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Biomedical subjects

M Umeda

Publications and source records attributed to M Umeda.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Combined deficiency in neutrophil functions after bone marrow transplantation and the in vitro effect of granulocyte colony-stimulating factor].

In order to investigate the mechanism of susceptibility to bacterial infection after bone marrow transplantation (BMT), we evaluated the neutrophil functions at 1, 3, 6, and 12 months after hematological reconstitution in a 29-year-old AML patient who received allogeneic bone marrow transplantation. Acute graft-versus-host disease (GVHD) was grade I, and chronic GVHD was not present. The patient exhibited complications of upper and lower respiratory infections several times after BMT, all of which subsided within a month. Chemotactic responses toward all three chemotactic factors, random mobility, phagocytosis, superoxide (O2-) release and bactericidal activity were severely impaired early after reconstitution. These neutrophil functions gradually improved with time after BMT, and all normalized at 12 months after reconstitution of transplanted bone marrow. Both O2- release and bactericidal activity of neutrophils were significantly enhanced at 6 and 12 months after marrow reconstitution following pretreatment of 50 ng/ml of granulocyte colony-stimulating factor (G-CSF) in vitro. These findings suggest that the combined disorders in neutrophil functions in early phase after BMT may play an important role in susceptibility to bacterial infections until one year after BMT. Administration of G-CSF, which potentiates the bactericidal activity of neutrophils, is recommended for preventing infectious complications and for treating prolonged and unmanageable infections after BMT.

Adult↗
PubMed1997

[Non-Hodgkin's lymphoma associated with cold agglutinin disease].

Autoimmune hemolytic anemia (AIHA) complicated with non-Hodgkin's lymphoma (NHL) is not unusual. Two cases of NHL associated with cold agglutinin disease were reported. Case 1: A 38-year-old man had diffuse medium-sized cell NHL diagnosed by cervical lymph node biopsy. The Hb was 7.6 g/dl with a cold agglutinin titer of 32,768, and the IgM level was 890 mg/dl (I-specific), so cold agglutinin disease (CAD) was suspected. After administration of COP-BLAM therapy, complete remission (CR) was achieved along with a decrease in the cold agglutinin titer and improvement of anemia. Case 2: A 68-year-old woman had follicular mixed NHL diagnosed by inguinal lymph node biopsy. The Hb was 8.2 g/dl with a cold agglutinin titer of 51,200, and an IgM level of 920 mg/dl (I specific), thus concurrent CAD was suspected. Biweekly COP-BLAM therapy was administered and CR was achieved along with a decrease in the cold agglutinin titer and improvement of her anemia. In both patients, the cold agglutinin titer decreased after CR was achieved suggesting that production of anti-erythrocyte autoantibody was due to disturbance of the antibody system by NHL.

Adult↗
PubMed1997

Neplanocin A, a potent inhibitor of S-adenosylhomocysteine hydrolase, potentiates granulocytic differentiation of acute promyelocytic leukemia cells induced by all-trans retinoic acid.

Several neplanocin A analogs were synthesized and their growth-inhibiting and differentiation-inducing activities on myelogenous leukemia cells were examined. An adenosine kinase-ineffective analog of neplanocin A was effective in inducing differentiation, suggesting that phosphorylation of the nucleoside is not essential for inducing the differentiation of leukemia cells. Neplanocin A induced functional and morphological differentiation of HL-60 cells, but did not effectively induce differentiation of NB4, a cell line derived from a leukemia patient with t(15;17). However, these cells have been known to undergo granulocytic differentiation upon treatment with all-trans retinoic acid (ATRA), and are used as a model for differentiation therapy in acute promyelocytic leukemia. Preexposure of NB4 cells to low concentrations of neplanocin A greatly enhanced the ATRA-induced differentiation of the cells, whereas representative antileukemic drugs such as cytosine arabinoside and daunomycin did not enhance this differentiation. A clinical strategy that combines intermittent treatment with neplanocin A analogs and a low dose of ATRA may increase the clinical response and decrease the adverse effects of ATRA.

Adenosine↗
PubMed1997

[Three-dimensional brain mapping using fMRI].

Functional mapping of the activated brain, the location and extent of the activated area were determined, during motor tasks and sensory stimulation using fMRI superimposed on 3 D anatomical MRI. Twelve volunteers were studied. The fMR images were acquired using a 2 D gradient echo echo planar imaging sequence. The 3D anatomical MR images of the whole brain were acquired using a conventional 3D gradient echo sequence. Motor tasks were sequential opposition of fingers, clenching a hand and elbow flexion. Somatosensory stimulation were administered by scrubbing the palm and sole with a washing sponge. Visual stimulation consisted of full visual field stimulation. Data were analyzed by the cross-correlation method. Transversal fMR images and anatomical images were reconstructed using both volume-, surface-rendering methods, and reconstructed for coronal and sagittal sections. Activated areas were expressed using the three primary colors. Motor tasks activated the contralateral primary motor area (M1), the primary somatosensory area (S1) and the supplementary motor area (SMA). Somatosensory tasks activated the contralateral S 1, M1 and secondary sensory area (S2). Activated areas during full visual field stimulation was observed in the bilateral occipital lobe, including both the primary cortex. Three-dimensional brain mapping allowed visualization of the anatomical location and extent of the activated brain during both motor task and sensory stimulation. Using this method we could obtain a functional map similar to the Penfield's schema.

