Search PubMed⌕ Search

Biomedical subjects

S Kudo

Publications and source records attributed to S Kudo.

At least 181 records · Page 10Linked to original sources
PubMed1995

Tissue-specific transcriptional regulation of human leukosialin (CD43) gene is achieved by DNA methylation.

The expression of human leukosialin (CD43), a major sialoglycoprotein on the surface of hematopoietic cells, is regulated in cell lineage-specific as well as differentiation stage-specific manners. We have shown previously that transcription from the TATA-less promoter is mediated by the transcription factor Sp1, which binds to repeats of a GGGTGG motif in the 5'-flanking sequence. This regulatory region is ubiquitously functional in mammalian cells, providing a high transcriptional potential. No cis-acting element responsible for the specificity of this gene expression was revealed by extensive studies using transient as well as stable expression systems. Here, we demonstrate that DNA methylation plays a key role in leukosialin gene expression. Southern blot analysis of genomic DNAs from various human cell lines with methylation-sensitive and -insensitive restriction enzymes showed a tight correlation between gene activity and demethylation state of the 5'-region of the leukosialin gene. Consistent results were obtained from the same analysis of genomic DNAs from various human tissues. In addition, in vitro DNA methylation of the 5'-region drastically reduced transcriptional activity in a transient expression system. These results indicate that DNA methylation around the 5'-region of the leukosialin gene is required to shut off a high level of transcription. Thus, the tissue-specific expression of the leukosialin gene is constitutively achieved by alteration of DNA methylation.

Antigens, CD↗
PubMed1995

Characteristics of cerebrospinal fluid circulation in infants as detected with MR velocity imaging.

Analysis of cerebrospinal fluid (CSF) flow and motion at the craniospinal junction was conducted by magnetic resonance velocity imaging with phase encoding followed by motion velocity integration. Thirteen normal subjects classified into two groups were studied: an infant group with open sutures and fontanel, and a noninfant group with closed sutures and fontanel. Predominance in CSF to-and-fro motion was recognized in the ventral subarachnoid space, and a maximum caudad motion velocity of 7.5 +/- 2.4 mm/s was recorded in the infant group and one of 14.9 +/- 6.2 mm/s in the noninfant group. The average bulk flow velocity in all cases was 86.7 +/- 81.6 (means +/- SD) mm/min. The difference in flow velocity between the infant group (19.7 +/- 28.2 mm/min) and the noninfant group (116.5 +/- 80 mm/min) suggested that the CSF circulation around the cervical spine may vary at different ages.

Adolescent↗
PubMed1995

Binding of bacterial toxins to glycoproteins in the envelopes of rainbow trout eggs.

The ability of the vitelline and fertilization envelopes of rainbow trout eggs to trap toxins was investigated using cholera enterotoxin B and staphylococcal enterotoxin B in cytochemical or immunocytochemical experiments. Extracts from both envelopes were investigated by immunoblot analysis to identify toxin-binding proteins after SDS-PAGE. Binding studies of cholera enterotoxin B to vitelline envelopes and fertilization envelopes revealed a greater reactive intensity in the former. Treatment with neuraminidase enhanced the reactive intensity (or deposit) in the vitelline envelope and fertilization envelope outermost layers, with more conspicuous reactivity in the former. Cytochemical experiments showed that exogenous ganglioside GM1 considerably enhanced cholera enterotoxin B binding to vitelline and fertilization envelopes. This enhancement was shown by an intense reactivity following the occurrence of new binding sites on the vitelline envelope inner surface and the inner wall of the zona radiata, a simultaneous extreme reduction in the reactivity of the vitelline envelope outermost layer, and a striking increase in reactive products in the fertilization envelope outermost layer. The surface region of the vitelline or fertilization envelope outermost layer was the binding site for staphylococcal enterotoxin B, and neuraminidase treatment caused a considerable reduction of reactive products in these areas. Immunoblot analysis of cholera enterotoxin B- or staphylococcal enterotoxin B-binding substances in extracts from the vitelline envelopes or fertilization envelopes demonstrated that the great majority of the binding substances are glycoproteins. The present results suggest that glycoproteins constituting the vitelline envelope or fertilization envelope may contribute to the protection of the egg itself or the embryo by trapping noxious toxins.

Animals↗
PubMed1995

p53 immunoreactive stain and early colorectal adenocarcinomas.

565 cases of early colorectal adenocarcinomas were used in this study to examine mechanisms of carcinogenesis. Specimens were paraffin embedded and histological sections were stained with haematoxylin-eosin and p53. Macroscopically, early colorectal adenocarcinomas could be classified into two types: protruding and depressed. The former were composed of branching glands, while the latter were composed of straight glands which opened to the surface. The p53 positive ratio was similar for protruding tumours but was higher in depressed submucosal invasive adenocarcinomas than in depressed intramucosal adenocarcinomas. These results raise the possibility of at least two pathways for colorectal carcinogenesis, adenoma-carcinoma lesions and de novo carcinoma lesions.

