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Biomedical subjects

A Manabe

Publications and source records attributed to A Manabe.

At least 55 records · Page 3Linked to original sources
PubMed1999

Hyperdiploid acute lymphoblastic leukemia with 51 to 65 chromosomes: a distinct biological entity with a marked propensity to undergo apoptosis.

To determine the cellular basis for the excellent clinical outcome of hyperdiploid acute lymphoblastic leukemia (ALL), defined by a modal chromosome number of 51 to 65, we assessed the growth potential of leukemic cells from 129 children with newly diagnosed ALL. Flow cytometric analysis was used to compare leukemic cell recoveries at the beginning and at the end of 7-day cultures on allogeneic bone marrow-derived stromal layers. The median percentage of cell recovery after culture was 91% (range, <1% to 550%). Among the 25 hyperdiploid cases, only two had cell recoveries above the median value, compared with 63 of 104 cases with different ploidies (P <.001); 21 had recoveries within the first quartile, in contrast to only 12 of the 104 other cases. Cell recoveries in the 16 cases with duplications of chromosomes 4 and 10, a feature previously associated with a superior outcome, were all within the first quartile. Flow cytometric studies indicated that rapid induction of apoptosis was the underlying cause of low cell recoveries in cases with hyperdiploidy. The demise of hyperdiploid cells on stroma was not due to failure to adhere with stromal elements (as shown by electron microscopy) or to deficiencies of interleukin-1 (IL-1), IL-2, IL-3, IL-4, IL-6, IL-7, IL-11, stem-cell factor, interferon- (IFN-), tumor necrosis factor- (TNF-), or to combinations of these cytokines. Inactivation of IL-4, IFN- and TNF-, which if secreted by stromal layers could be toxic to ALL cells, failed to improve the survival of hyperdiploid blasts. We conclude that leukemic cells bearing 51 to 65 chromosomes have a marked propensity to undergo apoptosis. The stringent survival requirements of these cells, together with their potentially higher sensitivity to antileukemic drugs, may well account for the high cure rates achieved in patients with this form of ALL.

Adolescent↗
PubMed1999

Three-dimensional ultrasonographic evaluation of ovarian tumours: a preliminary study.

Our objective was to determine the accuracy of three dimensional (3D) ultrasonography in the differentiation of ovarian tumours. Women (n = 20) with ovarian tumours (13 benign and seven malignant) were first examined using two-dimensional (2D) ultrasonography and were then evaluated with three-dimensional (3D) ultrasonography. All patients underwent surgery within 7 days of 2D and 3D ultrasonographic evaluations, and a histopathological diagnosis was made. A 2D ultrasonographic diagnosis of malignancy was done using an established scoring system. Diagnostic criteria for ovarian malignancy by 3D ultrasonography were: irregular thick septa, irregular papillary projection, mostly solid tumour, high echogenicity, and irregular inner wall. Compared with 2D ultrasound, 3D ultrasound had a significantly higher specificity (P < 0.005) and accuracy (P < 0.01), and a significantly lower false positive rate (P < 0.005). Our results suggest that 3D ultrasonography might be a better means of differentiating between malignant and benign ovarian tumours. However, in view of the small number of ovarian tumours, these observations must be considered preliminary.

Adult↗
PubMed1999

Nitric oxide synthesis is increased after dehydroepiandrosterone sulphate administration in term human pregnancy.

The purpose of this study was to evaluate the role of nitric oxide in the vasodilative effect of dehydroepiandrosterone sulphate (DHEA-S) in term pregnant women. Circulating nitrite, nitrate and oestradiol concentrations were measured on 10 normal full-term pregnant women before (-30 min) and after (10, 30, 60, 90 and 120 min) administration of a 200 mg i.v. dose of DHEA-S dissolved in 20 ml of 5% dextrose (DHEA-S group). Ten normal full-term pregnant women received 20 ml of 5% dextrose as controls (control group). Maternal blood pressure and heart rate were also recorded. The median oestradiol concentration increased significantly after the infusion in DHEA-S group (P < 0.001), whereas there was no significant change in plasma oestradiol in the control group. In the DHEA-S group, plasma circulating nitrate and nitrite increased significantly at 10 and 30 min after DHEA-S administration respectively (P < 0.05). In the control group, there was no change in plasma nitric oxide (NO) metabolites. No change was found in heart rate or mean arterial blood pressure in the control or DHEA-S groups. These results suggest there may be a link between increased NO and increased oestrogen after DHEA-S injection but their peak values did not coincide. Both may be associated with vasodilation in term pregnant women.