Adult↗
PubMed1997

Follow-up of two cases of Papillon-Lefèvre syndrome and presentation of two new cases.

Periodontitis resulting from Papillon-Lefèvre Syndrome has been known to cause early loss of primary dentition with subsequent involvement of the permanent dentition. In this study, two Papillon-Lefèvre Syndrome patients were followed for 3 years after initial treatment and improvement of their periodontal condition. In addition, two new cases of Papillon-Lefèvre Syndrome are presented. The follow-up treatment of the first two patients included monitoring the oral hygiene and performing ultrasonic scaling. Their present clinical appearance is very satisfactory. The periodontal condition of the third (new) patient was brought under control by extracting the involved deciduous teeth under antibiotic coverage, and by scaling and root planing the already erupted permanent teeth as well as by maintaining a high standard of oral hygiene. In the fourth case, all permanent teeth had erupted and the periodontium had already been severely destroyed. Actinobacillus actinomycetemcomitans was not detected by microbiologic examination after the periodontal conditions improved, except in the fourth case. Western blot analysis showed that the three first three patients had positive antibody response to the same antigens of Actinobacillus actinomycetemcomitans. Phagocytosis by polymorphonuclear neutrophil leukocytes) had not decreased, but the expression of surface receptors of polymorphonuclear neutrophil leukocytes was within the normal limits.

Aggregatibacter actinomycetemcomitans↗
PubMed1996

Redistribution of phosphatidylethanolamine at the cleavage furrow of dividing cells during cytokinesis.

Ro09-0198 is a tetracyclic polypeptide of 19 amino acids that recognizes strictly the structure of phosphatidylethanolamine (PE) and forms a tight equimolar complex with PE on biological membranes. Using the cyclic peptide coupled with fluorescence-labeled streptavidin, we have analyzed the cell surface localization of PE in dividing Chinese hamster ovary cells. We found that PE was exposed on the cell surface specifically at the cleavage furrow during the late telophase of cytokinesis. PE was exposed on the cell surface only during the late telophase and no alteration in the distribution of the plasma membrane-bound cyclic peptide was observed during the cytokinesis, suggesting that the surface exposure of PE reflects the enhanced scrambling of PE at the cleavage furrow. Furthermore, cell surface immobilization of PE induced by adding the cyclic peptide coupled with streptavidin to prometaphase cells effectively blocked the cytokinesis at late telophase. The peptide-streptavidin complex treatment had no effect on furrowing, rearrangement of microtubules, and nuclear reconstitution, but specifically inhibited both actin filament disassembly at the cleavage furrow and subsequent membrane fusion. These results suggest that the redistribution of the plasma membrane phospholipids is a crucial step for cytokinesis and the cell surface PE may play a pivotal role in mediating a coordinate movement between the contractile ring and plasma membrane to achieve successful cell division.

Animals↗
PubMed1996

Extended fitness of variable region primers by a novel PCR protocol.

In an attempt to isolate the variable region genes of five monoclonal natural autoantibodies, we failed to amplify all ten variable region cDNAs using a V region primer set and following conventional PCR protocols. A novel PCR procedure was established in which the reaction began with three cycles of low temperature annealing and chain extension using 5'-primer as the only primer present, and continuing with conventional PCR cycles following addition of 3'-primer. Combined with solid-phase cDNA synthesis on oligo(dT)cellulose, this new protocol rescued all failed PCR amplifications based on a conventional protocol, thereby extending the universal utility of the V region primers. A notable increase in amplification specificity was also achieved. Such a protocol could be useful in primer design and the amplification of non-antibody genes whose sequences are not well-understood.

Animals↗
PubMed1996

Stimulation of endothelial cell migration in culture by ladsin, a laminin-5-like cell adhesion protein.

Ladsin is a laminin-like cell-adhesive scatter factor with potent cell motility-stimulating ability and was purified from serum-free conditioned medium of a malignant human gastric adenocarcinoma cell line STKM-1. To test its possible role in tumor angiogenesis, we investigated its effect on primary culture of endothelial cells (human umbilical vein endothelial cells) and endothelial cell line ECV304 in this study. Cell adhesion and motility effects of ladsin were observed in both types of endothelial cells. In cell-attachment assay, ladsin interacted with integrin alpha 3 beta 1 that was expressed on the endothelial cell surface. In Boyden chambers, ladsin stimulated both directed and random migration of ECV304 cells. Ladsin induced repair of artificial wounds generated in ECV304 cell monolayers by stimulating cell migration. Ladsin did not affect the growth rate of ECV304 cells at a low cell density but significantly increased the saturation cell density. These results suggest that ladsin may be involved in the adhesion and migration of endothelial cells under some physiological and pathological conditions.

