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T Taoka

Publications and source records attributed to T Taoka.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cine-magnetic resonance imaging evaluation of communication between middle cranial fossa arachnoid cysts and cisterns.

Cine-magnetic resonance (MR) imaging examinations were performed in 10 patients with middle cranial fossa arachnoid cysts to evaluate communication between the cysts and the normal cerebrospinal fluid (CSF) space. Eight of 10 patients were evaluated by time of flight cine-MR imaging, and two by phase contrast cine-MR imaging. Two patients underwent membranectomy of the cysts, and were evaluated both pre- and postoperatively. Computed tomography cisternography was used to confirm communication between the cysts and the surrounding cisterns. Pulsatile fluid motion within the cysts was present in all patients. However, marked fluid motion and jet flow between the cysts and the surrounding cisterns were only observed in communicating cysts. In the two patients who underwent membranectomy, postoperative examination found greater fluid motion and jet flow not previously present. Cine-MR imaging demonstration of marked pulsatile fluid motion accompanied by jet flow suggests that a cyst communicates with the normal CSF space.

Adult↗
PubMed1996

[Correlation between MR imaging and histopathological findings of cystic metastatic brain tumors].

To clarify the correlation between the histopathological findings and MR signal intensity of the cyst wall, fifteen cystic metastatic brain tumors of eleven patients were imaged using a 0.5T MR unit just before surgery, and the MRI findings were correlated with the histopathological findings of resected lesions. On T2-weighted images, all cyst walls showed hypointensity. On T1-weighted images, the intensity of the cyst wall could be classified into three groups, compared with the cerebral cortex. Walls with hyperintensity on T1WI(group H; n = 6) consisted of ample tumor cells, blood vessels and connective tissues, suggesting viable tumor cells. Iso-intense walls on T1W1(group I; n = 3)had abundant reactive glial tissues. Hypointense walls on T1W1 (group L; n = 5)revealed hemorrhage and/or hemosicerin in the wall, suggesting hemorrhagic necrosis. Thus a good correlation was demonstrated between the MR signal intensities and histopathological findings of cyst walls of cystic metastatic brain tumors. This may contribute not only to more precise diagnosis on MRI but also to more planning for treatment of cystic brain metastases.

Adenocarcinoma↗
PubMed1994

[A case of Hangman's fracture associated with vertebral arteriovenous fistula treated with trapping].

A case of a traumatic vertebral arteriovenous fistula associated with a hangman's fracture is reported. A 45-year-old male fell down about 2 meters and struck his parietooccipital region against the ground. Profuse nasal bleeding developed. He was transferred to a local hospital, where his respiration was ataxic and blood pressure was low. After intubation, he was transferred to our emergency department. Cervical x-p revealed fracture of C1, C2 and subluxation of C2 body. Because of uncontrollable nasal bleeding, the bilateral maxillary arteries were embolized with spongel. At this time, right vertebral angiograms demonstrated a vertebral arteriovenous fistula with an pseudoaneurysm located at C2 level. On the 13th hospital day, direct balloon occlusion of the fistula was attempted; this could not be achieved because the subclavian and vertebral arteries were tortuous and the balloon catheter could not be introduced to the level of the fistula in the vertebral artery. The patient was only observed until follow-up angiogram on the 24th hospital day revealed enlargement of the pseudoaneurysm. We performed trapping of both the proximal and distal ends of the involved vertebral artery; from C5 to C1. Postoperative course was uneventful, hangman's fracture was fixed with a Halo vest. Four months after operation, fistula and pseudoaneurysm were not opacified on angiogram. We believe that transvascular techniques are the treatment of choice for vertebral arteriovenous fistulas. However, as the next best thing, we can use trapping for the patient whose vessels are too tortuous to introduce the balloon catheter to the involved vessel.

Arteriovenous Fistula↗
PubMed1993

Alkaline phosphatase activity in the human promyelocytic leukemia cell line, HL-60, induced by retinoic acid and recombinant human granulocyte colony-stimulating factor.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) not only enhanced the growth of HL-60 cells, but also significantly increased NBT-reducing ability and alkaline phosphatase (ALP) activity of the cells, which were enhanced by the treatment with retinoic acid (RA). Protein kinase C inhibitors (H-7 and staurosporine) significantly suppressed this induction of ALP. The pretreatment with RA followed by rhG-CSF treatment showed almost the same degree of ALP activity as that induced by the simultaneous treatment with RA and rhG-CSF. This study suggests that RA and rhG-CSF are the potent inducers of ALP activity of HL-60 cells and protein kinase C is supposed to have a role in this induction of ALP.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

1,25(OH)2-vitamin D3 mediated changes in mRNA for c-myc and 1,25(OH)2D3 receptor in HL-60 cells and related subclones.