Blood Pressure↗
PubMed1999

Detection of small-for-gestational-age infants with poor perinatal outcomes using individualized growth assessment.

OBJECTIVE: Our objective was to evaluate individualized growth assessment using the Rossavik growth model for detection of small-for-gestational-age (SGA) infants with a poor perinatal outcome. METHODS: Rossavik growth models derived from second-trimester ultrasound measurements were used to predict birth characteristics of 47 singleton SGA infants. Individual fetal growth curve standards for head and abdominal circumference, and weight were determined from the data of two scans obtained before 25 weeks' menstrual age and separated by an interval of at least 5 weeks. Comparisons between actual and predicted birth characteristics were expressed by the Growth Potential Realization Index (GPRI) and Neonatal Growth Assessment Score (NGAS). The proportions of perinatal outcomes [mechanical delivery, low Apgar score, abnormal fetal heart rate (FHR) patterns, neonatal acidosis, meconium staining of amniotic fluid, neonatal intensive care unit (NICU) admission and maternal complications] were compared between SGA infants with normal NGAS and those with abnormal NGAS. RESULTS: Of the 47 fetuses studied, 27 had normal growth outcomes at birth and 20 showed evidence of intrauterine growth restriction, based on NGAS. There were significant increases in mechanical deliveries, abnormal FHR patterns and meconium staining of amniotic fluid in cases of growth-restricted neonates, determined using the NGAS classification, when compared with events related to normally grown infants. However, there were no significant differences in low Apgar score, neonatal acidosis, NICU admission and maternal complications between the 2 groups. CONCLUSION: Individualized growth assessment should be useful for detection of SGA infants with poor perinatal outcomes.

Abdomen↗
PubMed1999

Effect of functional monomer in commercial dentin bonding agents use of an experimental dentin bonding system.

The objective of the present study was to understand the role of the functional monomers in dentin bonding agents of an experimental dentin bonding system by measuring the wall-to-wall contraction gap and tensile bond strength measurement. The efficacy of three commercial dentin bonding agents after using EDTA for conditioning and GM for priming was evaluated by measuring the contraction gap of the resin composite in a cylindrical dentin cavity, and by measuring the tensile bond strength of the composite to a flat dentin surface. The effect of the functional monomers was demonstrated by the contraction gap measurement alone. The value of the contraction gap was significantly different between the commercial dentin bonding agents and these agents without functional monomers (p < 0.05). It was concluded that the functional monomers were essential to obtaining the marginal integrity of the resin composite in the dentin cavities.

Acrylic Resins↗
PubMed1998

Stimulation of mouse and human primitive hematopoiesis by murine embryonic aorta-gonad-mesonephros-derived stromal cell lines.

We report here on a novel stromal cell line, AGM-S3, derived from the aorta-gonad-mesonephros (AGM) region of a 10.5 days postcoitum (dpc) mouse embryo. The AGM-S3 cells promoted production of hematopoietic progenitors and day-12 spleen colony-forming cells from Lin-c-Kit+Sca-1(+) murine primitive hematopoietic cells. They also supported for 6 weeks generation of human multipotential progenitors from cord blood CD34(+)CD38(-) primitive hematopoietic cells. Human long-term repopulating hematopoietic stem cells (LTR-HSC) with the potential to reconstitute hematopoiesis in NOD/SCID mice were maintained on AGM-S3 cells for at least 4 weeks. Flow cytometric analysis showed that CD13, vascular cellular adhesion molecule-1, and Sca-1 were expressed on AGM-S3 cells. Because stem cell factor, interleukin-6 (IL-6), and oncostatin M, but not IL-3, IL-11, leukemia- inhibitory factor, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, thrombopoietin, and Flk2 ligand were detected in reverse transcription-polymerase chain reaction analysis of AGM-S3 cells, the cells seem to express species-cross reactive molecule(s) other than the cytokines examined and which act on primitive hematopoietic progenitor/stem cells. This cell line is expected to elucidate molecular mechanisms regulating early hematopoiesis and pave the way for developing strategies for expansion of human transplantable HSC.