Cell Adhesion↗
PubMed1996

Discrimination of brain abscess from necrotic or cystic tumors by diffusion-weighted echo planar imaging.

Diagnostic difficulties in discriminating brain abscess from necrotic or cystic tumors using conventional CT and MRI have been reported. In this article, we examine the diagnostic ability of diffusion-weighted imaging to discriminate brain abscess from necrotic or cystic tumors. In previous reports, necrotic or cystic tumors show low signal intensity in diffusion-weighted imaging, indicating a high apparent diffusion coefficient (ADC). In contrast, in our study, high signal intensity was observed in the abscess fluid, associated with low ADC.

Brain Abscess↗
PubMed1996

Purification and identification of a novel and four known serine proteinase inhibitors secreted by human glioblastoma cells.

Our previous studies have shown that some human cancer cell lines produce pancreatic trypsinogen, plasminogen, and tissue-type kallikrein. To understand the regulatory mechanism of these proteinases, serine proteinase inhibitors secreted by human glioblastoma cell line T98G were analyzed by gelatin reverse zymography with trypsin. The serum-free conditioned medium of T98G cells showed more than ten trypsin inhibitor bands ranging from 16 to 150 kDa in the reverse zymography. Major trypsin inhibitors were purified by trypsin-affinity chromatography. Analysis of their N-terminal amino acid sequences demonstrated that the purified inhibitors were identical to the secreted forms of amyloid protein precursors (APPs), tissue factor pathway inhibitor (TFPI), placental protein 5 (PP5)/TFPI-2, and secretory leukocyte proteinase inhibitor (SLPI). In addition, a novel 25-kDa trypsin-binding protein, tentatively named p25TI, was identified. p25TI showed weak inhibitory activity against trypsin in reverse zymography as compared with the other inhibitors. The secretion of multiple forms of serine proteinase inhibitors by human cancer cells raises the possibility that they might be involved in the abnormal growth of cancer cells.

Amino Acid Sequence↗
PubMed1996

Detection frequencies and the colony-forming unit recovery of oral treponemes by different cultivation methods.

Selected media were compared for primary isolation and detection of oral treponemes from clinical samples. Forty-eight subgingival plaque samples from 45 patients suffering from periodontitis were anaerobically cultivated for 2 weeks at 37 degrees C. Of the 9 media studied, Medium 10 (M10), which was supplemented with 10% rabbit serum and incubated using the plate-in-bottle method, supported the highest colony-forming units of the anaerobes. The treponemal colonies were detected at least on one medium from 83% of the subgingival plaque samples. The new oral spirochete medium in an anaerobic chamber supported the highest detection frequency of the oral treponemes (64% of samples); however, M10 in the plate-in-bottle was found to produce the highest colony-forming unit recovery of the oral treponemes (median 3.6% of the total colony-forming units). This study suggests that M10 in the plate-in-bottle and new oral spirochete medium in the anaerobic chamber are essential in cultivating oral treponemes.

Anaerobiosis↗
PubMed1996

Biweekly COP-BLAM (cyclophosphamide, vincristine, prednisone, bleomycin, doxorubicin and procarbazine) regimen combined with granulocyte colony stimulating factor (G-CSF) for intermediate-grade non-Hodgkin's lymphoma.

We evaluated the efficacy and adverse effects of biweekly COP-BLAM (cyclophosphamide, vincristine, prednisone, bleomycin, doxorubicin and procarbazine) therapy combined with granulocyte colony-stimulating factor (G-CSF) for treating non-Hodgkin's lymphoma (NHL). A complete remission was achieved in 65 (90.3%) of the 72 patients. THe median follow-up period was 28 months, and 64 patients were alive at the time of writing. Treatment was delivered as scheduled to 61 patients. G-CSF made it possible to shorten the interval between courses of chemotherapy. One of the 72 patients died of granulocytopenia and pneumonia; no other severe infections were noted. Further studies regarding adverse effects on organs other than the bone marrow are required to improve the long-term results of combination therapy on NHL.

Adult↗
PubMed1996

Salvage chemotherapy for relapsed or refractory non-Hodgkin's lymphoma with a combination of ACES (high-dose Ara C, carboplatin, etoposide and steroids) therapy.