HL-60 cells have been shown to differentiate into monocyte-like cells as a consequence of the interaction of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) with a specific intracellular receptor (VDR). Of c-myc it has been reported that it plays a role in cell proliferation and differentiation. We have investigated the expression of VDR and c-myc mRNA of three subclones of HL-60 cells (N, R and MR) after exposure to 1,25(OH)2D3. The N cell is a normal clone in which 1,25(OH)2D3 inhibited cell proliferation and also induced cell differentiation. The R cell is a resistant clone whose proliferation and differentiation are not affected by 1,25(OH)2D3. The MR cell is a mixed response type clone whose proliferation was not inhibited by 1,25(OH)2D3, while its differentiation was actually induced by 1,25(OH)2D3. The VDR mRNA expression of the N and MR cells reached a peak at 2 h (2.3- and 2.6-fold induction, respectively) and returned to the control level after 24 h treatment of 1,25(OH)2D3. The c-myc mRNA expression was significantly inhibited in the 1,25(OH)2D3-induced N cells, but not in the MR cells. In contrast, 1,25(OH)2D3 did not induce any changes of the VDR and c-myc mRNA levels in the R cells. In separate experiments, the level of the VDR in the three clones was determined via Scatchard analysis; the VDR of the N, MR and R cells were found to be 4500/cell, 3570/cell and less than 600/cell, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitriol↗
PubMed1993

Streptococcus mitis septicemia in leukemia patients; clinical features and outcome.

The frequency of streptococcal infections has been reported to be increasing. To determine the significance of such infections complicating treatment of leukemia, we studied the incidence and clinical features of Streptococcus mitis septicemia among 51 leukemia patients in our department. During 166 consecutive treatment courses for leukemia, eight episodes of Streptococcus mitis septicemia were observed in 35 septicemic patients. In seven out of eight episodes (88%), severe mucositis developed after aggressive chemotherapy, suggesting that oral mucosa might be the site of entry for Streptococcus mitis. The isolates were sensitive to imipenam/cilastatin and cefuzonam, and were relatively resistant to amikacin. Although none of the patients died of Streptococcus mitis septicemia, life-threatening adult respiratory distress syndrome (ARDS) developed in two independent treatment courses. We should thus be aware of the risk of ARDS in patients with Streptococcus mitis septicemia.

Adolescent↗
PubMed1993

[Six cases of therapy related leukemia; case reports and review of the literature].

The following presents 6 cases of therapy related leukemia (TRL) along with discussion of their clinical features in comparison with those previously reported in Japan. Common primary malignancies were mammalian cancer, lung cancer and malignant lymphoma in both groups. It was observed that, 1) average age was higher (68 years), 2) average latent period from primary malignancy to leukemia was longer (10 years), particularly in patients treated solely with radiation, 3) in 4 out of 6 patients (67%) karyotype analysis of leukemia cells showed normal results, but in one case previously administered etoposide, translocation involving 15q+, 17q- was noted, and 4) the CR ratio in our cases was 83%; half the cases are still alive at 10 months of follow-up, while in previously reported cases the CR ratio was 41%, and the median survival time was 12 months according to Kaplan-Meier analysis. Although poor response to conventional chemotherapy has been reported in TRL patients, the present data indicated TRL in some cases to achieve complete response and long-term survival. Aggressive chemotherapy should be considered for such patients.

Aclarubicin↗
PubMed1993

[Hematological study in 27 patients with myelodysplastic syndrome (MDS)].

The clinical, histologic, and cytogenetic features of myelodysplastic syndrome (MDS) were analyzed in 27 patients consisting of 21 males and 6 females (M: F ratio = 3.5:1) whose median age was 60.9 years. Analysis of the peripheral blood of the patients revealed pancytopenia (8 patients), bicytopenia (12), and cytopenia in one cell lineage (5). The patients had high serum iron value and low UIBC value. More than 20% of all erythroid cells in the bone marrow consisted of ringed sideroblasts in not only RARS patients but also RAEB, CMMoL, and RAEB-T patients. Morphological changes of the bone marrow cells were observed in patients with all types of MDS. Eighty percent and 60% of RAEB and RAEB-T patients, respectively, showed trilineage myelodysplasia. Chromosomal abnormalities were observed in 52% of MDS patients. The rate of leukemic transformation was high in RAEB, CMMoL, and RAEB-T patients.

Adult↗
PubMed1993

[Treatment of adult acute lymphoblastic leukemia with DCVP-l-asp protocol].

From 1985 to 1991, 20 patients with adult acute lymphoblastic leukemia (ALL) were treated with the DCVP-l-asp protocol, which consists of daunorubicin, cytosine arabinoside, vincristine, prednisolone, and I-asparaginase. of these 17 patients (85%) achieved complete remission. A Kaplan-Meier analysis predicted that 30% of the patients in remission would remain disease-free at 5 years. Four patients relapsed between 1 and 2.5 years from the start of treatment. The median survival time for the four patients with an abnormal karyotype was 15 months. No meningeal relapses occurred in patients treated with regular CNS prophylaxis. Myelosuppression was severe, but was well tolerated with supportive therapy, and there were no treatment-related deaths. We conclude that DCVP-l-asp is a feasible and effective protocol for adult ALLs including elderly patients. However, new treatment modalities, such as bone marrow transplantation, should be explored in patients with unfavorable prognostic factors.

Adolescent↗
PubMed1992

Characterization, growth, and differentiation of a human myeloid leukemia cell line, TI-1 cell.