Adenocarcinoma↗
PubMed1995

Simultaneous measurement of bacterial flagellar rotation rate and swimming speed.

Swimming speeds and flagellar rotation rates of individual free-swimming Vibrio alginolyticus cells were measured simultaneously by laser dark-field microscopy at 25, 30, and 35 degrees C. A roughly linear relation between swimming speed and flagellar rotation rate was observed. The ratio of swimming speed to flagellar rotation rate was 0.113 microns, which indicated that a cell progressed by 7% of pitch of flagellar helix during one flagellar rotation. At each temperature, however, swimming speed had a tendency to saturate at high flagellar rotation rate. That is, the cell with a faster-rotating flagellum did not always swim faster. To analyze the bacterial motion, we proposed a model in which the torque characteristics of the flagellar motor were considered. The model could be analytically solved, and it qualitatively explained the experimental results. The discrepancy between the experimental and the calculated ratios of swimming speed to flagellar rotation rate was about 20%. The apparent saturation in swimming speed was considered to be caused by shorter flagella that rotated faster but produced less propelling force.

Biophysical Phenomena↗
PubMed1995

Antitumoral efficacy and pharmacokinetic properties of pirarubicin upon hepatic intra-arterial injection in the rabbit V x 2 tumour model.

To improve the efficiency of hepatic intra-arterial (h.i.a.) chemotherapy, we selected pirarubicin (THP) because it shows good properties for h.i.a. chemotherapy, such as fast and efficient cellular uptake, and used it for h.i.a. chemotherapy in rabbits with V x 2 tumour implanted in the liver. The anti-tumour effect of THP upon h.i.a. administration was compared with that upon intravenous (i.v.) injection and also with the anti-tumour activity of epirubicin (EPI) upon h.i.a. injection using optimal and maximal tolerated doses of each drug. When tumour growth rates and morphometric examinations were evaluated, it was found that THP and EPI were effective against V x 2 tumour when injected via the h.i.a. route. The activity of THP was stronger than that of EPI. As regards h.i.a. injection-related complication, plasma transaminase levels were temporarily elevated. To demonstrate higher anti-tumour activity and other advantages of h.i.a. injection of THP, plasma and tumour drug concentrations were determined by high-performance liquid chromatography after THP or EPI was administered at an equal dose to the rabbit V x 2 model. Hepatic intra-arterial injection of THP accomplished a selective and higher uptake into the tumour and lower effusion into the plasma than i.v. injection of THP or h.i.a. injection of EPL. Our findings indicate that THP is the better candidate of the two drugs tested for the h.i.a. chemotherapy because of its greater anti-tumour activity and the lower systemic drug exposure achieved upon h.i.a. injection.

Animals↗
PubMed1995

Moyamoya disease in three siblings--follow-up study with magnetic resonance angiography (MRA).

Three siblings with moyamoya disease including identical twins are reported. Although the younger of identical twins had no neurological problems, CT and MRI detected cerebral infarctions and cerebral angiography showed the typical features of moyamoya disease. All three cases underwent encephalo-duro-arterio-synangiosis (EDAS), and serial magnetic resonance angiography (MRA) showed that the distal portions of the middle cerebral artery (MCA) were well perfused through surgically created anastomoses. There were no findings of disease progression. MRA might play an important role in follow-up studies of moyamoya disease.

Brain↗
PubMed1995

Genomic organization of core 2 and I branching beta-1,6-N-acetylglucosaminyltransferases. Implication for evolution of the beta-1,6-N-acetylglucosaminyltransferase gene family.

Two human beta-1,6-N-acetylglucosaminyltransferases forming the core 2 O-glycan branch, C2GnT and the I antigen, IGnT, are homologous to each other in three regions of the catalytic domain (A, B, C) and their genes reside at the same locus, chromosome 9, band q21 (Bierhuizen,M.F.A., Mattei, M.-G. and Fukuda,M., Genes Dev., 7, 468-478, 1993). In order to investigate how these two enzymes are related at the genomic level, and how this gene family evolved, we have elucidated their genomic structures. It was found that C2GnT is coded by two exons, of which the second exon encodes the whole translation product. In contrast, the complete coding sequence for IGnT is divided over three exons. Importantly, the highly homologous region B is encoded entirely by exon 2 in the C2GnT gene, while the same region is split between exons 1 and 2 in the IGnT gene. The other highly homologous regions, A and C, are also encoded by exon 2 in the C2GnT gene, while they are encoded by exon 1 and exon 3, respectively, in the IGnT gene. These results strongly suggest that the common ancestral gene was first duplicated and then each duplicated gene evolved into the C2GnT or IGnT gene by intron insertion and divergence following the duplication. The sequences upstream from the transcription initiation sites of the C2GnT and IGnT genes have promoter activity and contain TATA-like sequences.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

Urinary Phenylglyoxylic Acid Excretion after Exposure to Ethylbenzene among Solvent-exposed Chinese Workers.

