Biomedical subjects

S Kudo

Publications and source records attributed to S Kudo.

At least 19 recordsLinked to original sources

PubMed1999

Association and dissociation properties of natural human interferon gamma.

The properties of natural human interferon gamma (IFN-gamma) molecules dissolved in protein-denaturing and non-denaturing solvents were examined by high-performance size-exclusion chromatography on a gel permeation column. IFN-gamma and tritium-labeled IFN-gamma molecules formed either dimers (>90.5%) with the molecular mass of 60 kDa or probably tetramers (<9.5%) with the molecular mass of approximately 100 kDa in non-denaturing solvents, and no monomer was detected. These oligomers were dissociated in protein-denaturing solvents such as 6 M guanidine hydrochloride, and IFN-gamma existed as monomers. There is no effect on formation of the monomer based on the dissociation of oligomers by acid treatment at pH 4.0. The monomers in protein-denaturing solvents formed dimers by association when applied to a column equilibrated with a non-denaturing solvent of phosphate buffer, pH 7.0. In conclusion, natural human IFN-gamma forms oligomers, particularly dimers, in non-denaturing solution, and this oligomer formation is a reversible reaction.

Cell Line↗

PubMed1999

A study on the effects of endogenous nitric oxide on coronary blood flow, myocardial oxygen extraction and cardiac contractility.

The purpose of the present study was to clarify how endogenous nitric oxide (NO) affects cardiac contractility and myocardial oxygen consumption (MVO2) in vivo. alpha-Chloralose-anesthetized dogs (n = 18) were instrumented to perform continuous and simultaneous measurements of coronary blood flow (CBF), anterior interventricular vein oxygen saturation (with the use of a fiberoptic catheter), aortic pressure, left ventricular pressure, and left ventricular volume. CBF, myocardial oxygen extraction (O2-extract), MVO2, the relationship between CBF and O2-extract during direct vasodilation induced by intracoronary papaverine (0.1, 0.2, 0.4 mg/kg), and cardiac contractility (Emax) were examined at control, after intracoronary infusion of NG-monomethyl-L-arginine (L-NMMA, 2 mg/kg) and after antagonization of NO by L-arginine (20 mg/kg). L-NMMA decreased CBF from 62.0 +/- 1.7 to 59.7 +/- 2.4 (mL/min/100 g, P < 0.05) and increased O2-extract from 68.2 +/- 1.7 to 79.0 +/- 1.7% (P < 0.05). Emax was increased after L-NMMA from 3.2 +/- 0.2 to 3.7 +/- 0.1 (mmHg/mL/100 g, P < 0.05). These effects of L-NMMA were antagonized by L-arginine (P < 0.05 vs. after L-NMMA, P = NS vs. before L-NMMA). L-NMMA shifted CBF and O2-extract relationship determined by papaverine injection upward and L-arginine antagonized it to its baseline level. Endogenous NO reduces cardiac contractility and decreases MVO2, while increasing CBF.

Animals↗

PubMed1999

The clinical epidemiological investigation of diagnostic modalities in breast cancer detection--a comparison of ultrasonography and mammography.

We reviewed the medical records and images of 39 women with palpable breast masses, including 18 cases with breast cancer and 21 cases with benign breast mass, to compare diagnostic accuracy and clinical agreement between ultrasonography and mammography in breast cancer detection. We showed that the operating characteristics of ultrasonography, including sensitivity, specificity and positive likelihood ratio, were superior to that of mammography. We also confirmed that the established malignant criteria for malignancy, including lobulated shape, irregular contour and non-uniform internal echo in ultrasonography, and stellate mass in mammography, were statistically significant in distinguishing breast cancer from benign breast lesion. Moreover, the interobserver agreement kappa of ultrasonography and mammography were 0.64 and 0.59, respectively. Ultrasonography was also superior to mammography in attaining clinical agreement between the different observers in breast cancer detection.

Breast Neoplasms↗

PubMed1999

Cytochrome P-450 isoforms involved in carboxylic acid ester cleavage of Hantzsch pyridine ester of pranidipine.

