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Biomedical subjects

T Fujimoto

Publications and source records attributed to T Fujimoto.

At least 271 records · Page 15Linked to original sources
PubMed1996

Internal tandem duplication of the flt3 gene found in acute myeloid leukemia.

We analyzed mRNA expression of the flt3 gene in 30 patients with acute myeloid leukemia (AML) and 50 with acute lymphoblastic leukemia (ALL). Using reverse transcriptase-polymerase chain reaction (RT-PCR), expression of flt3 was observed in 61 patients; 22 (73%) with AML and 39 (78%) with ALL. Among these, five patients with AML (one M2, two M4, and two M5) showed unexpected longer transcripts with a primer combination which could amplify the transmembrane (TM) domain through the juxtamembrane (JM) domain. For those patients who expressed flt3 mRNA, the extracellular domain of the flt3 gene was also examined by RT-PCR, but no length abnormality was seen in this region. We further analyzed the TM domain through the second tyrosine kinase domain by genomic amplifications. The five patients who showed aberrant flt3 transcripts exhibited abnormal longer PCR products in addition to the germline products at a region corresponding to the JM through the first TK (TK1) domains. Sequence analyses of the abnormal RT-PCR products demonstrated that partial sequences were tandemly duplicated. Because all these altered transcripts were in-frame, deduced protein products could be expected. Sequence analyses of the genomic DNA revealed that three of the five patients showed a simple internal duplication within exon 11; one had an internal duplication (26 bp) with a 4-bp insertion; and in the fifth patient, a 136-bp sequence from the 3' part of exon 11 to intron 11 and the first 16-bp sequence of exon 12 were each duplicated with 1-bp insertion. In order to confirm the tumor specificity of these alterations, DNA samples obtained at complete remission were also analyzed in the three patients harboring an flt3 duplication, but no abnormal PCR product other than germline was detected in any of the samples. Our results suggest that an internal tandem duplication at the JM/TK1 domains of the flt3 gene is a somatic change detected preferentially in AML, possibly containing a monocytic component.

Acute Disease↗
PubMed1996

A point mutation in glycoprotein IX coding sequence (Cys73 (TGT) to Tyr(TAT)) causes impaired surface expression of GPIb/IX/V complex in two families with Bernard-Soulier syndrome.

Bernard-Soulier syndrome (BSS) is a rare inherited bleeding disorder which is caused by abnormal expression or function of the glycoprotein (GP) Ib/IX/V complex, a platelet major receptor for von Willebrand factor. We studied four BSS patients in two unrelated families in which the same and novel mutation was found. Flow cytometric analysis showed that GPIX was completely absent but residual amounts of GPIb alpha and GPV were detectable in these patients. We analyzed all coding regions of GPIb alpha, GPIb beta, GPV and GPIX which were amplified from the patients' genomic DNA by the polymerase chain reaction (PCR). In all four cases, we identified a point mutation in the GPIX coding region that changes the codon for cysteine 73 (TGT) to a codon for tyrosine (TAT). Furthermore, we confirmed by a transient expression study that the mutation caused the loss of adequate surface expression of GPIX. Since cysteine might be important for the secondary structure, this mutation of GPIX gene would lead to a dramatic conformational change of GPIX protein, resulting in the reduced surface expression. We concluded that this novel point mutation of the GPIX gene was responsible for BSS in these families.

Adult↗
PubMed1996

[Methotrexate-leucovorin rescue therapy: pharmacological characteristics and clinical effective use].

An antifolate first introduced into the clinic about half decades ago, Methotrexate is effective against a variety of human cancers, when administered alone or in combination with leucovorin rescue at wide-ranging doses and by many different schedules. We know much more about MTX and its molecular and cellular pharmacology and mechanisms of anti-cancer action in light of current knowledge of the biochemistry of folate. This understanding has stimulated novel approaches to the clinical application of the drug and has greatly enhanced its therapeutic efficacy.