ADP-ribosyl Cyclase↗
PubMed1998

Characterization of leukemic cells in CD2/CD19 double positive acute lymphoblastic leukemia.

In the diagnosis of leukemia, CD2 which is a T-cell associated marker and CD19 which is a B-cell associated marker are widely used to determine the lineage of leukemic cells. It is known that the cells of acute lymphoblastic leukemia (ALL) express both CD2 and CD19 in some cases. The origins of these cells are generally thought to be a common precursor for T- and B-lymphocytes. However, cytoplasmic staining of CD3 which is a more specific marker for T-lineage and cytoplasmic staining of mb-1 (CD79a) which is more specific for B-lineage were not performed in previous reports and the determination of the cell lineages of these cells was unclear. We had two cases of ALL whose blasts were CD2/CD19 double positive. The first case was assessed as B-lineage because the cells expressed cytoplasmic CD79a and lacked cytoplasmic CD3. The immunoglobulin (Ig) heavy chain gene was rearranged. The other cell surface markers including CD22 and HLA-DR also suggested that these cells were B-lineage. The CD2 expression may be a coincidence and should not be taken as a T-cell marker in this case. It was difficult to determine the lineage in the second case because both cytoplasmic CD79a and cytoplasmic CD3 were expressed and neither TCR beta chain nor Ig heavy chain genes were rearranged. The other surface markers were not useful to determine the lineage. We concluded that this case was really an unclassified ALL. Accordingly, cytoplasmic staining of CD3 and CD79a should be carried out in the diagnosis of leukemia when it is difficult to determine the cell lineage.

Adolescent↗
PubMed1998

The adverse effect of commercial dentine-bonding systems on the skin of guinea pigs.

It was widely known that 2-hydroxyethyl methacrylate (2-HEMA) can cause contact dermatitis. Commercially available dentine primers and dentine bonding agents that contain 2-HEMA are widely used. The purpose of this study was to investigate the cumulative irritation and delayed hypersensitivity caused by commercial dentine bonding systems when applied to the skin of guinea pigs. We have concluded that almost no dentine bonding systems cause cumulative irritation, but some commercially available dentine bonding systems may produce delayed hypersensitivity.

Animals↗
PubMed1998

The alpha and eta isoforms of protein kinase C stimulate transcription of human involucrin gene.

Involucrin is one of the precursor proteins of the cornified cell envelope that is formed beneath the cell membrane during terminal differentiation of keratinocytes. 12-O-tetradecanoylphorbol-13-acetate (TPA), which is a potent protein kinase C (PKC) activator, induces terminal differentiation of keratinocytes. We previously demonstrated that involucrin promoter activity is stimulated by TPA in cultured fetal rat skin keratinocytes. PKC is a large family of proteins and keratinocytes containing five PKC isozymes: alpha, delta, epsilon, eta, and zeta. In order to determine the role of the PKC isozyme(s) on involucrin gene expression, we constructed the chloramphenicol acetyl transferase (CAT)-involucrin promoter expression vector by connecting the 5'-upstream region of the human involucrin gene containing the untranslated first exon to the CAT reporter gene. The CAT-involucrin promoter expression vector was transfected with various PKC isozyme expression vectors into SV40-transformed human keratinocytes (SVHK cells). Transfection of the CAT-involucrin promoter expression vector with PKC-alpha or PKC-eta expression vectors resulted in a significant increase in the TPA-dependent involucrin promoter activity. The PKC inhibitor, 1-(5-isoquinoline-sulfonyl)-2-methyl piperazine dihydrochloride, inhibited the promoter activity stimulated by TPA. Transfection of PKC-delta, -epsilon, and -zeta had no effect on the involucrin-promoter activity. Although the promoter activity was stimulated by transfection of PKC-gamma, TPA did not enhance the promoter activity in the PKC-gamma-transfected SVHK cells. Previously we showed three AP-1 binding sites (AP1-1, -2, and -3) on the involucrin promoter region. Both the basal and the TPA-stimulated involucrin promoter activities were suppressed by deleting the AP1-1 site (-119 to -113) that is the most proximal to the transcription start site. The deletion of AP1-2 (-297 to -303) or AP1-3 (-447 to -453) did not affect the involucrin promoter activity. Gel retardation analyses disclosed that TPA stimulated the specific DNA binding of the nuclear protein(s) of control, PKC-alpha, or PKC-eta-transfected SVHK cells, but not of PKC-gamma-transfected cells. Addition of anti-c-Jun and anti-c-Fos antibodies decreased the specific protein-DNA complex band with a concomitant appearance of supershifted bands. These results indicate that PKC, specifically PKC-alpha and PKC-eta, mediates the TPA-dependent activation of involucrin gene expression of SVHK cells. PKC-gamma, which is not present in keratinocytes, also induces involucrin gene expression in a TPA-independent manner, when introduced into SVHK cells.