Factory surveys were conducted in the second half of work weeks on 360 solvent workers (202 men and 158 women) and 281 controls in China. Monitoring personal exposures showed that ethylbenzene exposure was low (geometric mean 1.8 ppm) and was accompanied by coexposure to toluene (1.5 ppm) and three xylene isomers (6.7 ppm). Urine samples collected at the end of the eight-hour shift were analyzed for phenylglyoxylic and mandelic acids by high-pressure liquid chromatography at 257 nm. Despite the low level of the exposures, a significant correlation was observed between ethylbenzene exposure and urinary phenylglyoxylic acid, with high (0.6-0.7) correlation coefficients, suggesting that urinary phenylglyoxylic acid is a good marker of occupational exposure to ethylbenzene. Mandelic acid also correlated with ethylbenzene exposure, but with much smaller coefficients (0.2), possibly because the method employed was more sensitive to phenylglyoxylic acid than to mandelic acid.

Journal Article↗
PubMed1995

Upper-extremity Musculoskeletal Disorders in Keyboard Operators in Brazil: A Cross-sectional Study.

This study sought to determine the prevalence of upper-extremity musculoskeletal disorders (UEMSDs) among keyboard operators in Sao Paulo, Brazil, and to compare this prevalence with that among other office workers. One hundred and thirty keyboard operators (mean age 33 years, 60 male/70 female) and 138 office workers (mean age 35 years, 82 male/56 female) from two computing centers were interviewed by a research assistant using a standardized questionnaire. Symptomatic subjects, defined as those who reported upper extremity pain or lost work time due to pain in the preceding 12 months, were examined by a rheumatologist. Mean (SD) lengths of employment were 9 (6) years for keyboard operators and 8 (6) years for office workers. Upper-extremity pain during the preceding seven days was reported by 66 keyboard operators (51%) and by 18 office workers (13%) (p < 0.0001); during the preceding 12 months, by 90 keyboard operators (69%) and by 26 office workers (19%) (p < 0.0001). UEMSDs were diagnosed following physical examination in 50 keyboard operators and in 12 office workers (9%) (p < 0.0001). Tenosynovitis was the most common disorder diagnosed among the keyboard operators (n = 23). Among the keyboard operators the prevalence of UEMSDs was significantly lower for males (p = 0.017, OR = 0.38, 95%CI = 0.17-0.86). The presence of a diagnosed UEMSD was significantly associated with duration of employment (p = 0.005) and lack of or insufficient rest breaks (p = 0.012). Keyboard operators had significantly more UEMSDs than did office workers. Strategies aimed at the reduction of repetitive strain injuries among keyboard operators, such as the provision of adequate work breaks, should be evaluated.

Journal Article↗
PubMed1995

[Effect of anticancer drugs on invasive capacity of human small-cell lung cancer cells in vitro].

The effect of anticancer drugs on invasive capacity of Lu 135 human small-cell lung cancer cells was studied in vitro. the invasive capacity decreased in a dose-dependent manner when tumor cells were treated with the anticancer drugs cisplatin and etopside. The inhibition of tumor cell invasion was almost parallel with the inhibition of tumor cell growth. The anticancer drugs also suppressed tumor cell migration and the activity of the matrix-degrading protease, type IV collagenase, activity. But they did not suppress adhesion to basement membrane protein such as laminin, fibronectin, or type IV collagen. Because tumor cells express adhesion molecules on the cell surface, the effect of the anticancer drugs on the expression of one such molecule, integrin, was also studied. Lu 135 cells expressed alpha 4/beta 1 integrin on the cell surface, and the pattern of integrin expression did not change with exposure with the anticancer drugs. These data suggest that the anticancer drugs inhibit the invasive capacity by suppression of migration and type IV collagenase activity of tumor cells, and that they do not modulate adhesion to the extracellular matrix or cell surface adhesion molecules such as integrin. Furthermore, these findings indicate that anticancer drugs may be useful for anti-metastatic therapy in patients with small-cell lung cancer.

Antineoplastic Agents↗
PubMed1995

Pharmacokinetics of human activated protein C. 1st communication: plasma concentration and excretion of a lyophilized purified human activated protein C after intravenous administration in the mouse and the rabbit.

