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Biomedical subjects

T Fukushima

Publications and source records attributed to T Fukushima.

At least 145 records · Page 8Linked to original sources
PubMed1999

Negative regulation of myeloid cell proliferation and function by the SH2 domain-containing tyrosine phosphatase-1.

The SH2 domain containing tyrosine phosphatase SHP-1 has been implicated in the regulation of a multiplicity of signaling pathways involved in hemopoietic cell growth, differentiation, and activation. A pivotal contribution of SHP-1 in the modulation of myeloid cell signaling cascades has been revealed by the demonstration that SHP-1 gene mutation is responsible for the overexpansion and inappropriate activation of myelomonocytic populations in motheaten mice. To investigate the role of SHP-1 in regulation of myeloid leukocytes, an HA epitope-tagged dominant negative (interfering) SHP-1 (SHP-1C453S) was expressed in the myelo-monocytic cell line U937 using the pcDNA3 vector. Overexpression of this protein in SHP-1C453S transfectants was demonstrated by Western blot analysis and by detection of decreased specific activity. Growth, proliferation, and IL-3-induced proliferative responses were substantially increased in the SHP-1C453S-overexpressing cells relative to those in control cells. The results of cell cycle analysis also revealed that the proportion of cells overexpressing SHP-1C453S in S phase was greater than that of control cells. The SHP-1C453S-expressing cells also displayed diminished rates of apoptosis as detected by flow cytometric analysis of propidium iodide-stained cells and terminal deoxynucleotidyltransferase-mediated fluorescein-dUTP nick end-labeling assay. While motility and phagocytosis were not affected by SHP-1C453S overexpression, adhesion and the oxidative burst in response to PMA were enhanced in the SHP-1C453S compared with those in the vector alone transfectants. Taken together, these results suggest that SHP-1 exerts an important negative regulatory influence on cell proliferation and activation while promoting spontaneous cell death in myeloid cells.

Animals↗
PubMed1999

Persistence and clinical outcome of hepatitis G virus infection in pediatric bone marrow transplant recipients and children treated for hematological malignancy.

The natural course and the clinical significance of hepatitis G virus (HGV) infection were investigated in 106 pediatric patients who received chemotherapy for hematological malignancy or underwent bone marrow transplantation (BMT) using HGV-RNA and antibodies to the HGV-E2 protein (anti-E2). HGV markers were detected in 21 patients (19.8%; HGV-RNA in 19 and anti-E2 in 2). Longitudinal analysis of these HGV-infected patients showed that 1 had anti-E2 before the initial blood transfusion, 14 had persistent viremia, and 6 became clear of circulating HGV-RNA after completion of therapy, although 5 of the 6 HGV-cleared patients never developed anti-E2. Reactivation of HGV infection during chemotherapy was observed in two anti-E2-positive, HGV-RNA-negative patients; the reappearance of the same HGV strain was confirmed by phylogenetic analysis. Among BMT survivors without other known causes of liver dysfunction, HGV-RNA-positive patients had a higher peak serum alanine amino transferase (ALT) value than negative patients. Contrary to previous reports, immunosuppressed patients can apparently recover from HGV infection without detectable anti-E2 and some patients who supposedly recovered from HGV infection can nonetheless suffer exacerbation when subsequently immunosuppressed.

Adolescent↗
PubMed1999

Changes of plasma L-arginine levels in spontaneously hypertensive rats under induced hypotension.