ACES (Ara-C, carboplatin, etoposide, steroids) therapy using granulocyte-colony stimulating factor (G-CSF) was designed for relapsed or refractory non-Hodgkin's lymphoma (NHL), and the therapeutic effects and adverse reactions were studied. The subjects were 40 patients, including 19 relapsed cases and 21 refractory cases, subjected to chemotherapy using anthracycline type agents. The ACES therapy consisted of carboplatin at 100 mg/m2 and etoposide at 80 mg/m2 for 4 d from the first day, Ara-C at 2 g/m2 on the fifth day, solumedrol at 500 mg for 5 d from the first day and G-CSF at 2 micrograms/kg from the seventh day. This therapy was performed every 3 weeks, in principle. The doses were reduced to 70% of the above values for patients aged 70 yr or older. Among the 40 patients, complete remission (CR) was achieved in 14 (35%) and partial remission (PR) in 14 (35%) for a response of 70%. The 50% survival period was 526 d, and the 2-yr disease-free survival rate was 58.3%. Adverse reactions of grade 3 or higher included granulocytopenia in 62.5%, anemia in 17.5% and thrombocytopenia in 50%, but there was no death related to treatment. Four patients underwent transplantation of hematopoietic stem cells and have survived for long periods. This treatment was effective against relapsed NHL and could be performed safely with few adverse reactions.

Adolescent↗
PubMed1996

Evaluation of cytosine arabinoside, carboplatin and etoposide chemotherapy in the treatment of relapsing and refractory non-Hodgkin's lymphoma.

Twenty-eight patients (14 with relapsing and 14 with refractory non-Hodgkin's lymphoma; NHL) were treated with a combination of CACE chemotherapy (cytosine arabinoside, carboplatin, and etoposide) and recombinant granulocyte colony-stimulating factor (G-CSF) to investigate the efficacy and adverse effects of this regimen. Twenty-eight NHL patients (16 men and 12 women, median age 52 years) received intravenous infusions of cytosine arabinoside (100 mg/m2) on days 1-7, carboplatin (250 mg/m2) on day 1, and etoposide (70 mg/m2) on days 1-3, as well as the subcutaneous administration of G-CSF (2 micrograms/kg) beginning on day 9. Eleven of 28 (39.3%) patients achieved complete remission (CR) and 10 patients (35.7%) partial remission (PR). Therefore, a total response rate of 75% was achieved. Nine patients with relapsing disease and 2 with refractory NHL achieved CR. Of the 28 patients 51.5% were alive at 3 years, while the 3-year survival rate for those who achieved CR was 87.5%. The 50% disease-free survival duration was 20.8 months. Adverse effects included leukopenia (2 x 10(9)/l) in 4 patients (14.2%) and thrombocytopenia (50 x 10(9)/l) in 18 patients (64.3%). Although the efficacy of the CACE regimen was demonstrated for treatment of relapsing NHL, the efficacy of CACE was not satisfactory for the treatment of refractory NHL. Further study is required to determine the value of the CACE regimen as therapy for the refractory NHL.

Adult↗
PubMed1996

Transmembrane phospholipid distribution revealed by freeze-fracture replica labeling.

We propose the use of membrane splitting by freeze-fracture for differential phospholipid analysis of protoplasmic and exoplasmic membrane leaflets (halves). Unfixed cells or tissues are quick-frozen, freeze-fractured, and platinum-carbon (Pt/C) shadowed. The Pt/C replicas are then treated with 2.5% sodium dodecyl sulfate (SDS) to solubilize unfractured membranes and to release cytoplasm or contents. While the detergent dissolves unfractured membranes, it would not extract lipids from split membranes, as their apolar domains are stabilized by their Pt/C replicas. After washing, the Pt/C replicas, along with attached protoplasmic and exoplasmic membrane halves, are processed for immunocytochemical labeling of phospholipids with antibody, followed by electron microscopic observation. Here, we present the application of the SDS-digested freeze-fracture replica labeling (SDS-FRL) technique to the transmembrane distribution of a major membrane phospholipid, phosphatidylcholine (PC), in various cell and intracellular membranes. Immunogold labeling revealed that PC is exclusively localized on the exoplasmic membrane halves of the plasma membranes, and the intracellular membranes of various organelles, e.g. nuclei, mitochondria, endoplasmic reticulum, secretory granules, and disc membranes of photoreceptor cells. One exception to this general scheme was the plasma membrane forming the myelin sheath of neurons and the Ca(2+)-treated erythrocyte membranes. In these cell membranes, roughly equal amounts of immunogold particles for PC were seen on each outer and inner membrane half, implying a symmetrical transmembrane distribution of PC. Initial screening suggests that the SDS-FRL technique allows in situ analysis of the transmembrane distribution of membrane lipids, and at the same time opens up the possibility of labeling membranes such as intracellular membranes not normally accessible to cytochemical labels without the distortion potentially associated with membrane isolation procedures.

Animals↗