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Biomedical subjects

M Bessho

Publications and source records attributed to M Bessho.

At least 19 recordsLinked to original sources

A new method for measurement of bone deformation by echo tracking.

No method has been available to noninvasively detect bone deformation or strain under loading in vivo. We focused on ultrasonic measurement of the displacement at a certain point on a bone using the echo-tracking method (ET). To develop a method that can noninvasively detect bone deformation in vivo, a preliminary investigation was performed. We investigated the accuracy of measuring displacement with our echo tracking system by using a flat metal panel and found that the method could measure displacement with a precision of a few microns. A three-point bending test of a porcine tibia with both ends fully constrained was performed to measure bone surface displacement, and simultaneous measurement of the surface strain was done using two strain gauges. The correlation between the displacement measured by ET and the strain gauge readings was completely linear (r=0.999), showing that the method could precisely detect bone deformation. The loads versus displacement curves obtained with cyclic loading were typical hysteresis loops that showed viscoelastic properties of the measured bone. We also improved a multi-ET system capable of simultaneously tracking multiple points to detect deformation of the bone surface. Measurement by this echo tracking system was also compared with strain gauge readings during a three point bending test with both ends of the tibia supported. The linearity of both methods was very high (r=0.998). Our ET method might have considerable potential for noninvasive measurement of bone viscoelasticity and plasticity.

Aluminum↗

I kappa B-mediated apoptotic gene therapy against acute myelogenous leukemia using replication-defective HSV-1 vector expressing TK and mutant I kappa B alpha.

Overexpression of NF-kappa B reportedly plays anti-apoptotic roles in the growth of AML cells. Control of AML cell growth was attempted using a replication-defective herpes simplex virus-1 vector, T0I kappa B alpha, overexpressing mutant I kappa B alpha to inhibit NF-kappa B in vitro. T0I kappa B alpha displays defective ICP4/ICP22/ICP27, isogenic thymidine kinase, and mutant I kappa B alpha. T0Z.1 expressing lacZ instead of I kappa B was used for controls. Infection of T0I kappa B alpha at 15 multiplicity of infection (MOI) with cells of AML lines, HL60, K562, and NB4 displaying >90% infection efficiency and tumor killing in vitro. Use of 10 microM of Ara-C alone was clinically equivalent to high-dose Ara-C, displaying 11% tumor killing. Neither ganciclovir (GCV) nor Ara-C enhanced T0I kappa B- alpha mediated tumor killing. Attenuation of NF-kappa B by T0I kappa B alpha was confirmed by EMSA. T0I kappa B alpha induced caspase-3 activity, with subsequent apoptosis confirmed by colorimetric and TUNEL assays. Fresh AML cells from 8 patients were infected with T0I kappa B alpha at 3 MOI, with or without GCV or 10 microM of Ara-C in vitro. Infection efficiency was 10%. T0I kappa B alpha displayed 8-15% tumor killing, superior to Ara-C in 6 of the 8 patients. Administration of Ara-C enhanced tumor killing in 5 of these 6 cases. Our results suggest that T0I kappa B alpha-mediated gene therapy induces apoptosis of AML cells in vitro.

Adult↗

Serum thymidine kinase and soluble interleukin-2 receptor predict recurrence of malignant lymphoma.

Before and after therapy, serum thymidine kinase (TK) and soluble interleukin-2 receptor (sIL-2R) were serially determined in 28 patients with malignant lymphoma (ML). In 15 patients achieving and maintaining complete remission (CR) for more than 2 years, serum TK and sIL-2R were unchanged or decreased gradually. In contrast, logarithmic linear increases of TK and sIL-2R were observed in 13 relapsed patients. The increments of the serum markers occurred more than 10 months before the relapse. A significant positive correlation between the slope of the line for TK and that for sIL-2R was noted. The doubling time for TK estimated from the slope also showed a positive correlation with that for sIL-2R. Taken together, serum TK and sIL-2R were shown to be quite sensitive and interrelated serum markers for the recurrence of ML. Slopes of logarithmic linear increase, which are proper and specific for the individual patients, are inversely correlated with the doubling time and reflect proliferation of ML. We conclude that serum TK and sIL-2R are better predictors of relapse than LDH and the international prognostic index (IPI).

Adult↗

Fusion of ETV6 to fibroblast growth factor receptor 3 in peripheral T-cell lymphoma with a t(4;12)(p16;p13) chromosomal translocation.

