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Biomedical subjects

Y Tsukada

Publications and source records attributed to Y Tsukada.

At least 55 records · Page 3Linked to original sources
PubMed1998

In vitro and in vivo selectin-blocking activities of sulfated lipids and sulfated sialyl compounds.

There is accumulating evidence that sulfated lipids, sulfated oligosaccharides and other sulfated compounds are reactive with selectins in a manner that interferes with selectin interactions with their natural ligands. In the report we describe the ability of sulfated lipids (sulfatides and gangliosides) and multimeric forms of sulfated sialic acid to block binding of P- and E-selectin-Ig to neutrophils. The in vivo ability of these compounds to block lung injury in rats following i.v. infusion of purified cobra venom factor (CVF), which induces injury that is L- and P-selectin dependent, was also determined as well as effects on recruitment of neutrophils, as measured by lung myeloperoxidase. There was a significant correlation between the ability of sulfated lipids and sialyl compounds to interfere in vitro with P-selectin-Ig binding to neutrophils and to protect against P-selectin-dependent acute lung injury induced by CVF. The biological effects of these sulfated compounds were also associated with diminished accumulation of neutrophils. The protective effects of these compounds may be linked to their ability to interfere with P-selectin binding to counter-receptors on neutrophils.

Animals↗
PubMed1998

Mammary fibroblast-derived hepatocyte growth factor stimulates growth and morphogenesis of mouse mammary tumor cells in primary culture.

We have recently isolated a mammary growth factor from the conditioned medium of mouse mammary stromal fibroblasts and identified it as a mouse homologue of human HGF (hepatocyte growth factor). To elucidate the role of HGF in mouse mammary tumorigenesis, we produced recombinant mouse HGF and examined its effects on primary cultures of mouse mammary tumor cells in this study. HGF at concentrations above 20 ng/ml maximally stimulated the growth of mammary tumor cells in primary monolayer culture. HGF also stimulated the three-dimensional growth and branching morphogenesis of mammary tumor cells cultured inside collagen gels. A comparison of the growth-stimulating activity of HGF with that of EGF (epidermal growth factor) and KGF (keratinocyte growth factor) revealed that HGF is the most potent growth factor among the three. Immunological studies using an antibody against mouse HGF demonstrated that 74% of the growth-stimulating activity present in the mammary fibroblast-conditioned medium was abolished by the antibody, indicating that HGF is the major growth factor produced by the fibroblasts. These observations thus suggest a role for HGF as a mammary stromal fibroblast-derived factor which stimulates growth and morphogenesis of adjacent mammary tumor cells in vivo.

Animals↗
PubMed1998

Molecular staging of prostate cancer: comparison of nested reverse transcription polymerase chain reaction assay using prostate specific antigen versus prostate specific membrane antigen as primer.

BACKGROUND: We examined the utility for prostate cancer staging of nested reverse transcription polymerase chain reaction (RT-PCR) using either prostate specific antigen (PSA) or prostate specific membrane antigen (PSM) as primer. METHODS: LNCaP cells were used for the in vitro quantification of RT-PCR. RT-PCR was performed on the peripheral blood of 105 control subjects and 63 patients with prostate cancer (32 who eventually underwent radical prostatectomy and 31 with clinical stage D2 cancer). RESULTS: The nested RT-PCR for the PSA and PSM primers was able to detect 1 LNCaP cell per 10(6) leukemia (K562) cells. None of the control subjects was found positive for the presence of prostate cancer cells by nested RT-PCR. In the 32-patient surgery group, the results of nested RT-PCR were significantly correlated with the pathologic stage of the cancer when using PSM primers (P=2.00 x 10(-3) by Kendall's correlation test) but not when using PSA primers (P=0.06). Extraprostatic extension was significantly more closely correlated with positive PSM nested RT-PCR results (P=0.012 by Fisher's exact probability test) than with positive results of PSA, nested RT-PCR, digital rectal examination, CT imaging, level of serum PSA or Gleason score. In the untreated stage D2 patients, the positive result rate of PSM nested RT-PCR was significantly higher than that of PSA nested RT-PCR (P=0.025 by McNemar test). CONCLUSION: Nested RT-PCR using PSM primers appears to predict the prostate cancer stage more accurately than does nested RT-PCR using PSA primers or conventional clinical staging modalities.