Nicardipine, a dihydropyridine type calcium channel blocker, was infused at two flow-rates into spontaneously hypertensive (SH) and control normotensive Wistar-Kyoto (WKY) rats (young, 6-week-old and adult, 23-week-old, n = 5) under pentobarbital anesthesia, to cause hypotension. Mean arterial blood pressure and the concentrations of plasma amino acids and norepinephrine (NE) were measured before infusion and at each step of the infusion. The reduction in blood pressure caused by nicardipine induced a decrease in plasma L-arginine concentration in both young and adult SH rats, this effect being larger in adult rats. There was no significant change in plasma levels of L-arginine in age-matched WKY rats. The concentration of other amino acids did not change in both rat strains. On the contrary, there was an increase in plasma NE concentration in both SH and WKY rats after infusion with nicardipine. Plasma L-arginine concentration showed a good inverse correlation with the logarithm of plasma NE concentration in SH and WKY rats and the correlation was expressed as Y = -alpha log(X) + m (Y, plasma L-arginine concentration (nmol/mL); X, plasma NE concentration (pmol/mL); alpha, a slope; and m, an intercept). alpha, 43.0 and 4.35 for 23-week-old SH and WKY rats, respectively, and 17.0 and 4.0 for 6-week-old SH and WKY rats, respectively. The present data together with previous data suggest a direct noradrenergic stimulation of the synthesis of nitric oxide (NO) from L-arginine. The findings also indicate an impairment of the L-arginine metabolism or pools in SH rats compared with WKY rats. The deficiency of L-arginine increases with the age of SH rats and could be related to the development and maintenance of hypertension due to inefficient production of NO.

Animals↗
PubMed1999

Determination of aspartic acid enantiomers in bio-samples by capillary electrophoresis.

Enantiomeric separation and detection of D,L-aspartic acid (Asp) derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) by capillary electrophoresis (CE) using modified cyclodextrins as chiral selectors was studied. Heptakis(2,3, 6-tri-O-methyl)-beta-cyclodextrin(TM-beta-CD) was most effective for enantiomeric separation of NBD-D,L-Asp with optimum conditions of 30 mM TM-beta-CD in 50 mM phosphate buffer (pH 4.0) and the limit of detection (LOD) attained was 100 nM for each enantiomer. The method proposed in the present study was convenient for both D- and L-Asp determination since the other amino compounds migrated differently and D-Asp in bio-samples such as rat pineal gland and foods was determined with a simple sample pretreatment and a short analysis run time.

Animal Feed↗
PubMed1999

Fluorimetric determination of D- and L-lactate derivatized with 4-(N, N-dimethylaminosulfonyl)-7-piperazino-2,1,3-benzoxadiazole (DBD-PZ) by high-performance liquid chromatography.

A highly sensitive method, based on fluorescence derivatization with 4-N,N-dimethylaminosulfonyl-7-piperazino-2,1,3-benzoxadiazol e (DBD-PZ), was developed for the determination of D- and L-lactic acid. High-performance liquid chromatographic separation of the lactic acid derivative was achieved using an octadecylsilica column followed by enantiomeric separation on a phenylcarbamoylated beta-cyclodextrin chiral column. The separation factor for D, L-lactic acid derivatives was 1.30 using MeOH/H(2)O (80/20) as a mobile phase, and the detection limits were approximately 360 and 300 fmol on column for D- and L-lactic acid derivative, respectively. The proposed method was applied to determine D- and L-lactate in a wine and a lactic drink. Both D- and L-lactate could be determined simultaneously, with the precisions ranging from 3.50 to 5.78% for intra-day and 4.28-9.92% for inter-day determinations. The relative recovery was in the range of 91.6-100%.

Calibration↗
PubMed1999

Propensity of ectopic liver to hepatocarcinogenesis: case reports and a review of the literature.

Two patients with ectopic liver are described. In one patient, a small ectopic liver attached to the gastric serosa developed hepatocellular carcinoma (HCC). The preoperative diagnosis was an alpha-fetoprotein (AFP)-producing carcinoma and a malignant ulcer of the stomach. Total gastrectomy and esophago-jejunostomy were performed. The tumor that measured 4 x 2 x 2 cm contained an AFP-producing HCC and normal liver tissue. In another patient who had alcoholic cirrhosis, ectopic liver on the serosa of the gallbladder was found to have the same histological changes as the mother liver. A survey of the literature disclosed more than 20 cases in which HCC developed outside the liver; the liver did not have HCC. By contrast, there was only one report on HCC occurring in the liver in the presence of a noncancerous, relatively large accessory liver lobe. Because ectopic liver does not have a complete vascular and ductal system as a normal liver, it is perhaps functionally handicapped and more prone to hepatocarcinogenesis.