Fusions of the ETV6/TEL gene to receptor or protein tyrosine kinases (TKs), such as PDGFRbeta, JAK2, ABL, ABL2, TRKC, and Syk, have been reported in various hematological malignancies. Expression of the resultant chimeric proteins is believed to lead to constitutive TK activity through activation by the helix-loop-helix (HLH) domain of ETV6. We identified a novel ETV6 partner gene, fibroblast growth factor receptor 3 (FGFR3), in a patient with peripheral T-cell lymphoma (PTCL) with a t(4;12)(p16;p13) translocation. The ETV6-FGFR3 transcript showed a fusion of exon 5 of ETV6 to exon 10 of FGFR3, resulting in an open reading frame for a chimeric protein consisting of the HLH domain of ETV6 and the TK domains of FGFR3. This is the first report of ETV6 and FGFR3 involvement in PTCL.

Amino Acid Sequence↗

[Clinical analysis of neutropenic fever associated with hematological disorders].

We evaluated the efficacy of combination therapy with sulbactam/cefoperazone (SBT/CPZ) and amikacin sulfate (AMK) in eligible patients with hematological disorders of neutrophil count less than 1,000/microliter. The clinical efficacy rate in 157 evaluated patients was 65.6%. The clinical efficacy rates were related to neutrophil counts and serum albumin levels at the 1 week later. The clinical efficacy rates were 87.1% in patients with neutrophil counts over 500/microliter and 34.8% in patients with serum albumin levels under 3 g/dl after 1 week. G-CSF treatment were not significant but tended to be more effective in patients with sepsis, and the neutrophil counts increased significantly. The group using G-CSF before the antibiotic treatment had a high clinical efficacy rate. It is suggested that G-CSF is effective in patients with neutropenia with the high risk to infection and in those who already have severe infections.

Adolescent↗

[Clinical effects of combination therapy with cefozopran and amikacin for infections in patients with hematological disorders].

Cefozopran (CZOP) and amikacin (AMK) were used concomitantly to treat infections complicated by hematological diseases. A total of 103 subjects were evaluated, and the all over efficacy rate was 69.9%. Acute leukemia was found in the largest number of patient, 57, followed by 29 cases of malignant lymphoma and 7 cases of myelodysplastic syndrome. By type of infection, patients having unknown origin were the largest in number, being 66, and the efficacy rate was 71.2%. The efficacy rates for sepsis, pneumonia and upper respiratory infection were 42.9% (7 cases), 71.4% (14 cases) and 90% (10 cases) respectively. The efficacy rates by neutrophil counts before administration of CZOP and AMK and at 1 week after administration were both 53.3% in the group of less than 100/microliter, both 60% in the group of less than 500/microliter. The efficacy rate by neutrophil counts at 1 week after administration was 58.6% in the group of less than 100/microliter. The efficacy rate was 75.4% in the group of granulocyte colony stimulating factor (G-CSF) concomitant usage, and 61.9% in the group of non-concomitant usage group. The efficacy rates by serum albumin levels before administration of CZOP and AMK and at 1 week after administration were both 92.9% in the group of over than 4 g/dl, both 50% in the group of less than 3 g/dl. Concomitant treatment with CZOP and AMK exhibited a high level of safety and efficacy rates in infections complicated by hematological diseases.

Adult↗

[CD7(+) acute myeloid leukemia (M0) associated with a mediastinal bulky mass lesion].

A 41-year-old man visited his doctor in May 2000 because of a sore throat and high fever. His symptoms did not improve, despite administration of antibiotics and nonsteroidal anti-inflammatory drugs. Since a chest X-ray examination revealed an anterior mediastinal bulky tumor, he was referred and admitted to our hospital on June 21, 2000. The peripheral white blood cell count was 44,540/microliter with 74% myeloblasts. Bone marrow aspiration revealed a hypercellular marrow with 82% myeloblasts, which were negative for peroxidase and alpha-naphthyl butylate esterase staining. Blast cells were positive for CD7, CD13, CD33, CD34, and HLA-DR, and negative for CD56. A needle biopsy specimen of the mediastinal tumor consisted of myeloblasts. We diagnosed the patient as having CD7 (+) acute myeloid leukemia (AML) (M0) with a bulky mediastinal mass based on the surface marker analysis, although the clinical features resembled myeloid/NK precursor acute leukemia. The patient achieved a complete remission after two courses of induction therapy. We are planning an allogeneic stem cell transplantation during his first remission because of the high risk of relapse.

Adult↗

[Clinical significance of WHO classification and MDS 2000 classification in myelodysplastic syndromes].