Pharmacokinetic studies of human activated protein C (CAS 42617-41-4, APC) were investigated in mice and rabbits with 125I-labeled compound. Plasma levels of APC were determined by three different assays: total radioactivity, APC antigenicity determined by sandwich enzyme-linked immunosorbent assay (ELISA), and the amidolytic activity which was performed by immunologically captured APC. APC concentration obtained from these assays were shown to be correlated well at early times post-dose. After intravenous administration, total radioactivity in the plasma declined tri-exponentially, but antigenicity and amidolytic activity in the plasma declined biexponentially. Plasma AUC increased proportionally with the dose, and the total body clearance and t1/2 did not change significantly. In addition, no significant difference was observed between the pharmacokinetics in male and female mice. In rabbit study, the profiles of times vs APC concentration in the plasma was similar to those in mice after single bolus injection. The plasma concentrations of APC during and after infusion in rabbits were also determined. APC concentration increased during infusion and reached almost steady state at the end of infusion. The profiles of the APC concentration in benzamidine citrate plasma corresponded to the simulated curves which were characterized by the parameters obtained from the single bolus experiment. Plasma disposition profiles of the protein were studied with high performance gel chromatography method. The radioactivity in the unchanged APC was observed at 15 min after administration. At 1 h, most of the radioactivity was observed in larger molecule fraction than the intact APC. These results corresponded to the decrease of amidolytic activity in the plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Pharmacokinetics of human activated protein C. 2nd communication: tissue distribution study of a lyophilized purified human activated protein C after single or repeated intravenous administration in male mice and placental transfer and milk passage study after intravenous administration in pregnant and lactating mice.

Tissue distribution studies of human activated protein C (CAS 42617-41-4, APC) were performed in mice after single or repeated administration, and placental transfer and milk passage study were investigated. At 15 min after a single intravenous administration of 125I-APC, radioactivity was mainly distributed to the blood and blood rich organ, such as liver, and then rapidly eliminated. The radioactivity distributed to tissues was almost negligible at 24 h after administration except for the thyroid. The qualitative study of the distribution of radioactivity to tissues by whole body autoradiography demonstrated the correspondence to the result of the quantitative assay of distribution of radioactivity after single administration of 125I-APC. The influence of repeated administration of APC on its pharmacokinetic disposition was studied by administering 125I-APC once a day to mice for 14 days. Though plasma radioactivity at 15 min in mice during repeated administration of 125I-APC was almost similar to that at 15 min after a single administration, the radioactivity at 24 h after administration was 2 times higher than that after a single administration. The profile of plasma radioactivity during and after repeated administration corresponded to the simulation curve which was described with the pharmacokinetic parameters obtained previously after the single administration. Distribution profile after repeated administration at 15 min after the 4th, 7th, 10th and 14th administration was almost similar to that at 15 min after a single administration except for the thyroid and spleen. In the thyroid, the radioactivity was 500 times higher than that after a single administration, and HPLC analysis demonstrated that the radioactivity was attributed to thyroglobulin. As to the spleen, the radioactivity was about 52% of that after a single administration. During the repeated administration, the spleen became larger than that after a single administration and the final weight was 2 times heavier than that of the non-treated animal. The decrease in radioactivity of the spleen during repeated administration was attributed to the hypertrophy of the organ. Placental transfer of 125I-APC was studied with pregnant mice quantitatively and qualitatively. Radioactivity distributed in fetuses was low at every point examined, and the result corresponded to the autoradiography. During lactation, radioactivity transferred to milk and milk to plasma ratio reached 5.7 after intravenous administration of 125I-APC. HPLC analysis of the milk radioactivity demonstrated that most of the radioactivity was present in the macromolecules produced by the lactating mother.

Animals↗
PubMed1995

[An overview of prognostic factor in lung cancer].

The current treatment results for lung cancer clearly call for improved therapy and also for careful selection of patients for the treatment options from which they are most likely to benefit. A detail knowledge of prognostic factor is important for achieving these goals. By the stratification of the important prognostic factors, the clinical study can be assessed properly. In this report, prognostic factors that established hitherto, clinicopathological factors, molecular biological factors are reviewed.

Biomarkers, Tumor↗
PubMed1995

[MR imaging of colonic cancer with retrograde administration of contrast material containing ferric ammonium citrate].

MR imaging was performed with the retrograde administration of ferro-magnetic contrast material and air in 10 patients with rectosigmoid colon cancer. The border of the lesions was well demonstrated in spin echo images, and MR imaging yielded additional diagnostic information to that provided by barium enemas and CT scans in all cases. In conclusion, this type of contrast material seemed promising in the MRI diagnosis of rectal lesions.

Administration, Rectal↗
PubMed1995

[Inositol].

Explore the source record for details and available documents.

Diabetes Mellitus↗