Antidotes↗
PubMed1995

Proton magnetic resonance spectroscopy of the left medial temporal and frontal lobes in chronic schizophrenia: preliminary report.

Proton magnetic resonance spectroscopy (MRS) was performed in 30 medicated schizophrenic patients and 30 normal subjects. Two groups, each containing 15 schizophrenic patients and 15 age-and sex-matched normal subjects, received MRS examinations for different volumes of interest, either the frontal lobe or the medial temporal lobe. Schizophrenic patients showed a decrease in the ratios of N-acetylaspartate (NAA)/choline-containing compounds (Cho) and NAA/creatine-phosphocreatine (Cr). The patients also showed an increase in the ratio of Cho/Cr in the left medial temporal lobe but not in the left frontal lobe. The age at onset of illness correlated positively with the ratios of NAA/Cho and NAA/Cr in the medial temporal lobe. No significant correlation was observed between the ratios of NAA/Cho, NAA/Cr, or Cho/Cr in the left medial temporal and frontal lobes and clinical symptomatology as assessed by the Scale for the Assessment of Negative Symptoms and the Positive and Negative Syndrome Scale.

Adult↗
PubMed1995

50-kD integrin-associated protein does not detectably influence several functions of glycoprotein IIb-IIIa complex in human platelets.

A 50-kD integrin-associated protein (IAP) has been reported to be associated with beta 3 integrins and to modulate their function, especially vitronectin receptor in human erythroleukemia (HEL) cells and leukocyte response integrin in neutrophils. We studied the involvement of IAP in the function of platelet beta 3 integrin, glycoprotein (GP) IIb-IIIa complex. IAP was a widely distributed protein and was also expressed in the cells that do not have beta 3 integrin. Platelets from a patient with thrombasthenia, which lack GPIIb and IIIa, expressed IAP as well as normal platelets. Neither platelet aggregation nor intracellular Ca2+ elevation after stimulation was influenced by the anti-IAP antibody, B6H12, which was reported to be inhibitory for other beta 3 integrins. The expression level of GPIIb-IIIa complex was not influenced by coexpression of human IAP in the transfected Chinese hamster ovary (CHO) cells. IAP did not facilitate the binding of soluble fibrinogen to the CHO cells expressing GPIIb-IIIa complex. Furthermore, cell adhesion onto the immobilized fibrinogen via GPIIb-IIIa complex was not inhibited by B6H12 in HEL cells and was not altered by coexpression of human IAP in CHO cells. We concluded that expression of IAP is regulated independently with that of GPIIb-IIIa complex and that IAP does not influence the function of GPIIb-IIIa complex.

Animals↗
PubMed1995

Cell cycle progression and phenotypic modification of Ki67 antigen-negative G1- and G2-phase cells in phorbol ester-treated Molt-4 human leukemia cells.

To elucidate the relationship between the level of cellular Ki67-reactive antigen and cell proliferation, the effects of 12-O-tetra-decanoylphorbol 13-acetate (TPA) on Ki67 expression, cell cycle progression, and surface phenotypes of human T-lymphoblastic leukemia Molt-4 cells were investigated by multiparameter flow cytometry. The Ki67 antigen is constitutionally expressed in almost all untreated exponentially proliferating Molt-4 cells. Treatment with 10 nM TPA prolonged the duration of the cell cycle time and resulted in a progression arrest of cells in G1- and G2-phases, during which Ki67 expression was decreased to an undetectable level. However, in TPA-treated cultures, the Ki67-positive fraction was invariably smaller than the growth fraction as estimated from continuous 5-bromodeoxyuridine (BrdUrd) labeling curves. This discrepancy could be explained by the finding that some Ki67-negative G1 cells do not enter the resting state but instead remain in the cycling compartment. These results show that Ki67 expression of tumor cells with relatively long G1 duration is downregulated to undetectable levels in late G1-phase and the difference in the level of Ki67 expression between late G1 cells and resting G1 cells is undetectable by conventional immunological methods. Although TPA induced differentiation of Molt-4 cells into mature suppressor T cells, the phenotypic modification was not correlated with cell cycle position and Ki67 reactivity of the cells. These results suggest that growth arrest and phenotypic differentiation of Molt-4 cells are independent effects of TPA.

