its RNA based on the studies of nuclear run-on assay and RNA stability assay. In conclusion, RAR:RXR and PPARgamma:RXR heterodimer nuclear receptor systems may be other important modulators of estrogen production in human breast cancer cells and ovarian granulosa cells, respectively.

Tributyltin or triphenyltin inhibits aromatase activity in the human granulosa-like tumor cell line KGN

The superimposition of male sex organs (penis and vas deferens) in a female gastropod, called imposex, is widely attributed to the exposure to tributyltin (TBT) compounds, used world-wide in antifouling paints for ships. It has been hypothesized that the TBT-induced imposex is mediated by an increasing androgen level relative to the estrogen level, namely a decreased conversion of androgens to estrogens (i.e., aromatization). In the present study, we tested this hypothesis by examining the effects of TBT or triphenyltin (TPT) on the aromatase activity in a cultured human granulosa-like tumor cell line, KGN, which was recently established by our group. Treatment with more than 1000 ng/ml TBT compounds was very toxic to the cells and caused immediate cell death within 24 h, while 200 ng/ml was found to cause apoptosis of the cells. Treatment of the KGN cells for more than 48 h with 20 ng/ml TBT or TPT, which is a concentration level reported to cause imposex in marine species, did not affect cell proliferation but significantly suppressed the aromatase activity determined by a [(3)H]H(2)O release assay. Treatment with 20 ng/ml TBT compounds for 7 days also resulted in a reduction of the E2 production from Delta 4-androstenedione stimulated by db-cAMP. The changes in the aromatase activity by TBT compounds were associated with comparable changes in P450arom mRNA assessed by RT-PCR. The luciferase activity of the P450arom promoter II (1 kb) decreased after the addition of 20 ng/ml TBT compounds in transfected KGN cells either in a basic state or in states stimulated by db-cAMP. The Ad4BP-dependent increase in the luciferase activity of P450arom promoter II was also downregulated by such treatments. These results indicate that TBT compounds inhibited the aromatase activity and also decreased the P450arom mRNA level at the transcriptional level in KGN cells. The direct inhibitory effect of TBT compounds on the aromatase activity may therefore partly explain the induction of imposex by these compounds in female species.