Excluding chronic myelomonocytic leukemia, a total of 92 consecutive patients with myelodysplastic syndrome showing less than 20% blasts in the bone marrow were analyzed. We evaluated the clinical significance of the WHO and MDS 2000 classifications by reviewing each MDS patient according to the classification. The WHO criteria classified the MDS patients into 36 with RA, 22 with RCMD and 33 with RAEB, whereas according to the MDS 2000 criteria there were 19 RAEB-I patients and 15 RAEB-II patients. Based on the WHO classification, the RCMD patients had higher platelet counts and percentages of blasts among BM cells than the RA patients (P = 0.0018, P = 0.0001). Twenty percent of the RA patients, 44.8% of the RCMD patients, and 70.8% of the RAEB patients had cytogenetic abnormalities. Among them, the poor karyotype was present in 6.7% of the RA patients, 21.0% of the RCMD patients and 41.6% of the RAEB patients. The rate of acute leukemia death was 14.3% in the RA patients, 67.7% in the RAEB patients and 50.0% in the RCMD patients. Analysis of survival times revealed significant differences between RA and RCMD patients (P = 0.0482). The clinical features of RCMD patients were intermediate between those of RAEB and RA patients. There was no difference between the clinical features of the RAEB-I and RAEB-II patients in the MDS 2000 classification.

Aged↗

Expression of functional granulocyte colony-stimulating factor receptors on human B-lymphocytic leukemia cells.

We analyzed the expression of cell surface antigens and granulocyte colony-stimulating factor (G-CSF) receptors using flow cytometry, the expression of G-CSF mRNA receptor, using reverse transcription (RT)-PCR, and tested the effect of G-CSF on leukemia colony formation. A total of 14 lymphocytic leukemia patients were examined, seven with acute lymphocytic leukemia (ALL), two with adult T-cell leukemia (ATL), two with B-chronic lymphocytic leukemia (CLL), two with chronic myelocytic leukemia in lymphoid blastic crisis (CML-LBC), and one with plasma cell leukemia (PCL). The presence of G-CSF receptors was demonstrated in 4/14 (29%) patients, two with ALL, one with CLL, and one with CML-LBC, and was associated with stimulation of leukemia clonogenic cell growth by G-CSF. In addition, all four positive leukemia cell types expressed typical B-cell antigens. Our results indicated that G-CSF receptors are expressed on some portion of B-lymphoid leukemia and that their receptors are functional as growth stimulators.

Adolescent↗

Granulocyte-colony stimulating factor induced intranuclear endonuclease in murine leukemia cell line.

We have reported that murine leukemia cell line (C2M-A5) induced apoptosis by G-CSF. To clarify the mechanism, mRNA expression of apoptosis-related genes was studied. It revealed transient over-expression of c-myc, H-ras and p53 and down-expression of bcl-2. These changes were known as triggers of endonuclease induction. After 96 h culture with G-CSF, apoptosis was occurred simultaneously with endonuclease (37 kd) activation. This endonuclease induced the digestion of double-strand DNA and might be associated with caspase3. Although G-CSF accelerates cell growth and prevents apoptosis in general, it is a contradictory effect. We concluded that G-CSF induced endogenous endonuclease activity in C2M-A5.

Animals↗

[Efficacy and safety of cefozopran (CZOP) monotherapy and combination therapy with CZOP and amikacin (AMK) for infections accompanying hematological diseases].

We evaluated efficacy and safety of monotherapy with CZOP (1-2 g x 2/day) and combination therapy with CZOP (1-2 g x 2/day) and AMK (200 mg x 2/day) for infections in patients with hematological diseases. Efficacy was evaluated in 71 patients of monotherapy group and 70 patients of combination therapy group. Underlying diseases were mostly leukemia and lymphoma. Infections included sepsis, suspected sepsis, pneumonia and so on. Efficacy in CZOP monotherapy was excellent in 21 patients (31.3%), good in 23 patients (34.3%), fair in 5 patients (7.5%) and the efficacy rate was 65.7%. On the other hand, in combination therapy, each was 14 patients (21.2%), 23 patients (34.8%), 12 patients (18.2%) and the efficacy rate was 56.1%. Side effects such as eruption were noted in 2 patients. Abnormal laboratory findings were noted in 9 patients. All side effects as well as abnormal laboratory findings were minimal. It was concluded that CZOP monotherapy was effective in the treatment of various infections accompanying hematological diseases.

Adolescent↗

BRCA1-associated growth arrest is RB-dependent.