Antigens, CD↗
PubMed1995

Lack of the expression of EBNA-2 and LMP-1 in T-cell neoplasms possessing Epstein-Barr virus.

We investigated 34 cases of T-cell neoplasm [15 cases of T-cell granular lymphocytic leukemia (T-GLL), 10 cases of T-cell non-Hodgkin's lymphoma (T-NHL), six cases of T-cell chronic lymphocytic leukemia (T-CLL), and three cases of cutaneous T-cell lymphoma] to study their association with Epstein-Barr virus (EBV). In 4 (three T-NHL and one T-GLL) of 34 cases, EBV genome was detected in a single episomal form, while polyclonal EBV-DNA was detected in one (T-NHL) of the remaining cases. All three cases of T-NHL having monoclonal EBV episome showed histologically diffuse large-cell lymphoma and developed leukemic conversion. Phenotypic analysis showed that two of these four cases were CD4+, CD8-, and the remaining two cases were CD4-, CD8+. The cells from all four cases were confirmed to be in T-cell lineage by detecting the rearrangement of T-cell receptor (TCR) beta or gamma chain gene. By reverse transcription-polymerase chain reaction (RT-PCR), EBNA-1 was detected at low levels, and neither EBNA-2 nor LMP-1 were found in any of the three cases examined. Lack of the expression of EBNA-2 and LMP-1 was also confirmed by immunocytochemical staining. The cells of these four cases did not show rearrangement or overexpression of c-myc and bcl-2 genes by Southern and Northern blots, and the mutation of p53 gene was detected in only one patient. These results suggest that other latent gene products of EBV or other cellular oncogenes are involved in the development of Japanese T-cell neoplasm after EBV infection.

Antigens, Viral↗
PubMed1995

Non-invasive method to detect motor unit contractile properties and conduction velocity in human vastus lateralis muscle.

The contractile properties and conduction velocity of motor units are estimated by using surface array electrodes during voluntary isometric contractions of the human vastus lateralis muscle. The subjects develop and maintain sufficient force to steadily discharge a given motor unit, assisted by visual feedback from an oscilloscope. The torque curve developed around the knee joint is triggered by an individual motor unit and averaged. 31 motor units in five subjects are studied. The twitch tension detected ranges from 3 to 27 m Nm with a mean of 12.3 m Nm. The threshold force ranges from 1.88 to 10.12 Nm with a mean of 5.48 Nm, which is 3% of the maximal voluntary contraction. The rise time ranges from 56 to 106 ms with a mean of 83 ms. The mean value of conduction velocity is 4.64 m s-1. The twitch tension is positively correlated to the threshold force (r = 0.839, p < 0.01), but has no relation to the other parameters. It is concluded that the use of non-invasive surface array electrodes provides the contractile properties of motor units and muscle fibre conduction velocity during weak contractions.

Electromyography↗
PubMed1995

A lack of intestinal pacemaker (c-kit) in aganglionic bowel of patients with Hirschsprung's disease.

Recent experimental studies in mice have shown that the proto-oncogene c-kit plays a key role in the development of a component of the pacemaker system that is required for generation of autonomic gut motility. These studies further suggest that interaction of the c-kit receptor and its ligand (stem cell factor, SCF) is critical for the development of the enteric nervous system. The authors investigated the presence of c-kit-positive (c-kit+) cells as well as the expression of SCF in bowel from 12 patients with Hirschsprung's disease (HD), 4 patients with total colonic aganglionosis (TCA), 2 patients with extensive aganglionosis (EA) and 14 controls. Our methods involved the use of immunohistochemistry with antihuman c-kit sera and antihuman SCF sera. A few c-kit+ cells were found in the muscle layers of aganglionic bowels from HD, TCA and EA, in contrast to many c-kit+ cells in ganglionic bowel segments from control, HD, and TCA patients. Expression of SCF was identified in the muscle layers as well as in myenteric plexus of ganglionic bowel, in contrast to its absence in the muscle layers of aganglionic bowel specimens. A lack of c-kit and SCF might be of significance for autonomic gut dysmotility in aganglionic bowel segments of patients with HD and allied disorders such as chronic idiopathic intestinal pseudo-obstruction.