Cytochrome P-450 (CYP) isoforms responsible for the cleavage of Hantzsch pyridine ester at the 3-position of pranidipine were studied in vitro using cDNA-expressed human CYP enzymes. CYP1A1, 1A2, 2D6, and 3A4 cleaved the ester with a catalytic activity of 5.5, 0. 93, 13.1, and 22.4 nmol/30 min/nmol P-450, respectively. CYP2A6, 2B6, 2C8, 2C9, 2C19, and 2E1 were not involved in the de-esterification. The Km and Vmax values for the de-esterification were 11.8 microM and 0.47 nmol/min/nmol P-450 in the CYP2D6-catalyzed reaction and 8. 7 microM and 0.84 nmol/min/nmol P-450 in the CYP3A4-catalyzed reaction. The intrinsic clearance (Vmax/Km) of the de-esterification by CYP3A4 was 2-fold greater than that by CYP2D6. Quinidine almost completely inhibited the CYP2D6-mediated de-esterification at the concentration of 1 x 10(-6) M. Ketoconazole and troleandomycin inhibited the CYP3A4-mediated reaction in a dose-related manner. The results indicate that although the multiple CYP isoforms can catalyze the de-esterification, CYP3A4 and 2D6 are the major isoforms.

Biotransformation↗

PubMed1998

Role of sperm head syndecan at fertilization in fish.

Fish sperm head plasma membranes have been demonstrated to contain syndecan (transmembrane heparan sulfate proteoglycan) immunofluorohistochemically and using immunoblot analysis and transglutaminase (TGase) by histochemistry. In order to examine the involvement of syndecan in fertilization, mature eggs were inseminated by direct mixing with untreated sperm or with sperm pretreated with an antiheparan sulfate (HS) antibody monoclonal (mAb), bovine serum albumin, human transferrin, or a TGase inhibitor (monodansylcadaverine, cystamine, and iodoacetamide). The fertilization rates of eggs inseminated with untreated and albumin-pretreated sperm were approximately 99.3% and 94.7%, respectively. Those of eggs pretreated with the anti-HS antibody and transferrin were 0% and 5.4%, respectively, whereas use of sperm pretreated with TGase inhibitors resulted in fertilization rates of approximately 13.2-17.8%. These results indicate that sperm head syndecan play an important role in fish sperm-egg contact and/or binding and that TGase inhibitors may reduce the fertilization rate by inhibiting sperm motility.

Animals↗

PubMed1998

Involvement of human cytochrome P450 3A4 in reduced haloperidol oxidation.

OBJECTIVE: The present study was conducted to identify in vitro the cytochrome P450(CYP) isoform involved in the metabolic conversion of reduced haloperidol to haloperidol using microsomes derived from human AHH-1 TK +/- cells expressing human cytochrome P450s. The inhibitory and/or stimulatory effects of reduced haloperidol or haloperidol on CYP2D6-catalyzed carteolol 8-hydroxylase activity were also investigated. RESULTS: The CYP isoform involved in the oxidation of reduced haloperidol to haloperidol was CYP3A4. CYP1A1, 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 2E1 were not involved in the oxidation. The kM value for the CYP3A4 expressed in the cells was 69.7 micromol x l(-1), and the Vmax was 4.87 pmol x min(-1) x pmol(-1) P450. Troleandomycin, a relatively selective probe for CYP3A enzymes, inhibited the CYP3A4-mediated oxidation of reduced haloperidol in a dose-dependent manner. Quinidine and sparteine competitively inhibited the oxidative reaction with a k(i) value of 24.9 and 1390 micromol x l(-1), respectively. Carteolol 8-hydroxylase activity, which is a selective reaction probe for CYP2D6 activity, was inhibited by reduced haloperidol with a k(i) value of 4.3 micromol x l(-1). Haloperidol stimulated the CYP2D6-mediated carteolol 8-hydroxylase activity with an optimum concentration of 1 micromol x l(-1), whereas higher concentrations of the compound (> 10 micromol x l(-1)) inhibited the hydroxylase activity. CONCLUSION: It was concluded that CYP3A4, not CYP2D6, is the principal isoform of cytochrome P450 involved in the metabolic conversion of reduced haloperidol to haloperidol. It was further found that reduced haloperidol is a substrate of CYP3A4 and an inhibitor of CYP2D6, and that haloperidol has both stimulatory and inhibitory effects on CYP2D6 activity.