Aged↗
PubMed1998

In vivo investigation of glutamate-glutamine metabolism in hyperammonemic monkey brain using 13C-magnetic resonance spectroscopy.

To investigate the metabolism of glutamate and glutamine in living monkey brain, a system of in vivo 13C magnetic resonance spectroscopy (MRS) using 1H-decoupled 13C spectroscopy combined with monitoring temperature changes in the brain by MR phase mapping was developed. Serial 13C-NMR spectra of the amino acids glutamate and glutamine were acquired non-invasively over 4 h from anesthetized monkey brain after the intravenous administration of [1-13C]glucose (0.5-1.0 g/kg). In the acute hyperammonemic state induced by the administration of ammonium acetate (77 mg/kg bolus), it was observed that 13C incorporation into glutamine-4 was clearly accelerated, without changes of 13C incorporation into glutamate-4. During hyperammonemia, it was shown directly by [2-13C]glucose administration that the anaplerotic pathway for the TCA cycle was also augmented, contributing to the formation of glutamine in the astroglia.

Acetates↗
PubMed1998

Action properties of HYI killer toxin from Williopsis saturnus var. saturnus, and antibiotics, aculeacin A and papulacandin B.

The mechanism of the killing and cytocidal effects produced by HYI toxin from Williopsis saturnus var. saturnus, and by the amphiphilic antibiotics aculeacin A and papulacandin B on yeast Saccharomyces bayanus cells was studied. When the yeast cells were treated with these molecules, a discharge of cell materials at the budding position was observed by phase-contrast and scanning electron microscopy. The cytocidal effect of these molecules was most pronounced when the cells were in the logarithmic growth phase. Washing the HYI toxin incubation mixture completely eliminated the killing activity, but in the case of the antibiotics, it only partially reduced the cytocidal activity. Full recovery of the killing activity in the supernatant of the washing solution was observed after HYI toxin incubation, but in the case of the antibiotics, the recovery of cytocidal activity was time-dependent. The activity of membrane beta-1,3-glucan synthase was potently inhibited by HYI toxin, and the concentration of this enzyme in the budding tip was observed. These results suggest that HYI toxin exerts a cytocidal effect on the budding of sensitive yeast cells by inhibiting cell wall synthesis. This mechanism is similar to that of the HM-1 toxin of W. saturnus var. mrakii, and to aculeacin A and papulacandin B, although there are some differences from that of HYI toxin.

Aminoglycosides↗
PubMed1998

Coronary hyperreactivity to adrenergic stimulation and increased nocturnal vagal tone trigger coronary vasospasm.

The relationship between autonomic nervous system activity (ANA) and coronary vasoreactivity during transient myocardial ischemia was determined in patients with vasospastic angina (VA). ANA was measured by power spectral analysis of heart rate variability and humoral factors following intravenous infusion of insulin in 24 patients with VA and 6 control patients. Nine (38%) of the VA patients had significant ST segment depression (STD), and 4 of these patients had symptomatic STD. The frequency of anginal episodes in the 9 patients with VA and STD was significantly greater than that in the 15 VA patients without STD (3.4 +/- 3.1 vs 0.5 +/- 0.8 episodes/week, p < 0.05). The increase in the LF/HF ratio 30 min after insulin injection in patients with STD was significantly greater than that in patients without STD (34 +/- 31% vs 4 +/- 34%, p < 0.05). All of the patients with VA and STD had significant coronary vasospasm in response to the infusion of < or = 20 micrograms of acetylcholine, higher levels of nocturnal parasympathetic activity, and greater norepinephrine production in response to insulin stimulation than the VA patients without STD. These findings suggest that increased vagal tone and hyperreactivity to adrenergic stimulation may trigger vasospasm in patients with VA.