Cell Adhesion Molecules↗
PubMed1995

Degeneration of intrahepatic bile duct with lymphocyte infiltration into biliary epithelial cells in biliary atresia.

Degenerative changes of intrahepatic bile ducts with lymphocytic infiltration into portal areas have been recognized as the characteristic histopathologic features in the liver with biliary atresia (BA). Occasionally, lymphocytic infiltration into biliary ductal epithelium was noted and has been thought to be mostly the result of nonspecific chronic inflammation. However, this histological presentation looks quite similar to that of acute graft-versus-host disease (GVHD) after bone marrow transplantation (BMT) or acute cellular rejection (ACR) after orthotopic liver transplantation (OLTx). According to this histological similarity, we presumed that the degeneration of intrahepatic bile ducts (DIBD) might have developed with lymphocytic infiltration into biliary epithelial cells (LIBE) as some part of an immunologic reaction, and focused on the DIBD with LIBE in the patients with BA. Liver specimens obtained from 31 patients with BA at the time of primary Kasai operation and 3 patients at the time of reoperation were reviewed histologically, and investigated DIBD with LIBE. Nine patients with choledochal cyst (CBD) and 5 patients with neonatal hepatitis (NH) were added to this study as a control population. All patients with BA presented with DIBD with LIBE. On the other hand, only 2 patients with CBD presented with DIBD with LIBE, and no patients with NH presented with DIBD with LIBE. The DIBD with LIBE is not limited to patients with BA, but it seems to be much more serious in this group. These findings may suggest that some sort of immunologic factors contribute to the persistent DIBD in the patients with BA.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile Ducts, Intrahepatic↗
PubMed1995

Quantitative analysis of neuronal innervation in the aganglionic bowel of patients with Hirschsprung's disease.

Although there is marked proliferation of nerve fibers in the aganglionic bowel of patients with Hirschsprung's disease (HD), controversy exists as to whether these fibers terminate in the cells of the bowel wall. This study quantitates biochemically the synaptic vesicle proteins and neurofilaments in the aganglionic bowel of HD patients. The bowel specimens obtained from 12 patients with HD (mean age, 4.6 months) and nine age-matched controls were analyzed by Western blot analysis using monoclonal antibody 171B5 against the synaptic vesicle 38,000-d protein (SVP38), and the specific band obtained was quantitated by densitometry. Similarly, using monoclonal antibody NF70K for detecting the 70,000-d component of neurofilament (NF70), nerve fibers were quantitated. In the aganglionic HD bowel, the quantity of SVP38, representing a proportion of synapses, was significantly lower than that in the normoganglionic bowel (P < .001). The quantity of NF70, representing a proportion of nerve fibers, was significantly greater than that in the normoganglionic bowel (P < .05). These findings suggest that the nerve fibers in the aganglionic bowel of HD patients have much less developed connections with the cells of the bowel wall, indicating overall poor innervation, despite marked proliferation of the nerve fibers.

Blotting, Western↗
PubMed1995

Improved treatment results of non-Hodgkin's lymphoma in children: a report from the Children's Cancer and Leukemia Study Group of Japan.