Anti-Arrhythmia Agents↗

PubMed1998

Cystic dilatation of ventriculus terminalis in adults: MRI.

We report the MRI findings in two patients with cystic dilatation of the ventriculus terminalis. The latter is usually a tiny ependyma-lined cavity of the conus medullaris. In both cases the markedly dilated ventriculus terminalis was seen as a rounded cavity with regular margins, the content of which gave the same signal as cerebrospinal fluid with all MR pulse sequences. No contrast enhancement was seen.

Adult↗

PubMed1998

Activity of gemcitabine in non-small-cell lung cancer: results of the Japan gemcitabine group (A) phase II study.

PURPOSE: This phase II study was conducted to determine the response and toxicity of gemcitabine (2',2'-difluorodeoxycytidine) in chemotherapy-naive patients with non-small-cell lung cancer (NSCLC). METHODS: A group of 73 patients were entered into the study. The patients had received no previous chemotherapy and all had measurable disease. The initial starting dose of gemcitabine was 1000 mg/m2 per week x 3 followed by a week of rest, and was escalated for the next cycle to 1250 mg/m2, provided there were no signs of hematologic toxicity (WBC < 3000/microl and/or platelets < 70,000/microl) in the previous cycle. RESULTS: Among 73 eligible patients, there were 19 partial responses (PRs), with an overall response rate of 26.0% (95% confidence interval 16.5-37.6%). The response rate for stage IIIa and IIIb disease was significantly higher than that for stage IV disease [41.4% (12/29) vs 15.9% (7/44); P = 0.028]. The median duration of response in patients showing a PR was 4.6 months (1.7 10.4 months). The median number of cycles given was two per patient (range one to seven). Grade 3 anemia, leukopenia and neutropenia occurred in 15 patients (20.5%), 7 patients (9.6%) and 20 patients (27.4%), respectively. Grade 3 thrombocytopenia occurred in one patient (1.4%) which was not associated with any bleeding. There was no evidence of cumulative toxicity in the later courses of gemcitabine treatment with regard to leukopenia and thrombocytopenia. Other toxicities, including hepatic toxicity, fatigue, nausea/vomiting and fever were mild (grade 2 or less) and transient. One patient was withdrawn from the trial because of a rash. Pulmonary toxicity was experienced in two patients and one patient died of respiratory insufficiency which was thought to be drug-related. CONCLUSIONS: Gemcitabine as a single agent has proven to be an active drug for NSCLC with a favorable, generally mild side-effect profile. Further trials in combination with other agents for this disease are currently underway.

Adult↗

PubMed1998

High-pressure liquid chromatographic determination of toluene in urine as a marker of occupational exposure to toluene.

OBJECTIVE: To establish a convenient method by high-pressure liquid chromatography (HPLC) to measure toluene in urine as a marker of occupational exposure to toluene. METHODS: As soon after sampling as possible, 1 ml of urine was mixed with an equal volume of acetonitrile in a 2.2-ml HPLC glass bottle, and the bottle was tightly sealed and stored at 4 degrees C. Immediately before HPLC determination, 100 microl methanol was added to the mixture to prevent confounding effects of glycosuria, and the bottle was spun to remove any suspended matter. An aliquot of the supernate was introduced into the HPLC system and analyzed on a PRODIGY column, with an acetonitrile - perchloric acid phosphoric acid - water mixture serving as the mobile phase. The effluent was monitored at 191 nm. RESULTS: The method can measure toluene in urine every 20 min, the detection limit was 2 microg/l, the coefficient of variation was less than 5%, and the recovery rate was 100%. No significant reduction in toluene concentration was observed for 1 week after storage at 4 degrees C. When the method was applied to end-of-shift urine samples from 13 male workers exposed to toluene at 18-140 ppm and also to urine samples from 10 nonexposed male controls, toluene in urine was linearly related to toluene exposure concentration, with a regression line passing close to the origin. The correlation coefficient was as high as 0.97 (n=23). No toluene was detected in control urine samples. Calculations suggest that urinary toluene accounts for as little as less than 0.01% of the toluene absorbed via inhalation and that the absorbed toluene is converted almost quantitatively to hippuric acid and, by less than 0.1%, to o-cresol.