Aged↗
PubMed1998

Purification and properties of a novel sulfatase from Pseudomonas testosteroni that hydrolyzed 3 beta-hydroxy-5-cholenoic acid 3-sulfate.

A novel sulfatase hydrolyzing the sulfate ester bond in 3 beta-hydroxy-5-cholenoic acid 3-sulfate (delta 5-3 beta-sulfate) was purified from Pseudomonas testosteroni ATCC 11996 as the second bile acid sulfatase. The molecular weight was 95,000 and the molecule was composed of a homodimer of a subunit of which the molecular weight was 46,000. This sulfatase hydrolyzed delta 5-3 beta-sulfate to 3 alpha-hydroxy-5-cholenoic acid and sulfuric acid with inversion of beta- to alpha-configuration of the hydroxyl group at the C-3 position of the substrate. The optimum pH and the stable pH of the enzyme were 8.5 and 6.5-9.7, respectively. 3 beta-Sulfate ester bonds of steroids such as isolithocholic acid, pregnenolone, and epiandrosterone, in which the side chain of the steroid ring was shorter than cholesterol, were also hydrolyzed to 3 alpha-hydroxyl compounds corresponding to each steroid compound and sulfuric acid. We tentatively named this novel enzyme bile acid 3 beta-sulfate sulfohydrolase (beta-BSS).

Arylsulfatases↗
PubMed1998

Correlations between interleukin-8, and myeloperoxidase or luminol-dependent chemiluminescence in inflamed mucosa of ulcerative colitis.

Interleukin-8 (IL-8) is a peptide which induces not only chemotaxis of neutrophils but also the release of reactive oxygen metabolites from the neutrophils. There are few reports which clarify the relationships between IL-8 and mucosal infiltration of neutrophils or reactive oxygen metabolites produced by neutrophils in the colonic mucosa of ulcerative colitis (UC). Biopsy specimens of colonic mucosa obtained from 26 patients with active UC and 21 patients with inactive UC were studied in order to clarify the relationships among the inflammation factors in UC. Levels of IL-8 and myeloperoxidase in organ culture media of the biopsy specimens from active UC (measured by ELISA and EIA) were significantly higher than those from inactive UC and controls. Reactive oxygen metabolites of biopsy specimens in active UC (measured by luminol-dependent chemiluminescence) were also markedly increased compared to those in inactive UC and controls. The levels of IL-8 were closely correlated to luminol-dependent chemiluminescence or myeloperoxidase levels. However, the levels of IL-8 and myeloperoxidase did not correlate with the grades of activity on colonoendoscopic findings. These findings suggest that IL-8 may play a role in the pathophysiology of UC but it does not define the endoscopic activity grades of UC.

Adolescent↗
PubMed1998

Serum soluble CD44 levels for monitoring disease states in acute leukemia and myelodysplastic syndromes.

To determine the clinical implications of soluble CD44 (sCD44) levels in hematologic neoplasias, we developed an enzyme-linked immunosorbent assay for sCD44 using two monoclonal antibodies to the standard 90 kDa form, and assessed the serum concentration of sCD44 in normal healthy volunteers, patients with acute leukemia, myelodysplastic syndromes (MDS), and those with chronic myeloid leukemia (CML). Compared to that in normal individuals (n=51; 145. 1 24.6 ng/ml), the serum sCD44 level was significantly elevated in patients with acute myeloid leukemia (AML; n=18; 331.9 99.0 ng/ml, P=0.0001), acute lymphoid leukemia (ALL; n=16; 551.3 427.8 ng/ml, P=0.0001) and CML (n=18; 262.0 97.5 ng/ml, P=0.0001). The sCD44 level was slightly elevated in patients with MDS (n=43; 173.8 54.9 ng/ml, P=0.0071). In patients with acute leukemia, serum sCD44 concentrations decreased significantly in response to treatment and reached nearly normal levels after complete remission (P=0.0005 in AML and P=0.0032 in ALL). The sCD44 levels in patients with MDS increased after they developed acute leukemia, whereas no significant difference in sCD44 levels was observed between the chronic and the blastic phases in patients with CML. Our results indicate that serum sCD44 levels may be a useful marker for monitoring response to treatment and disease progression, especially in acute leukemia.