From 1985 to 1989, 69 patients with non-Hodgkin's lymphoma (NHL) were treated by members of the Children's Cancer and Leukemia Study Group of Japan with a protocol consisting of vincristine, prednisolone, cyclophosphamide, doxorubicin, high-dose methotrexate (HD-MTX), mercaptopurine and cytarabine; central nervous system (CNS) prophylaxis with intrathecal MTX and hydrocortisone (NHL855). The 4-year event-free survival (EFS) was 78% (S.E., 10%) for patients with localized disease (n = 18) and 38% (S.E., 7%) for those with advanced disease (n = 51). Among the patients with advanced disease, those with non-lymphoblastic lymphoma tended to have a better 4-year EFS than those with lymphoblastic lymphoma (52% vs. 25%). Based on these findings, we initiated a new protocol NHL890 in which patients were assigned to two different chemotherapies according to the histology. Non-lymphoblastic subtype was treated almost identically to NHL855 while asparaginase and VP-16 were newly added in the consolidation-maintenance phase in advanced-stage lymphoblastic lymphoma. Sixty-seven patients with advanced disease were assessable. The overall 4-year EFS for advanced disease improved to 69% (S.E., 6%). A significant improvement was gained in the lymphoblastic lymphoma with a 4-year EFS of 56% (S.E., 11%) as compared with 25% (S.E., 9%) in the preceding study (P < 0.05). These findings suggest the importance of histology in the treatment of advanced-stage non-Hodgkin's lymphoma in childhood.

Adolescent↗
PubMed1995

Redistribution of fodrin in an in vitro wound healing model of the corneal epithelium.

We previously observed the redistribution of a membrane skeletal protein, fodrin, after wounding in the corneal epithelium in vivo. In this study, we made an in vitro wound healing model using cultured corneal epithelial cells to investigate the redistribution mechanism of fodrin in the corneal epithelial cells. The distributional change of fodrin from the plasmalemma to the cytoplasm was observed soon after wounding by indirect immunofluorescence microscopy and laser scanning confocal microscopy. A similar change was caused by treating intact cells with phorbol-12-myristate-13-acetate (PMA), but not with calcium ionophore, A23187. The redistribution occurred even in cells pretreated with 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetomethyl ester (BAPTA-AM) before wounding. The redistribution caused by wounding or by PMA was inhibited by pretreating the cells with protein kinase C inhibitors, H-7 or calphostin C. Moreover, the reagents were found to slow down the migration of corneal epithelial cells after wounding. These results suggest that the redistribution of fodrin in the wounded corneal epithelium is caused through the activation of protein kinase C and might be related to the ensuing cell migration.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Effects of enalapril on left ventricular mass and diastolic function in essential hypertension: special reference to duration of hypertension.

Using M-mode and pulsed Doppler echocardiography, the effects of enalapril on left ventricular (LV) hypertrophy and diastolic dysfunction in essential hypertension and the relation between improvement in these two parameters and duration of hypertension were evaluated. The subjects, 30 previously untreated hypertensive patients, were divided into nonhypertrophy (18 patients) and hypertrophy (12 patients) groups. All patients received enalapril at a daily dose of 5 to 10 mg for 6 months. Left ventricular mass by M-mode echocardiography and LV inflow (LVIF) velocity by transthoracic pulsed Doppler echocardiography were measured before and after enalapril therapy. In the nonhypertrophy group, enalapril significantly increased peak early diastolic LVIF (E) velocity (P < .05), slightly lowered peak atrial systolic LVIF (A) velocity, significantly decreased their ratio (A/E) (P < .01), and significantly shortened both the deceleration time, from the peak of the early diastolic wave, and isovolumic relaxation time (P < .05 and P < .01, respectively). In the hypertrophy group, enalapril significantly increased E (P < .05), slightly lowered A, significantly decreased A/E (P < .05), slightly shortened the deceleration time and isovolumic relaxation time, and slightly decreased LV mass. The administration of enalapril correlated significantly and positively with the duration of hypertension and the rates of change in A/E and LV mass in all of the hypertensive patients (P < .01 and P < .05, respectively). These results suggest that long-term administration of enalapril to hypertensive patients improves LV diastolic hemodynamics regardless of the presence or absence of LV hypertrophy and that the effects are most remarkable in patients with the shortest duration of hypertension.

Angiotensin-Converting Enzyme Inhibitors↗