Showing papers by "Hiroshi Maeda published in 1999"
TL;DR: A diet rich in these radical scavengers would reduce the cancer-promoting action of ROO(*).
Abstract: We recently reported that alkylperoxyl radical (ROO•) enhanced carcinogenesis in rats treated with carcinogen (Sawa et al. Cancer Epidemiol. Biomarkers Prev. 1998, 7, 1007−1012), and the tumor promoting action of ROO• could be reduced by addition of hot-water extracts of vegetables (Maeda et al. Jpn. J. Cancer Res. 1992, 83, 923−928). Here we described the ROO•-scavenging activity of flavonoids and nonflavonoid phenolics and their role in anti-tumor-promoter effects. A model molecular species, ROO•, was generated from tert-butyl hydroperoxide (t-BuOOH) and heme iron, and the scavenging of t-BuOO• was determined by (a) bioassay based on the bactericidal action of ROO•, (b) luminol-enhanced chemiluminescence, and (c) electron spin resonance. Of 17 authentic plant phenolics tested, 9 compounds (including rutin, chlorogenic acid, vanillin, vanillic acid, neohesperidin, gallic acid, shikimic acid, rhamnetin, and kaempferol) showed remarkably high ROO•-scavenging activity. Some of them were detected and quantif...
362 citations
TL;DR: It is suggested that CP plays an important catalytic role in RS-NO formation, which may contribute to its potent antioxidant and cytoprotective activities in vivo in mammalian biological systems.
199 citations
TL;DR: HO-1 expression in the solid tumour may confer resistance of tumour cells to hypoxic stress as well as to NO-mediated cytotoxicity, and it is of great importance that an HO inhibitor, zinc protoporphyrin IX injected intra-arterially to the solid tumor suppressed the tumour growth to a great extent.
Abstract: Induction of haem oxygenase-1 (HO-1) as well as nitric oxide (NO) biosynthesis during tumour growth was investigated in an experimental solid tumour model (AH136B hepatoma) in rats. An immunohistochemical study showed that the inducible isoform of NO synthase (iNOS) was localized in monocyte-derived macrophages, which infiltrated interstitial spaces of solid tumour, but not in the tumour cells. Excessive production of NO in the tumour tissue was unequivocally verified by electron spin resonance spectroscopy. Tumour growth was moderately suppressed by treatment with either Nω-nitro-L-arginine methyl ester (L-NAME) or S-methylisothiourea sulphate (SMT). In contrast, HO-1 was found only in tumour cells, not in macrophages, by in situ hybridization for HO-1 mRNA. HO-1 expression in AH136B cells in culture was strongly enhanced by an NO (NO+) donor S-nitroso-N-acetyl penicillamine. HO-1 mRNA expression in the solid tumour in vivo decreased significantly after treatment with low doses of NOS inhibitors such as L-NAME and SMT (6–20 mg kg−1). However, the level of HO-1 mRNA in the solid tumour treated with higher doses of NOS inhibitor was similar to that of the solid tumour without NOS inhibitor treatment. Strong induction of HO-1 was also observed in solid tumours after occlusion or embolization of the tumour-feeding artery, indicating that ischaemic stress which may involve oxidative stress triggers HO-1 induction in the solid tumour. Lastly, it is of great importance that an HO inhibitor, zinc protoporphyrin IX injected intra-arterially to the solid tumour suppressed the tumour growth to a great extent. In conclusion, HO-1 expression in the solid tumour may confer resistance of tumour cells to hypoxic stress as well as to NO-mediated cytotoxicity. © 1999 Cancer Research Campaign
191 citations
TL;DR: The observations support the hypothesis that the ability of HU to ease the vaso-occlusive phenomena may, in part, be attributed to vasodilation and/or decreased platelet activation induced by HU-derived nitric oxide well in advance of increased HbF levels.
Abstract: The clinical efficacy of hydroxyurea (HU) in the treatment of sickle cell anemia has mainly been attributed to increased levels of fetal hemoglobin (HbF), which reduces the tendency for sickle hemoglobin to polymerize, thereby reducing the frequency of the vaso-occlusive phenomena associated with the disease. However, benefits from HU treatment in patients have been reported in advance of increased HbF levels. Thus, it has been suggested that other hydroxyurea-dependent mechanisms may, in part, account for its clinical efficacy. We have previously demonstrated that HU is metabolized in rats to release nitric oxide and, therefore, postulated the same to occur in humans. However, to our knowledge, evidence of nitric oxide production from HU metabolism in humans has yet to be demonstrated. Here we report that oral administration of HU for the treatment of sickle cell anemia produced detectable nitrosyl hemoglobin. The nitrosyl hemoglobin complex could be detected as early as 30 min after administration and persisted up to 4 h. Our observations support the hypothesis that the ability of HU to ease the vaso-occlusive phenomena may, in part, be attributed to vasodilation and/or decreased platelet activation induced by HU-derived nitric oxide well in advance of increased HbF levels.