Adult↗

PubMed1998

Assembly in vitro of vitelline envelope components induced by a cortical alveolus sialoglycoprotein of eggs of the fish Tribolodon hakonensis.

Assembly in vitro of vitelline envelope (VE) components, which were precipitated by 50-70% saturated ammonium sulphate from VE extracts, was induced by the action of a sialoglycoprotein that is immunohistochemically localised in cortical alveoli of fish eggs and has serine proteinase activity. The VE components consisted of major bands of molecular mass about 150-120, 110-100, 70 and 27 kDa in addition to about 20 minor bands and contained a chorionic transglutaminase, visualised as two fluorescent bands by monodansylcadaverine staining. The VE component assembly in vitro was Ca(2+)-dependent, not induced if the sialoglycoprotein was pretreated with a serine proteinase inhibitor, and inhibited by the presence of p-chloromercuribenzoate, iodoacetamide or L-cysteine in the reaction medium system. Electron microscopy revealed that assembly in vitro of the VE components consisted of aggregates of network sheets, consisting of branching and anastomosing thin (approximately 27-52 nm) and thick (approximately 137-376 nm) filamentous substances. Separation by SDS-PAGE showed that a considerable number of VE components participated in the assembly in vitro in various amounts. These results suggest at least partial reproduction of the phenomena that occur in the process of fertilisation envelope (FE) formation, and provide a new approach to investigation of the process of FE assembly in vitro.

Animals↗

PubMed1998

Metabolism of 1-(3,4-dichlorobenzyl)-5-octylbiguanide in the dog.

1. The biotransformation of 1-(3,4-dichlorobenzyl)-5-octylbiguanide (OPB-2045), a new potent biguanide antiseptic, was investigated in male beagle dogs. Urinary and faecal excretion of unchanged compound and metabolites were studied following a single subcutaneous injection of 14C-labeled compound at a dose of 1 mg/kg. 2. Four urinary metabolites were structually identified using synthetic standards and/or spectral data as 3,4-dichlorobenzoic acid, 6-[5-(3,4-dichlorobenzyl)-1-biguanidino] hexanoic acid (DM-210), 4-[5-(3,4-dichlorobenzl)-1-biguanidino] butanoic acid (DM-212) and 5-[5-(3,4-dichlorobenzyl)-1-biguanidino] pentanoic acid (DM-213). 3. The predominant radioactive substances in the excreta were DM-213 and DM-210 at 26.1% and 25.5%, respectively, of the dose. No unchanged compound was detected in the urine, and in the faeces it was only 2% of the dose.

Animals↗

PubMed1998

High-performance liquid chromatography-electrospray tandem mass spectrometry for the measurement of 1-(3,4-dichlorobenzyl)-5-octylbiguanide in human serum.

1-(3,4-dichlorobenzyl)-5-octylbiguanide (OPB-2045) is a new biguanide antimicrobial agent currently in clinical use as a topical bactericidal antiseptic. A method combining high-performance liquid chromatography (HPLC) with electrospray ionization (triple and quadruple stage) tandem mass spectrometry (ESI-MS/MS) was developed to quantify OPB-2045 in human serum. Solid phase extraction was performed on 0.2 ml of sample to ensure a high level of sensitivity before HPLC-ESI-MS/MS analysis. The limit of quantitation for the method was set at 0.05 ng/ml. Intra-assay and interassay precision were less than 13.7%, with a deviation from the expected value of no greater than 10.5% at a concentration range of 0.05 ng/ml to 5 ng/ml. Decomposition of OPB-2045 in human serum did not occur after storage for 15 months at -20 degrees C, even after three repetitions of freezing and thawing. Application of this method was demonstrated in a pharmacokinetic study of OPB-2045 in healthy patient subjects after a single topical application of 5 g/L preparation of its liquid formulation.