Carcinoma, Hepatocellular↗
PubMed1999

Comparison of hematopoietic activities of human bone marrow and umbilical cord blood CD34 positive and negative cells.

Although the hematopoietic activities of human CD34+ bone marrow (BM) and cord blood (CB) cells have been well characterized, the phenotype of nonobese-diabetic severe combined immunodeficient (NOD/SCID) mice repopulating cells (SRCs) in CB and BM has not yet been fully examined. To address this issue, various hematopoietic activities were compared in terms of total and CD34+ CB and BM cells. Clonal culture of fluorescence-activated cell sorter (FACS) CD34+ CB and BM cells revealed a higher incidence of colony-forming cells with greater proliferation capacity in CB over BM CD34+ cells. CB CD34+ cells also demonstrated higher secondary plating efficiency over BM cells. In addition, we demonstrated that mice transplanted with CB mononuclear cells (MNCs) showed significantly higher levels of chimerism than those transplanted with BM MNCs. However, recipients of FACS-sorted CD34+ CB cells showed significantly lower levels of chimerism than those that received total CB MNCs, suggesting a role of facilitating cells in the CD34- cell population. To further analyze the role of CD34- cells, the NOD/SCID repopulating ability of FACS-sorted CB CD34-c-kit+Lin- and CD34-c-kit-Lin- cells were examined. However, SRCs were not detected in those cells. Taken together, these data suggest that CB is a better source of hematopoietic stem cells and that there are cells in the CD34- fraction that facilitate repopulation of hematopoiesis in the NOD/SCID environment.

Animals↗
PubMed1999

Distal-proximal somatotopy in the human hand somatosensory cortex: a reappraisal.

The distal-proximal representation of the finger and palm in the first somatosensory cortex was reexamined. Somatosensory evoked magnetic fields (SEFs) were measured with a 37-channel first-order axial gradiometer system. Sensory stimulus comprising a 20-ms vibration at a frequency of 200 Hz was delivered to five successive sites in 3-cm increments along the distal-proximal direction over the volar surface of the right index finger and palm. Using a single dipole model, the sources and the signal strengths of the main peak (M50) of the SEFs were estimated. All of the sources were located in the 3b area. There were no statistically significant differences between the locations of dipoles evoked by stimulation of different sites. The results support those of our previous study using a 122-channel whole-head planar gradiometer system that orderly distal-proximal representation of the hand, as described in monkeys, is blurred in the adult human somatosensory cortex.

Adult↗
PubMed1999

A magnetic resonance abnormality correlating with permeability of the blood-brain barrier in a child with chemical meningitis during central nervous system prophylaxis for acute leukemia.

Chemical meningitis developed in a boy with acute lymphoblastic leukemia during central nervous system (CNS) prophylaxis. Cerebrospinal fluid examination showed pleocytosis and a high protein level. There were no malignant cytological findings. Calculated permeability of albumin across the blood-brain barrier (BBB) was more elevated than that of immunoglobulin or alfa2-macroglobulin. Magnetic resonance imaging (MRI) revealed diffuse pachymeningeal enhancement without any intracerebral lesion. Subsequent CNS prophylaxis was postponed. CSF findings and BBB permeability returned to normal, correlating well with the decrease of MRI abnormality.

Albumins↗
PubMed1999

Intracranial hemorrhage in an infant owing to vitamin K deficiency despite prophylaxis.

A 3-month-old male infant with intracranial hemorrhage attributable to a vitamin K deficiency is reported. Vitamin K2 was administered orally at birth and then at 5 days and I month of age. Oral antibiotics were also given 2 days before the onset of bleeding. Although the incidence of intracranial hemorrhage resulting from vitamin K deficiency has decreased since the introduction of vitamin K2 prophylaxis, spontaneous intracranial hemorrhages are still being reported in infants. We suggest that vitamin K prophylaxis is needed especially for breast-fed infants and for those undergoing antibiotic therapy.