Acute Disease↗
PubMed1998

Levels of serum glycosaminoglycans in renal failure.

We measured the concentration of serum glycosaminoglycans (GAGs) in patients with glomerulonephritis, renal failure and on hemodialysis using the dye binding method. In glomerulonephritis, concentration of serum GAGs did not increase, and there was no correlation between serum and urinary GAGs. In patients with renal failure and hemodialysis, concentration of serum GAGs was significantly lower than in controls. Concentration of serum GAGs was correlated with concentration of serum albumin, which is an indicator of malnutrition in patients on hemodialysis. One month of hemodialysis did not affect the concentration of serum GAGs in patients with renal failure, but six months of hemodialysis increased the concentration of serum GAGs. These results suggest that matrix production is suppressed in renal failure with malnutrition.

Adult↗
PubMed1997

Bisecting GlcNAc structures act as negative sorting signals for cell surface glycoproteins in forskolin-treated rat hepatoma cells.

The bisecting N-acetylglucosamine residue is formed by UDP-N-acetylglucosamine:beta-D-mannoside-beta-1, 4-N-acetylglucosaminyltransferase III (GnT-III), a key branching enzyme for N-glycans. We found that forskolin, an adenylyl cyclase activator, markedly enhanced GnT-III at the transcriptional level in various hepatoma cells and hepatocytes, resulting in an increase of bisecting GlcNAc residues in various glycoproteins, as judged from the lectin binding to erythroagglutinating phytohemagglutinin (E-PHA). In whole cell lysates, the E-PHA binding was increased, and leukoagglutinating phytohemagglutinin (L-PHA) binding was decreased at 12 h after forskolin treatment, by time, both GnT-III activity and mRNA had reached the maximum levels. In contrast, the binding capacity as to E-PHA, determined by fluorescence-activated cell sorting on the cell surface, was decreased, suggesting that bisecting GlcNAc structures in certain glycoproteins changed the expression levels of glycoproteins and decreased their sorting on the cell surface. Fractionated organelles of M31 cells showed that the binding capacity as to E-PHA was mainly localized in Golgi membranes and lysosomes. This was also supported by a fluorescence microscopy. In order to determine whether or not the bisecting GlcNAc residue acts as a sorting signal for glycoproteins, N-oligosaccharide structures of lysosomal-associated membrane glycoprotein 1 and beta-glucuronidase, gamma-glutamyltranspeptidase, and secretory glycoproteins such as ceruloplasmin and alpha-fetoprotein were measured by E-PHA and L-PHA blotting after immunoprecipitation. The expression levels of lysosomal membrane glycoprotein 1 and gamma-glutamyltranspeptidase on the cell surface were decreased at 12 h after forskolin treatment, indicating that the bisecting GlcNAc structure may act as a negative sorting signal for the cell surface glycoproteins and may alter the characteristics of hepatoma cells. This is the first report on glycoprotein sorting related to a specific structure of oligosaccharides, bisecting GlcNAc.

Acetylglucosamine↗
PubMed1997

Arthrobacter ureafaciens sialidase isoenzymes, L, M1 and M2, cleave fucosyl GM1.

Among bacterial, fungal and viral sialidases, the sialidase from Arthrobacter ureafaciens has the unique property of cleaving sialic acids linked to the internal galactose of gangliotetraose. In this study, we examined the ability to cleave the internal sialic acids of GM1 and fucosyl GM1 of sialidases from several bacterial and fungal origins, including Clostridium perfringens and Vibrio cholerae. We found that A. ureafaciens sialidase could liberate the sialic acid of GM1 at the highest rate, and was the only enzyme which could cleave fucosyl GM1 among the sialidases examined. The affinity-purified sialidase derived from the culture medium of A. ureafaciens was comprised of four isoenzymes with different molecular weights and isoelectric points, the isoenzymes that cleaved fucosyl GM1 being L (88 kDa, pl 5.0), M1 (66 kDa, pl 6.2) and M2 (66 kDa, pl 5.5), but not S (52 kDa, pl 6.2) which showed the highest specific activity toward colominic acid among the four isoenzymes.

