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S Kudo

Publications and source records attributed to S Kudo.

At least 19 recordsLinked to original sources
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

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

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

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

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↗
PubMed1998

[Clinical evaluation of Azasetron Hydrochloride: a new selective 5-HT3 receptor antagonist--antiemetic profile and plasma concentration in transcatheter arterial chemoembolization using CDDP for unresectable hepatocellular carcinoma].

We performed a clinical evaluation on the antiemetic profile and the plasma concentration of Azasetron Hydrochloride (a new selective 5-HT3 receptor antagonist), in transcatheter arterial chemoembolization using CDDP for unresectable hepatocellular carcinoma. Antiemetic effects were examined in 32 patients in the serotone group (administration of serotone 10 mg + methylprednisolone 125 mg) and in 77 patients of the control group (administration of metoclopramide 20-30 mg + methylprednisolone 500 mg). The response rate and the CR ratio in serotone group was 97% and 66%, respectively. These results were statistically higher than in the control group. Although all patients had chronic liver diseases, no side effects and complications related to administration of serotone were observed. The average area under the concentration (AUC) curve of plasma serotone in five patients with liver cirrhosis was 531 ng.h/ml, which was greater than that of a healthy volunteer. In conclusion, serotone is a new, safe and useful antiemetic drug in TACE therapy for hepatocellular carcinoma.

Aged↗
PubMed1998

[A case report of acute encephalitis with neuro-psychiatric side-effects of acyclovir].

We reported a 5-year-old boy with acute encephalitis due to suspected herpes simplex infection, who developed confusion, agitation and insomnia during intravenous administration of acyclovir. He recovered from these neuro-psychiatric symptoms two days after the cessation of acyclovir. The same symptoms recurred two days after its re-administration and resolved on the next day of the second cessation of the drug. Electroencephalogram (EEG) showed periodic lateralized epileptiform discharges (PLEDs) on hospital day 16, which disappeared on hospital day 27, suggesting that neurotoxicity of acyclovir may induce PLEDs. Although acyclovir is useful for the treatment of herpes simplex and varicella-zoster virus infections, we have to pay attention to its neurotoxicity.

Acute Disease↗
PubMed1997

In situ nitric oxide (NO) measurement by modified electrodes: NO labilized by photolysis of metal nitrosyl complexes.

Described are studies directed at refining quantitative analysis of nitric oxide in solution using electrochemical techniques. The fabrication and behavior of several sensors based on modified carbon-based electrodes are reported. This technique has been used to resolve the vexing problem of determining the stoichiometry of the photochemical decomposition of the known antihypertension agent sodium nitroprusside, Na2[Fe(CN)5NO], as well as of two other metal nitrosyl complexes of biological interest, Roussin's black salt, NH4[Fe4S3(NO)7], and Roussin's red salt, Na2[Fe2S2(NO)4], in aqueous solutions. In this manner it was shown that the molar ratios of nitric oxide produced per starting complex photochemically decomposed were 0.95 +/- 0.03, 5.9 +/- 0.2, and 0.50 +/- 0.02 for Na2[Fe(C-N)5NO], NH4[Fe4S3(NO)7], and Na2[Fe2S2(NO)4], respectively.

Electrochemistry↗
PubMed1997

A novel migration pathway for rat dendritic cells from the blood: hepatic sinusoids-lymph translocation.

The migration pathways for dendritic cells (DC) from the blood are not yet completely resolved. In our previous study, a selective recruitment of DC progenitors from the blood to the liver was suggested. To clarify the role of the hepatic sinusoids in the migration of blood DC, relatively immature DC and mature DC were isolated from hepatic and intestinal lymph, and intravenously transferred to allogeneic hosts. It was then possible to detect small numbers of DC within secondary lymphoid tissues either by immunostaining for donor type major histocompatibility complex class I antigen or, at much higher sensitivity, for bromodeoxyuridine incorporated by proliferating cells (mainly T lymphocytes), which responded to the alloantigen presented by the administered DC. The intravenously injected DC accumulated in the paracortex of regional lymph nodes of the liver via a lymph-borne pathway. Intravenously injected fluorochrome-labeled syngeneic DC behaved similarly. In contrast, very few DC were found in spleen sections and were hardly detectable in other lymph nodes or in other tissues. An in situ cell binding assay revealed a significant and selective binding of DC to Kupffer cells in liver cryosections. It is concluded that rat DC can undergo a blood-lymph translocation via the hepatic sinusoids, but not via the high endothelial venules of lymph nodes. Hence the hepatic sinusoids may act as a biological concentrator of blood DC into the regional hepatic nodes. Kupffer cells may play an important role in this mechanism.

Animals↗
PubMed1997

Vibrio alginolyticus mutants resistant to phenamil, a specific inhibitor of the sodium-driven flagellar motor.

The polar flagella of Vibrio alginolyticus are driven by sodium motive force and those motors are specifically and strongly inhibited by phenamil, an amiloride analog that is thought to interact with a sodium channel of the flagellar motor. To study the sodium ion coupling site, we isolated motility mutants resistant to phenamil and named the phenotype Mpa(r) for motility resistant to phenamil. The motility of the wild-type (Mpa(s)) was inhibited by 50 microM phenamil, whereas Mpa(r) strains were still motile in the presence of 200 microM phenamil. The Ki value for phenamil in the Mpa(r) strain was estimated to be five times larger than that in the Mpa(s) strain. However, the sensitivities to amiloride or benzamil, another amiloride analog, were not distinctly changed in the Mpa(r) strain. The rotation rate of the wild-type Na+-driven motor fluctuates greatly in the presence of phenamil, which can be explained in terms of a relatively slow dissociation rate of phenamil from the motor. We therefore studied the stability of the rotation of the Mpa(r) and Mpa(s) motors by phenamil. The speed fluctuations of the Mpa(r) motors were distinctly reduced relative to the Mpas motors. The steadier rotation of the Mpa(r) motors can be explained by an increase in the phenamil dissociation rate from a sodium channel of the motor, which suggests that a phenamil-specific binding site of the motor is mutated in the Mpa(r) strain.

Amiloride↗