Cerebral Hemorrhage↗
PubMed1999

A Japanese family with autosomal dominant growth hormone deficiency.

UNLABELLED: We report a 1-year-old Japanese boy and his father with isolated growth hormone deficiency II. In both cases, a G-->A transition of the first base of the donor splice site of intron 3 of the growth hormone-1 gene was detected. All unaffected family members were homozygous normal. CONCLUSION: This is the fourth reported case of autosomal isolated growth hormone deficiency II with a G-->A transition. The CG dinucleotide at the exon 3-intron 3 junction of the growth hormone-1 gene appears to be a hot spot for point mutations.

Adult↗
PubMed1999

Recombinant vaccinia viruses expressing an immunodominant epitope of HIV-1 envelope protein within an influenza hemagglutinin cassette predominantly prime epitope-specific CD8(+) CTL.

We constructed recombinant vaccinia viruses (RVV) expressing a 15-residue peptide (P18IIIB; RIQRGPGRAFVTIGK) of gp160 envelope protein from a human immunodeficiency virus type-1 (HIV-1) IIIB isolate using an H1 influenza virus hemagglutinin (HA) gene cassette. Immunofluorescent tests with antisera against both H1N1 influenza virus and P18IIIB localized chimeric HA molecules comprising influenza virus HA and P18IIIB peptide intracellularly, but the P18IIIB could not be seen on the outer surfaces of infected cells though weak fluorescence was detected regarding HA molecule. Consistent with these findings, Western blotting confirmed the expression of a polypeptide of about 74-kDa protein representing chimeric HA molecule in the infected cells. These recombinants markedly primed CD8(+) cytotoxic T lymphocytes (CTL) specific for P18IIIB as well as HA protein of the influenza virus, but failed to elicit P18IIIB-specific antibody despite stimulating production of HA-specific antibody. In addition, the P18IIIB-specific CTL could strongly lyse target cells expressing the whole HIV-1 envelope gene of IIIB strain. Thus, the influenza virus chimeric HA cassette vector system used in the present study appeared to be a useful tool for constructing vaccine candidates which will predominantly prime CD8(+) CTL specific for immunodominant determinants of various infectious agents.

Amino Acid Sequence↗
PubMed1999

Hemodynamic patterns of women with chronic hypertension during pregnancy.

OBJECTIVE: The purpose of the study was to evaluate the hemodynamic changes during an initial and subsequent gestation of 15 patients with chronic hypertension. STUDY DESIGN: Data on mean arterial pressure, rapid ejection time, and pulse wave arrival time, recorded at 26 weeks and 37 weeks, were correlated with birth weight and gestational age. Hemodynamic data were acquired with a noninvasive cardiovascular monitor, and blood pressure was recorded with an oscillometric technique. Statistical analyses were performed with the paired Student t test and simple correlation. RESULTS: The birth weights increased in 9 patients and decreased in 6, although more babies were delivered before 37 weeks in the subsequent pregnancy (7 vs 4 patients). No differences were found between the groups of index and repeated pregnancies or among the subgroups whose infant birth weights increased or decreased, except for the pulse wave arrival time at 37 weeks (172 +/- 21 ms vs 143 +/- 29 ms, P <.05). However, strong correlations emerged between the initial pregnancy's rapid ejection time versus the mean arterial pressure at week 37 (r = 0.81, P =.0013) and the repeated pregnancy's rapid ejection time at week 26 versus the gestational age (r = -0.95, P =.00003). CONCLUSION: These observations suggest that rapid ejection time, an empiric indicator of vascular compliance, may have a role in the evaluation and management of hypertension in pregnancy.

Adult↗
PubMed1999

Brain abscess caused by Streptococcus intermedius: two case reports.