Base Sequence↗
PubMed1998

Decreased maternal circulating hepatocyte growth factor (HGF) concentrations in pregnancies with small for gestational age infants.

Our purpose was to evaluate whether maternal and fetal hepatocyte growth factor (HGF) concentrations in pregnancies with small for gestational age (SGA) infants are different from those in pregnancies with appropriate for gestational age (AGA) infants. Maternal and fetal circulating HGF concentrations were compared between 55 pregnancies with AGA infants and 16 pregnancies with SGA infants at birth. HGF concentrations were measured from maternal and cord venous blood samples using an enzyme-linked immunosorbent assay. Umbilical artery blood pH and oxidative pressure (PO2) were also measured. Maternal circulating HGF concentrations (0.60+/-0.35 ng/ml) in pregnancies with SGA infants were significantly lower than those (0.91+/-0.44 ng/ml) in pregnancies with AGA infants (P = 0.012). There were no significant differences in fetal circulating HGF concentrations between both groups. No significant differences in umbilical artery blood pH and PO2 were found between both groups. These results suggest that the maternal serum circulating HGF concentration has a significant role in fetal growth during pregnancy.

Adult↗
PubMed1998

Three-dimensional intrauterine sonography in the early first-trimester of human pregnancy: preliminary study.

Our purpose was to visualize normal embryonal surface anatomic structures using three-dimensional (3D) intrauterine sonography with a 20 MHz flexible catheter-based high-resolution real-time miniature transducer in the early first trimester of pregnancy. A total of 15 women about to undergo therapeutic abortion at 7-9.9 weeks gestational age were studied by means of 3D intrauterine sonography with a specially developed catheter-based high-resolution real-time miniature (2.4 mm in outer diameter) ultrasound transducer (20 MHz). This imaging system can provide conventional 2D intrauterine sonographic images and can also generate within seconds high-quality 3D images in the surface and transparent mode. At week 8, prominent forehead was evident, and upper and lower limbs and midgut herniation were clearly depicted. At week 9, fingers and toes were depicted as small digital rays, and the sacral tail protruded caudally. The midline cranial ectodermal cleft was also identified. At week 10, embryonic face and fingers were clearly shown. 3D intrauterine sonography provides a novel means for visualizing of surface anatomic structures of the human embryo in utero. These results suggest that 3D intrauterine sonography can become an important modality in future embryological research and in detection of embryonic developmental disorders in the early first-trimester pregnancy.

Embryo, Mammalian↗
PubMed1998

Maternal and fetal nitric oxide synthesis is decreased in pregnancies with small for gestational age infants.

Our purpose was to evaluate whether maternal and fetal nitric oxide synthesis in pregnancies with small for gestational age (SGA) infants are different from those in pregnancies with appropriate for gestational age (AGA) infants. Maternal and fetal circulating nitrate and nitrite concentrations were compared between 30 pregnancies with AGA and 10 pregnancies with SGA at birth. End-products of nitric oxide synthesis were measured in maternal and cord venous blood samples using a fluorometric assay. Umbilical artery blood pH and PO2 were also measured. Maternal circulating nitrite and nitrate concentrations (6.91 +/- 1.27 microM) in pregnancies with SGA were significantly lower than those (11.69 +/- 1.33 microM) in pregnancies with AGA (P = 0.015). Fetal circulating nitrite and nitrate concentrations (7.54 +/- 1.09 microM) in pregnancies with SGA were also significantly lower than those (11.24 +/- 1.08 microM) in pregnancies with AGA (P = 0.024). There were no significant differences in umbilical artery blood pH and PO2 between the two groups. These results suggest that maternal and fetal nitric oxide synthesis are decreased in pregnancies with SGA infants.