BRCA1 is a susceptibility gene for breast and ovarian cancer with growth-inhibitory activity for which the mechanism of action remains unclear. When introduced into cells, BRCA1 inhibits growth of some but not all cell lines. In an attempt to uncover the mechanism of growth suppression by BRCA1, we examined a panel of cell lines for their ability to reduce colony outgrowth in response to BRCA1 overexpression. Of all variables tested, only those cells with wild-type pRb were sensitive to BRCA1-induced growth suppression. In cells with an intact rb gene, inactivation of pRb by HPV E7 abrogates the growth arrest imposed by BRCA1. In accordance with these observations, we found that BRCA1 could not suppress BrdUrd uptake in primary fibroblasts from rb-/- mice and exhibited an intermediate ability to inhibit DNA synthesis in rb+/- as compared with rb+/+ cells. We further found that the BRCA1 protein complexes with the hypophosphorylated form of pRb. This binding is localized to amino acids 304-394 of BRCA1 protein and requires the ABC domain of pRb. In-frame deletion of BRCA1 fragment involved in interaction with pRb completely abolished the growth-suppressive property of BRCA1. Although it has been reported that BRCA1 interacts with p53, we find the p53 status did not affect the ability of BRCA1 to suppress colony formation. Our data suggest that the growth suppressor function of BRCA1 depends, at least in part, on Rb.

Adenoviridae↗

Biologic and biochemical analyses of p16(INK4a) mutations from primary tumors.

BACKGROUND: Point mutations in the tumor suppressor gene p16(INK4a) (also known as p16, CDKN2, MTS1, and INK4a) are found in many tumor types. Because the function of the products of these naturally occurring mutants has not been fully explored, we investigated the functional activities of a wide range of naturally occurring p16 mutant proteins. METHODS: Sixteen cancer-associated p16 mutant proteins, resulting from missense mutations, were characterized for their ability to bind and inhibit the cyclin-dependent kinases (CDK4 and CDK6) and to induce cell cycle arrest in G(1) phase. RESULTS/CONCLUSIONS: Among 16 mutants analyzed, nine had detectable functional defects. Three mutants (D84V, D84G, and R87P) had defects in CDK binding, kinase inhibition, and cell cycle arrest. The corresponding mutations are located in the third ankyrin repeat in a highly conserved region believed to form the CDK binding cleft. Three mutants (P48L, D74N, and R87L) had defects in kinase inhibition and cell cycle arrest. Among the 10 mutants with normal CDK binding and inhibitory activity, three mutants (N71S, R80L, and H83Y) had defects only in their ability to induce cell cycle arrest. Thus, p16 mutant proteins that retain CDK4 and CDK6 binding may have more subtle functional defects. All nine mutations leading to functional impairments mapped to the central portion of the p16 protein. Ankyrin repeats II and III appear more critical to p16 function, and mutations in ankyrin repeats I and IV are less likely to disrupt p16 function.

Amino Acid Sequence↗

Fusion of TEL/ETV6 to a novel ACS2 in myelodysplastic syndrome and acute myelogenous leukemia with t(5;12)(q31;p13).

We identified a novel human long fatty acyl CoA synthetase 2 gene, ACS2, as a new ETV6 fusion partner gene in a recurrent t(5;12)(q31;p13) translocation in a patient with refractory anemia with excess blasts (RAEB) with basophilia, a patient with acute myelogenous leukemia (AML) with eosinophilia, and a patient with acute eosinophilic leukemia (AEL). ACS2 is expressed in the brain and bone marrow and is highly conserved in man and rats. The resulting ETV6/ACS2 fusion transcripts showed an out-frame fusion of exon 1 of ETV6 to exon 1 of ACS2 in the AEL case, an out-frame fusion of exon 1 of ETV6 to exon 11 of ACS2 in the AML case, and a short in-frame fusion of ETV6 exon 1 to the 3' untranslated region of ACS2 in the RAEB case. Reciprocal ACS2/ETV6 transcripts were identified in two of the cases. Fluorescence in situ hybridization (FISH) analysis with ETV6 cosmids on 12p13, and BACs and P1s on 5q31, demonstrated that the 5q31 breakpoints of the AML and AEL cases involved the 5' portion of the ACS2 gene, and that the 5q31, breakpoint of the RAEB case involved the 3' portion of the ACS2 gene. None of the resulting chimeric transcripts except for the ACS2/ETV6 transcript in the RAEB case led to a fusion protein. Disruption of the second ETV6 allele by t(12;19) was detected in the AML case by FISH analysis. These observations suggest that the disruption of ETV6 and/or ACS2 may lead to the pathogenesis of hematologic malignancies with t(5;12)(q31;p13).

Adult↗