BACKGROUND: Although Streptococcus intermedius has been recognized as an important pathogen for abscess formation outside the central nervous System, the Streptococcus milleri group, of which it is a member, has not been recognized as a specific pathogen for brain abscess, often thought to be caused by Streptococcus viridans, which includes other streptococcal species. CASE DESCRIPTION: Two cases of brain abscess in the left frontal lobe caused by S. intermedius, which responded well to antimicrobial treatment combined with needle aspiration, are presented. In the first patient, the predisposing disease was paranasal sinusitis of the frontal and ethmoid sinuses. In the second patient, the source of the pathogen was not detected despite extensive examination. The patients underwent aspiration of pus under ultrasound guidance in the first patient, and via a computed tomography-guided stereotactic procedure in the second patient. They subsequently received appropriate antimicrobial therapy against S. intermedius isolated from the pus culture. Both patients were discharged without any neurological deficits. CONCLUSION: It is important to recognize S. intermedius as a pathogen of brain abscess, and to be aware of its predisposing factors, i.e., mucosal disturbance and liver abscess.

Adolescent↗
PubMed1999

Effect of PSC 833 on the cytotoxicity of idarubicin and idarubicinol in multidrug-resistant K562 cells.

We examined the effect of PSC 833, a non-immunosuppressive cyclosporin analogue, on the cytotoxicity, accumulation and retention of idarubicin (IDA) and its 13-dihydro metabolite, idarubicinol (IDAol). P-glycoprotein (PGP)-overexpressing multidrug-resistant K562/D1-9 cells were used for these studies. PSC 833 had no effect on the cytotoxicity, intracellular accumulation, or retention of IDA and IDAol in the parent K562 cells. However, intracellular accumulation of IDA and IDAol in K562/D1-9 cells after a 60-min incubation was restored by 0.4 microM PSC 833 to 104% and 116%, respectively, of the level in parent K562 cells. The retention of IDA and IDAol in K562/D1-9 cells was also restored by 0.4 microM PSC 833. Consequently, 0.4 microM PSC 833 increased the sensitivity of K562/D1-9 cells to IDA and IDAol. The resistance index (RI) of IDA decreased from 20-fold to 4.0-fold, and the RI of IDAol decreased from 104-fold to 1.5-fold. These results suggest that the combination of IDA and PSC 833 may be effective in reversing PGP-mediated multidrug resistance in leukemia cells.

Antibiotics, Antineoplastic↗
PubMed1999

Effect of dentin primers containing N-methylolacrylamide or N-methylolmethacrylamide on dentin pretreatment.

The effect of experimental dentin primers containing N-methylolacrylamide (MEAA) or N-methylolmethacrylamide (MEMA) on the bonding of three commercial light-cured resin composite systems [Restorative Z 100 (Scotchbond), Palfique Estelite (Macbond) and Photo Clearfil A (Clearfil Photobond)] to etched dentin was investigated. Water solutions of 35% hydroxyethyl methacrylate (HEMA). 50% MEAA or 30% MEMA were used as dentin primers. The dentin etched with 10% phosphoric acid solution was pretreated with dentin primers for 30 s. The resin composite systems were applied in a Teflon tube positioned onto pretreated dentin surfaces. After water immersion for 1 day, the shear bond strengths were measured. The thicknesses of hybrid layers at dentin-resin interfaces treated with 6 mol/l HCl and 1% NaOCl were measured by scanning electron microscopy. The dentin primer pretreatment increased the bond strengths of all resin composite systems. For Macbond and Clearfil Photobond, the bond strengths (14.2-26.5 MPa) with MEAA and MEMA were higher than those (10.5 and 17.8 MPa) with HEMA. All hybrid layer thicknesses were 1-1.5 microns after HCl immersion. The hybrid layers after NaOCl immersion become narrower. The main fracture pattern of specimens exhibiting high bond strengths (more than 14.2 MPa) was dentin cohesive fracture after bond test. For Macbond and Clearfil Photobond, the layers of specimens pretreated with MEAA and MEMA were clearly thicker than those pretreated with HEMA after NaOCl immersion. MEAA and MEMA solutions were more effective in improving the bond strength of Macbond and Clearfil Photobond to etched dentin than was HEMA. Macbond and Clearfil Photobond created good hybrid dentin layers which could resist NaOCl-attack when MEAA and MEMA solutions were used as dentin primers.

Acrylamides↗