Adult↗
PubMed1998

Power Doppler enhancement of the placenta by dehydroepiandrosterone sulphate in term pregnancy.

We studied the effect of dehydroepiandrosterone sulphate (DHAS) on placental blood flow in 11 women with an uncomplicated pregnancy between 37 and 39 weeks of gestation. Power Doppler enhancement of the placenta was performed before and 60 minutes after the administration of a 200 mg intravenous dose of DHAS dissolved in 20 mL of 5% dextrose. Increased power Doppler enhancements of the placenta after DHAS injection were evident in each case studied. The power Doppler enhancement returned to the baseline imaging within 60 minutes. This DHAS loading test, assessed by means of power Doppler imaging, may be a useful technique when attempting to assess fetoplacental function in normal and high risk pregnancies.

Acetone↗
PubMed1998

Three-dimensional sonographic visualization of the fetal face.

OBJECTIVE: This study was done to show the potential of using three dimensional (3D) sonography to reveal fetal facial anomalies. SUBJECTS AND METHODS: Ninety-four healthy fetuses from 15 to 40 weeks' gestation were studied with a specially developed 3.5-MHz abdominal 3D transducer. This imaging system provided conventional two-dimensional (2D) sonographic images and also generated within seconds high-quality 3D images in the surface and transparent modes with no need for an external workstation. RESULTS: Using this imaging system, we obtained 2D and 3D images of fetal faces (forehead, eyes, nose, lips, and chin) at six gestational ages. At less than 24 weeks' gestation, 65% of facial structures were visualized. The image quality was slightly degraded because of the small fetal size. At or after 24 weeks' gestation, 84% of facial structures were revealed. We found no significant difference in image quality of the fetal face between 2D and 3D sonography. CONCLUSION: The new 3D sonographic technology can generate within seconds high-quality 3D images of the fetal face. The 3D technology seems to perform at least as well as conventional 2D sonography. Our results suggest that 3D sonography has the potential to supplement 2D sonography and might be useful in identifying malformations of the fetal face and chromosomal abnormalities in utero.

Face↗
PubMed1998

Effectiveness of simplified dentin bonding systems.

The effectiveness of newly developed commercial dentin bonding systems (SB, MB II and KB) was evaluated by measuring the contraction gap width of a resin composite restored into a cylindrical dentin cavity prepared in an extracted human molar and by measuring the tensile bond strength to the flat dentin surface. In addition, calcium loss during dentin conditioning was analyzed using electron microanalyses. An experimental dentin bonding system composed of EDTA conditioning, GM solution priming and a bonding agent containing 10-MDP was employed as a control in which it was presumed that contraction gap formation was prevented completely. However, gap formation was observed using the three commercial simplified dentin bonding systems. SEM observation showed that the gap was formed between the resin composite and the top surface of the dentin cavity wall indicating that the fracture occurred at the adhesive interface, but never inside the dentin nor inside the resin composite.

Calcium↗
PubMed1998

Cavity adaptation of resin composite in canine cavity in vivo.

The efficacy of four commercial and two experimental dentin bonding systems was examined by observing the cavity adaptation of commercial light-cured resin composites restored in the dogs scheduled to be sacrificed after a medical experiment. Before being sacrificed, a cylindrical class V cavity was prepared in each canine, and the cavity wall was treated with one of four commercial dentin bonding systems according to the manufacturers instructions followed by resin composite filling. The maximum contraction gap widths at the occlusal, gingival and axial cavity wall were measured on the cavity section 30 min after the polymerization of the resin composite under a light microscope. Contraction gap formation was completely prevented in only one of the experimental groups in which the cavity wall was primed with 35 vol% glyceryl mono-methacrylate (GM). In addition, observation of cavity adaptation in the canine in vivo was useful to estimate consistently the efficacy of the bonding systems.

Alkanes↗