Adult↗

PubMed1998

Methyl-CpG-binding protein MeCP2 represses Sp1-activated transcription of the human leukosialin gene when the promoter is methylated.

Human leukosialin (CD43) is expressed in a cell lineage-specific as well as a differentiation stage-specific fashion. The leukosialin promoter, made up of an Sp1 binding site and a sequence similar to that of an initiator, possesses high transcriptional potential. Previous data have demonstrated that the leukosialin gene is down-regulated in nonproducing cells by DNA methylation. In this paper the repressive mechanism of DNA methylation in expression systems is reported. In vitro DNA methylation with SssI (CpG) methylase of leukosialin-chloramphenicol acetyltransferase (CAT) constructs drastically reduced transcriptional activities in stable transfection systems with the human HeLa and Jurkat cell lines. On the other hand, the transcriptional repression by in vitro methylation was less pronounced in Drosophila melanogaster cells, which lack genomic methylation. In these cells, Sp1 could transactivate equally well both the unmethylated and methylated leukosialin promoter. In order to test whether one of the methyl-CpG-binding proteins, MeCP2, is responsible for transcriptional repression of the leukosialin gene, I isolated the human MeCP2 cDNA (encoding 486 amino acid residues) and expressed it in Drosophila cells. I found that MeCP2 substantially inhibited Sp1-activated transcription when the leukosialin promoter was methylated. The level of repression was directly proportional to the amount of MeCP2 expression vector transfected. Analysis of C-terminal deletion mutants of MeCP2 showed that repressive activity of Sp1 transactivation is localized to the N-terminal region consisting of amino acid residues 1 to 193, which encompass the methyl-binding domain. These results suggest that interference with Sp1 transactivation by MeCP2 is an important factor in the down-regulation of leukosialin gene expression by DNA methylation.

Antigens, CD↗

PubMed1998

Flat adenomas exist in asymptomatic people: important implications for colorectal cancer screening programmes.

BACKGROUND: Flat adenomas are non-exophytic with a flat top or central depression and histologically the depth of dysplastic tissue is never more than twice the mucosal thickness. Flat adenomas frequently contain severely dysplastic tissue, and may progress rapidly through the adenoma-carcinoma sequence. Flat lesions have never been described in a British asymptomatic population. AIMS: To determine whether flat adenomas exist in an asymptomatic population participating in a large randomised controlled trial of flexible sigmoidoscopy screening. PATIENTS: A total of 3000 subjects (aged 55-64 years) underwent screening by flexible sigmoidoscopy. METHODS: All polyps were removed and sent for histology. The number of polyps with endoscopic and histological features of flat adenomas was recorded. RESULTS: Three subjects had a total of four flat lesions--that is, one per 1000 people screened. Three contained severely dysplastic tissue, one a focus of adenocarcinoma. Three of the four lesions were less than 5 mm in size and the fourth was 15 mm in diameter. CONCLUSIONS: Flat lesions with severe dysplasia exist in the asymptomatic population. This has major implications for gastroenterologists who should be trained to identify them. Their existence is of importance to molecular biologists and epidemiologists investigating the aetiology of colorectal cancer.

Adenomatous Polyps↗

PubMed1998

Effect of autotransplantation of microvessel fragments on experimental random-pattern flaps in the rat.

We examined whether autotransplantation of microvessel fragments (Mvf) and/or myofibroblasts (Mf) into an in vivo skin flap model might improve the survival of the ischemic flap. If so, this could improve blood perfusion, increase blood flow, and improve the survival of the flap. A skin flap was raised on the back of each rat (n = 15 in each group). In the control group, the flap was sutured to the original bed. In the other groups (1) phosphate-buffered saline; (2) autotransplanted Mvf, Mf, or Mvf plus Mf, and (3) a homogenized mixture of Mvf plus Mf was injected into the distal part of the flap. In a further group, Mvf labeled with DiI-acetylated low-density lipoprotein were autotransplanted with Mf into the distal part of the flap, and India ink was perfused through the abdominal aorta 7 days postoperatively. The transplanted Mvf plus Mf group showed better flap survival after 7 days than the other groups (p < 0.02). Labeling with DiI-acetylated low-density lipoprotein showed that transplanted Mvf sent arborizations into the nearby tissue. India ink was found in the lumina within such arborizations. Thus, autotransplanted Mvf may improve the survival of ischemic skin flaps by promoting the early formation of patent connections between Mvf and the host's microcirculatory system. This apparently requires the presence of Mf.