118 citations
TL;DR: High level of NO produced by iNOS is a pathogenic factor in HSV-1-induced encephalitis in rats, and treatment of virus-infected animals with the NOS inhibitor Nomega-monomethyl-l-arginine significantly ameliorated not only clinical symptoms such as paralysis and seizures but also mortality.
108 citations
TL;DR: In this paper, the authors described the mechanism of enhancement of vascular permeability in infectious disease and cancer, which is primarily mediated by bradykinin, nitric oxide and other unique vascular mediators.
77 citations
TL;DR: The impact of radical prostatectomy on patient QOL 12 months or longer after surgery and the need for further study is evaluated.
Abstract: Background: Increasingly, quality of life (QOL) assessments are receiving greater attention in the management of malignancies, including prostate cancer. We evaluated the impact of radical prostatectomy on patient QOL 12 months or longer after surgery.
Patients and Methods: We evaluated the impact of radical prostatectomy on QOL in 60 patients with prostate cancer. The patients comprised two groups: the first group (n = 32) was evaluated 12 months or longer after radical prostatectomy; the second group (n = 28) was evaluated while awaiting radical prostatectomy. General health-related QOL was measured with the European Organization for Research and Treatment of Cancer Prostate Cancer QOL Questionnaire. Sexual function was assessed with the Sapporo Medical University Sexual Function Questionnaire. A newly developed instrument assessing urinary function was prepared only for the postoperative group.
Results: No differences between the two groups were seen in comparisons of general health-related QOL subscales. Men who underwent surgery reported significant deterioration in sexual function (decreased quality of erection, decreased sexual activity and decreased satisfaction with sex life) than those awaiting surgery. Of the 32 postoperative patients, 26 (81%) did not use pads at all, five (16%) used one or fewer pads per day due to occasional spotting and only one patient (3%) used two to four pads per day to deal with urine dripping. Twenty-six postoperative patients (81%) stated that, given the choice, they would undergo radical prostatectomy again.
Conclusions: General health-related QOL does not appear to be compromised following radical prostatectomy. Patients are willing to accept some morbidity for a perceived survival benefit. Although minimal urinary dysfunction was reported, most patients were dissatisfied with postoperative sexual function. In preoperative counselling, greater emphasis should be placed on the risk of postoperative impotence.
66 citations
TL;DR: The results suggest that excessive production of O(2)(-) and NO occurs in the late allergic response (LAR) in sensitized guinea pigs in vivo, and these two molecules appear to cause airway microvascular hyperpermeability via peroxynitrite formation.
Abstract: We investigated the role of peroxynitrite, which is formed by a rapid reaction between nitric oxide (NO) and superoxide anion (O2 −), in the airway microvascular hyperpermeability during the late allergic response (LAR) in sensitized guinea pigs in vivo. The occurrence of LAR was assessed as a 100% increase in the transpulmonary pressure, which was monitored by the esophageal catheter technique. Airway microvascular permeability was assessed by Monastral blue dye trapping between the endothelium using an image analyzer. In the LAR phase (4 to 6 h after antigen inhalation), microvascular hyperpermeability and eosinophil infiltration within the airway wall were observed. NO production and xanthine oxidase (XO)/xanthine dehydrogenase activity, which are responsible for O2 − production, were enhanced during the LAR. Peroxynitrite formation assessed by nitrotyrosine immunostaining was also exaggerated at that time. The microvascular hyperpermeability during the LAR was largely reduced by NO synthase inhibitor ...
59 citations
TL;DR: cPSA was more specific than tPSA and F/T PSA and as a component of F/C PSA, free PSA could provide additional value to cPSA.
47 citations
TL;DR: Evidence is presented in which O2*- is generated when recombinant human cytochrome b5 reductase (rh-Cytb5Rd) was incubated with HCAs such as IQ and MeIQ in the presence of NADH in vitro, which indicates that free radical generation by rh- Cytb 5Rd in the absence of HCA may add new insight into the damage of DNA.
39 citations
TL;DR: The IS1598 isolated in this study is a novel insertion element which might be a specific marker for virulent P. gingivalis strains and may interrupt the synthesis of the outer membrane protein, resulting in changes in the structure of the bacterial outer membrane.