Animals↗
PubMed1997

Purification and characterization of N-acetylneuraminate synthase from Escherichia coli K1-M12.

N-Acetylneuraminate (NeuAc) synthase, which catalyzes NeuAc synthesis by condensation of N-acetyl-D-mannosamine (ManNAc) and phosphoenolpyruvate (PEP), was purified from a cell extract of Escherichia coli K1-M12 to electrophoretically homogeneity by serial column chromatographies. The molecular weight of native enzyme was estimated to be 106,000 by gel filtration. After denaturation in sodium dodecyl sulfate, the molecular weight was reduced to 52,000, indicating the existence of 2 identical subunits. The optimum pH was 7.5 and the stable pH range was 7.0 to 10.0. The enzyme was thermostable up to 30 degrees C. No metal ion was required for the enzyme activity. SH-inhibitors such as p-chloromercuribenzoic acid and mercury chloride were potent inhibitors. The K(m) for ManNAc and PEP were 5.6 mM and 0.04 mM, respectively.

Chloromercuribenzoates↗
PubMed1997

Malignant lymphoma involving the penis following malignant pleural mesothelioma.

A 74-year-old man who had been diagnosed with malignant mesothelioma developed malignant lymphoma of B-cell origin involving the penis. He had a history of occupational exposure to asbestos as a construction worker. The association of malignant mesothelioma with lymphoma is rare, and the possibility of asbestos exposure as a common etiology is discussed. The intense stimulation of B lymphocytes and decreased T lymphocyte activity in asbestos-exposed populations may result in development of B-cell malignancies. Though the relationship between asbestos exposure and malignant mesothelioma is firmly established, the relationship between asbestos exposure and lymphoma remains to be investigated.

Aged↗
PubMed1997

Polymorphism of alcohol-metabolizing genes affects drinking behavior and alcoholic liver disease in Japanese men.

Alcohol is known to be mainly metabolized in the liver by alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2), and cytochrome P-450IIEI. The purpose of this study was to clarify the role of polymorphism of these ethanol-metabolizing enzymes in drinking behavior and the progression of alcoholic liver disease among Japanese men. Polymorphism of the ADH2, ALDH2, and P-45IIEI genes were determined by polymerase chain reaction, followed by restriction fragment-length polymorphism analysis in 189 normal Japanese men and 26 male patients with alcoholic liver disease. Drinking behavior was estimated by self-assessment according to DSM-III-R criteria. Facial flushing was reported in 91 subjects heterozygous for ALDH2*1/*2 and in two subjects homozygous for ALDH2*2/*2, but was not found in 96 subjects homozygous for ALDH2*1/*1. In contrast, polymorphism of ADH2 and P-450IIEI did not differ between flushers and nonflushers. Although the flushers only drank a small amount of alcohol (< 20 g of ethanol/day), the nonflushers were divided into a group of moderate drinkers (20 to 80 g/day; n = 54) and a group of heavy drinkers (> 80 g/day; n = 42). A high preponderance of heterozygosity for the ADH2*1/*2 genes (20/42; 60%) and a high frequency of the ADH2*1 allele were found in heavy drinkers, compared with moderate drinkers. However, cytochrome P-45IIEI gene polymorphism was similar among the moderate and heavy drinkers. Not only a high frequency of the ALDH2*1 and ADH2*1 alleles, but also a high frequency of the P-450IIEI c2 allele was found in the patients with alcoholic liver disease. From these results, the drinking behavior of Japanese men is strongly influenced by the ALDH2*1 allele, and the level of alcohol intake is affected by the ADH2*1 allele, but not by cytochrome P-45IIEI. However, progression to alcoholic liver disease among heavy drinkers may be affected by the cytochrome P-450IIEI c2 allele.

Adult↗