Animals↗

PubMed1998

Retroperitoneal fibrosis with perinuclear antineutrophil cytoplasmic antibodies and a longitudinally extended periaortic soft-tissue structure on CT.

A 63-year-old woman showed positive perinuclear antineutrophil cytoplasmic antibodies (pANCA) and presented with an interesting CT finding of a periaortic soft-tissue structure seen as a rind of tissue surrounding the aorta, extending longitudinally from descending thoracic aorta to bilateral common iliac arteries which was compatible with an early stage of retroperitoneal fibrosis (RPF). Both pANCA titers and a periaortic mass volume were reduced following corticosteroid treatment. No cases of RPF with a periaortic mass associated with pANCA have been described. Our findings of RPF with pANCA positivity may enlarge the groups of ANCA-associated diseases.

Antibodies, Antineutrophil Cytoplasmic↗

PubMed1998

[The effects of interferon-alpha on oxygen radical production by human neutrophils].

This study was done to determine if the production and metabolism of reactive oxygen species from human neutrophils were modulated by the treatment of interferon-alpha (IFN-alpha). Luminol-dependent Chemiluminescence (LmCL) responses were inhibited by a high concentration of IFN-alpha (more than 1 x 10(4) IU/ml) when opsonized zymosan (OZ) and phorbol 12-myristate 13-acetate (PMA) were used as stimulants. However, these responses were increased by 1 x 10(3) IU/ml of IFN-alpha with Ca(2+)-ionophore A23187 stimulation. Lucigenin-dependent Chemiluminescence (LgCL) responses were inhibited by all concentrations. These findings suggest the possibility that IFN-alpha inhibits activation of protein kinase C (PKC), whereas the resulting effect might be due to the inhibition of myeloperoxidese (MPO) degranulation. Preincubation of human neutrophils with IFN-alpha for 30, 60 or 120 minutes and subsequent stimulation with OZ, PMA and Ca(2+)-ionophore A23187 caused an increase LgCL responses, while inhibiting LmCL responses. These findings suggest that preincubation of human neutrophils with a high concentration of IFN-alpha might enhance the NADPH-oxidase activity, although a relative increase of LgCL was due to the inhibition MPO degranulation.

Acridines↗

PubMed1998

Pleomorphic adenoma of the salivary glands: correlation between gallium-67 uptake and histopathological components.

UNLABELLED: We correlated 67Ga uptake and histopathological findings in pleomorphic adenomas of the salivary glands. METHODS: Sixty-two pleomorphic adenomas of the salivary glands were visually graded by degree of 67Ga uptake as negative, weakly positive or strongly positive in comparison to uptake in the nasal cavity. These adenomas were re-examined pathologically and classified as epithelial, intermediate or mesenchymal type according to their dominant histological components. The pathological presence of marginal invasion or associated sialoadenitis was also re-examined. RESULTS: Eighteen adenomas were classified as strongly positive, eight as weakly positive and 36 as negative. Nine (50%) of the 18 strongly positive adenomas were of the epithelial type and the other nine (50%) strongly positive adenomas were of the intermediate type. While none of the strongly positive adenomas were of the mesenchymal type, 27 (75%) of the 36 negative adenomas were of the mesenchymal type. Six (75%) of the eight weakly positive adenomas were of the intermediate type. About half of the adenomas showed marginal invasion regardless of the grade of 67Ga uptake. None of the strongly positive adenomas were associated with sialoadenitis. CONCLUSION: The epithelial component of pleomorphic adenomas may be responsible for 67Ga uptake. The presence of marginal invasion or associated sialoadenitis has little relation to 67Ga uptake in pleomorphic adenomas.

Adenoma, Pleomorphic↗