Abstract: Subtractive hybridization was employed to isolate specific genes from virulent Porphyromonas gingivalis strains that are possibly related to abscess formation. The genomic DNA from the virulent strain P. gingivalis W83 was subtracted with DNA from the avirulent strain ATCC 33277. Three clones unique to strain W83 were isolated and sequenced. The cloned DNA fragments were 885, 369, and 132 bp and had slight homology with only Bacillus stearothermophilus IS5377, which is a putative transposase. The regions flanking the cloned DNA fragments were isolated and sequenced, and the gene structure around the clones was revealed. These three clones were located side-by-side in a gene reported as an outer membrane protein. The three clones interrupt the open reading frame of the outer membrane protein gene. This inserted DNA, consisting of three isolated clones, was designated IS1598, which was 1,396 bp (i.e., a 1,158-bp open reading frame) in length and was flanked by 16-bp terminal inverted repeats and a 9-bp duplicated target sequence. IS1598 was detected in P. gingivalis W83, W50, and FDC 381 by Southern hybridization. All three P. gingivalis strains have been shown to possess abscess-forming ability in animal models. However, IS1598 was not detected in avirulent strains of P. gingivalis, including ATCC 33277. The IS1598 may interrupt the synthesis of the outer membrane protein, resulting in changes in the structure of the bacterial outer membrane. The IS1598 isolated in this study is a novel insertion element which might be a specific marker for virulent P. gingivalis strains.
TL;DR: Changes in intrarenal vascular resistance after ESWL were studied with Doppler ultrasound techniques and brought a new insight into renal function.
Abstract: Background: Extracorporeal shock wave lithotripsy (ESWL) has replaced most surgical and endourologic forms of therapy for upper urinary tract stone disease. Despite its proved safety and efficacy, its adverse effects on renal function are still to be identified. A newer diagnostic technique, color Doppler ultrasonography, has brought a new insight into renal function. It enables precise evaluation of the renal vascular supply. Changes in intrarenal vascular resistance after ESWL were studied with Doppler ultrasound techniques.
Methods: In 70 consecutive patients the resistive index (RI) was measured at an interlober artery before and 30 min after ESWL in the treated and contralateral kidneys. In 17 patients, a follow-up Doppler study was performed 1 week after ESWL.
Results: In the treated kidneys, the RI significantly increased from 0.656 ± 0.053 (mean ± SD) at baseline to 0.682 ± 0.053 (P < 0.0001). There was no significant correlation of increase in RI with patient age (r = 0.010) or with pre-ESWL blood pressure (r = 0.002). Elderly patients (≥ 60 years old, n = 31) had higher RI levels on baseline than younger patients (< 60 years old, n = 39). In 18 of the 31 (58.1%) elderly cases the RI were elevated to greater than 0.7, indicating pathologic changes. In younger patients, only 9 (23.1%) experienced increase in RI up to 0.7 or greater. The contralateral untreated kidneys showed significant change in RI before (0.664 ± 0.045) and after (0.679 ± 0.049) lithotripsy in elderly patients (P < 0.005). A follow-up Doppler study showed that the mean RI returned to pretreatment levels after 1 week.
Conclusions: Because of higher RI levels on baseline, elderly patients have a higher risk of post-ESWL renal tissue damage than younger patients. Clinical implication of RI change in the contralateral kidneys in this study remains to be answered. The measurement of changes in RI with Doppler ultrasound techniques after ESWL may provide useful information for clinical diagnosis of renal tissue damage.
TL;DR: A series of high magnetic fields up to 9 T have been applied to the preparation of Ag-doped Bi2212 bulks and a strong correlation is observed between the field strength and the degree of texture developed in the bulks.
Abstract: A series of high magnetic fields up to 9 T have been applied to the preparation of Ag-doped Bi2212 bulks and a strong correlation is observed between the field strength and the degree of texture developed in the bulks. Two powders of Bi 2.2 Sr 1.8 CuO x and CaCuO 2 were synthesized separately and then 10 wt.% Ag was doped to their equimolar mixture, from which the Bi2212 bulks were formed by a partial melt–solidification process in the high magnetic fields. The degree of texture in the bulks was evaluated quantitatively by X-ray diffraction and magnetization measurement. It is found that the applied magnetic fields tend to orient Bi2212 grains with their c -axis parallel to them and obvious texture exists in all samples prepared in the magnetic fields; while in samples prepared without magnetic field Bi2212 grains orient randomly. In the field range of 0–9 T, the degree of texture increases notably with increasing the magnetic field. In 9 T Bi2212, bulks with magnetization anisotropy factor more than four and a density of 6.15 g/cm 3 are obtained and SEM observation also shows a highly oriented grain alignment.
TL;DR: To detect endogenous nitric oxide produced in a rat bacterial meningitis model, an electron paramagnetic resonance (EPR) NO-trapping technique was applied and Inducible NO synthase mRNA expression in the brain tissues also was proven by using a reverse transcriptase-polymerase chain reaction technique.
Abstract: To detect endogenous nitric oxide (NO) produced in a rat bacterial meningitis model, the authors applied an electron paramagnetic resonance (EPR) NO-trapping technique. Iron complex with N,N-diethyldithiocarbamate were used as a trapping agent. Experimental meningitis was induced by a mixture of lipopolysaccharide and interferon-γ. Sequential changes of NO formation under meningitis were observed in rat brain tissue by using X-band (9 GHz) EPR spectroscopy, and endogenous NO was detected in the head of a living rat with a 700-MHz EPR system. Inducible NO synthase mRNA expression in the brain tissues also was proven by using a reverse transcriptase-polymerase chain reaction technique.
TL;DR: A highly sensitive method for measurement of urinary hyaluronan with a minimum molecular mass of 2,000 Da was developed without using HPLC or radioisotopes and sex difference of urinary Hyaluronans was not observed both quantitatively or qualitatively.
Abstract: A highly sensitive method for measurement of urinary hyaluronan with a minimum molecular mass of 2,000 Da was developed without using HPLC or radioisotopes. This competitive enzyme-linked immunosorbent assay-like method, used competitive binding of free hyaluronan in the sample and biotin-labeled standard hyaluronan to hyaluronan binding protein in solid phase. A total of 150 healthy individuals from both sexes at ages from 0 to 100 years was examined by the established method. Hyaluronan of 384±80 ng/mg creatinine (mean±SD) was constantly excreted into urine of 24-40-year-old healthy adults. The urinary hyaluronan levels were significantly higher before age 1 (p<0.001) and rather high after 90 years compared to the other groups. The average molecular weight of urinary hyaluronan (5,500 Da) was constant through all generations. Sex difference of urinary hyaluronan was not observed both quantitatively or qualitatively.
29 Dec 1999
TL;DR: It is suggested that Qing Fei Tang pretreatment can reduce oxygen radical production in inflammed lungs and may reduce the mortality for aspiration pneumonia.
TL;DR: An important role is suggested in the combined effects of gastric juice and bacteria on pneumonia, as XO activity raised by Streptococcus pneumoniae and gastric Juice was significantly reduced by pyran-SOD.
TL;DR: A 43‐year‐old woman who had been using intrauterine contraceptive devices for the past 10 years underwent an emergency operation for bowel and urinary obstruction.
Abstract: A 43-year-old woman who had been using an IUD for the past 10 years underwent an emergency operation for bowel and urinary obstruction. Frozen section analysis showed undifferentiated adenocarcinoma. Incomplete tumorectomy ileal resection partial cystectomy colostomy and bilateral ureterocutaneostomy were palliatively performed. Postoperatively periodic acid-Schiff and Grocott-Gomori methenamine tests revealed Actinomyces and the final diagnosis was pelvic actinomycosis. Treatment with penicillin G administered intravenously relieved her symptoms and the lesion was dramatically improved. The patient underwent colostomy closure and urinary undiversion. 5 years after urinary undiversion the patients renal function has been maintained and she can void without incontinence and dysuria. (authors)
TL;DR: In this paper, a high critical current density of 29000A/cm/sup 2/ (77 K, 0 T) has been achieved in rolled tape with Ag-alloy sheath, in this case the critical current of the tapes is 81.5A, which is higher than that of multifilamentary tapes with pure Ag sheath.
Abstract: (Bi,Pb)-2223 tapes with 37 filaments have been fabricated by powder in tube (PIT) method. Silver was used for the sheath of filaments and the Ag-Mn-Ni alloy was used for the outer sheath of the tapes. A high critical current density of 29000A/cm/sup 2/ (77 K, 0 T) has been achieved in rolled tape with Ag-alloy sheath, in this case the critical current of the tapes is 81.5A, which is higher than that of multifilamentary tapes with pure Ag sheath prepared by the same process. The precursor powders prepared by mixing the (Bi,Pb)-2212 and CaCuO/sub 2/ has been considered to be beneficial for fabricating high J/sub c/ multifilamentary tapes with Ag-alloy sheath. The superconducting properties and microstructural characteristics of the multifilamentary tapes have been investigated in this work.
TL;DR: In this paper, the powder-in-tube method was used to prepare Ag-sheathed mono-core tapes and multifilamentary tapes with 19 filaments by using V- and Ir-doped Bi2223 powder with a doping amount x less than 0.15.
Abstract: We prepared Ag-sheathed mono-core tapes and multifilamentary tapes with 19 filaments by the powder-in-tube method, using V- and Ir-doped Bi2223 powder with a doping amount x less than 0.15. In the doped tapes two effects are overlapped: One is the decrease in J/sub c/ due to some weak links caused by precipitates such as Sr-V-O oxides, and the other is the increase in J/sub c/ with the doping content due to the enhancement of Bi2223 phase formation. This results in a minimum in J/sub c/ at x=0.05. The second effect becomes stronger in the V-doping, because of the great enhancement of Bi2223 phase formation. In the Ir-doped tapes the J/sub c/ values decrease monotonically with the doping content. For the multifilamentary tapes the V-doping is very effective to obtain high I/sub c/ values.
TL;DR: In this paper, the antidiarrheal action of Zaldaride maleate (ZAL) after oral, intravenous and subcutaneous administration was examined to determine whether ZAL acts systemically or locally in the intestine of rats.
TL;DR: A case in which the completely obstructed ureter was successfully treated by endourological procedure and the patient presented no recurrence at 2-year follow up.
Abstract: We report a case in which the completely obstructed ureter was successfully treated by endourological procedure. The patient was a 66-year-old male who had been admitted for panperitonitis caused by diverticulitis perforation of the sigmoid colon. About one month later, leakage of both stool and urine and left hydronephrosis were observed. Therefore, left percutaneous nephrostomy was performed and the artificial anus was created. Radiographic examination showed about 1 cm defect on the lower one-third of the left ureter. (1st Operation) A 9.5 Fr. rigid ureteroscope was inserted into the left ureter transurethrally and a 7.5 Fr. flexible ureteroscope was inserted percutaneously. Antegrade puncture using a stiff end of a 0.038-inch guidewire into the obstructed segment was failed. Then, we bit off the obliterated tissue with a biopsy forceps transurethrally towards the light from the flexible scope, and a 12 Fr. double-J stent was indwell. (2nd Operation) Eight weeks after the first operation, a 12 Fr. ureteroresectoscope was inserted transurethrally. Full-thickness cold-knife incision of the re-established ureter was failed, however. (3rd Operation) Two weeks after the second operation, a 12.5 Fr. ureteroscope was inserted transurethrally, and a full-thickness incision in the lateral position of the re-established ureter was successfully made by KTP-laser. Then, a 12 Fr. endopyelotomy stent was placed. (Result) Six weeks after the third operation, the stent was removed and DIP revealed the improvement in hydronephrosis. The patient presented no recurrence at 2-year follow up.
01 Jan 1999
TL;DR: In this paper, a powder in tube (PIT) method with a rectangular deformation was used to produce pure silver foils of thickness about 15μm and precursor powder prepared by mixing the (Bi,Pb)-2212, Ca2CuO3 and CuO powders.
Abstract: The silver foils have been introduced into (Bi,Pb)-2223 multifilamentary tapes to improve their superconducting properties. The tapes are fabricated by powder in tube (PIT) method with a rectangular deformation. Pure silver foils of thickness about 15μm and precursor powder prepared by mixing the (Bi,Pb)-2212, Ca2CuO3 and CuO powders are parallelly packed into a rectangular Ag tube. The thickness and size of the Ag foils in the composites can be reduced significantly during the cold working. A transport Jc value of 2.6 x 104 A/cm2 (77K, 0T) has been obtained, and the Jc-B dependence is improved compared with the ordinary 37 filaments’ tape without Ag foil in the case of applied field parallel to the tape surface.
01 Jan 1999
TL;DR: The magnetic field has a tendency to orient the grains with their c-axes parallel to it and the bulk ceramics has an anisotropy of about a factor of two in magnetization.
Abstract: Bi2212 tapes and bulks were heat-treated in high magnetic fields HA up to 10T. Obvious texture is developed in Pb-doped Bi2212 bulk ceramics by solidification from partial melting in a HA of 9T. The magnetic field has a tendency to orient the grains with their c-axes parallel to it and the bulk ceramics has an anisotropy of about a factor of two in magnetization. Magnetic field is also found to have influences on the transport critical current density Jc of dip-coated Bi2212/Ag tapes. The difference in Jc between the tapes placed perpendicular to the magnetic field and ones parallel to it increases with increasing the HA except 10T.