A cell line (TI-1) has been established from the peripheral blood of a patient with acute myeloid leukemia (M2). A typical TI-1 cell displayed many abnormalities of its chromosomes, but not the Philadelphia (Ph1) chromosome. Light and electron microscopic examination and histochemical analysis indicated that the TI-1 cells were undifferentiated blast cells, but immunologic marker studies suggested that these cells had myeloid characteristics. The proliferation of TI-1 cells was dependent on the concentration of fetal bovine serum (FBS). Their doubling time was 13.8 hours when they were cultured in a medium containing 10% FBS. Phorbol-12 myristate 13-acetate (PMA) induced the TI-1 cells to differentiate into monocyte-like cells, as judged by their morphologic similarity to monocytes, their adhesion to the culture dish, and their increase of both nitroblue tetrazolium (NBT)-reducing ability and nonspecific esterase (NSE)-activity. PMA significantly inhibited the proliferation and DNA synthesis of TI-1 cells in a dose-dependent manner. The PMA-induced differentiation was significantly inhibited by the protein kinase C inhibitors (H-7, staurosporine). Hemin induced the TI-1 cells to differentiate into erythroid cells. The number of hemoglobin-producing cells and hemoglobin production was increased by hemin treatment. Hemin also inhibited the proliferation of the TI-1 cells. Thus, the TI-1 cell represents a bipotent, granulo-monocytoid, and erythroid cell line. The TI-1 cell line will be a useful model for monocytoid and erythroid differentiation.

Aneuploidy↗
PubMed1992

Acute myelocytic leukemia associated with thrombocytosis and inv 3(q21.3; q26.2) in a case of Grönbland-Strandberg syndrome.

Grönbland-Strandberg syndrome is an inherited connective tissue disorder with cutaneous, ophthalmologic, and systemic manifestations. Here we report a case of AML with thrombocytosis arising in a patient with this syndrome. Karyotypic analysis of bone marrow cells revealed the inversion 3 (q21.3;q26.2). To our knowledge, this is the first report of the association of AML with thrombocytosis and Grönbland-Strandberg syndrome. This might be a coincidental association, but it suggests some interesting speculations regarding the pathogenesis of these diseases.

Chromosome Inversion↗
PubMed1992

1,25(OH)2-vitamin D3, a steroid hormone that produces biologic effects via both genomic and nongenomic pathways.

The hormonally active form of vitamin D is 1,25(OH)2-vitamin D3 [1,25(OH)2D3]. This seco-steroid is the key mediator of the vitamin D endocrine system which produces biological effects in over 28 target tissues. In these target tissues, the biological responses may be generated both by a signal transduction mechanism which involves a nuclear receptor for 1,25(OH)2D3 that modulates gene transcription or a signal transduction pathway which involves rapid opening of Ca2+ channels which are externally located on the plasma membrane. This paper reviews the evidence in support of the pleiotropic effects of this steroid hormone and presents evidence that the receptor of the genomic effects is likely to be separate from the receptor/membrane recognition element which initiates the rapid nongenomic biological effects.

Animals↗
PubMed1992

Post-splenectomy meningitis in patients with lymphoid malignancy.

This report describes pneumococcal meningitis in two splenectomized patients with lymphoid malignancy. Early diagnosis and emergency treatment of pneumococcal infection in splenectomized patients is proven to be of significant value. Prophylactic antibiotics targeted against pneumococcus should be considered for the clinical management of such conditions in splenectomized patients, particularly during cytotoxic chemotherapy.

Adult↗
PubMed1992

[The effects of retinoic acid and recombinant human granulocyte colony-stimulating factor on alkaline phosphatase activity of HL-60 cells].

We examined alkaline phosphatase (ALP) activity in the HL-60 cell induced by retinoic acid (RA) and recombinant human granulocyte colony-stimulating factor (rhG-CSF). rhG-CSF induced a small but significant increase of NBT-reducing ability and ALP activity of the HL-60 cells. Among various inducers of cell differentiation, 1,25(OH)2D3 and dimethylsulfoxide (DMSO) caused the increase of the NBT-reducing ability and the suppression of ALP activity induced by rhG-CSF, while RA enhanced both of them. Protein kinase C inhibitors (H-7 and staurosporine) but not a protein kinase A inhibitor (HA1004) significantly suppressed the ALP activity induced by the simultaneous treatment with RA and rhG-CSF.

Alkaline Phosphatase↗
PubMed1991

Mechanism of transient increase in intracellular concentration of free calcium ions in HL-60 cell differentiation induced by vitamin D3 and phorbol ester.

A promyelocytic leukemia cell line, HL-60, was induced to differentiate into monocyte-macrophage lineage cells by treatment with active vitamin D3 and phorbol esters, and into granulocyte lineage ones by retinoic acid and dimethylsulfoxide. The changes in intracellular concentration of free calcium ions ([Ca2+]i) were measured and analyzed by calcium-imaging analysis with Fura 2-AM. A significant and transient increase in [Ca2+]i was observed in active vitamin D3 and phorbol ester systems; however, no change was detected with retinoic acid and dimethylsulfoxide. This increase was due to the influx of calcium ions from outside of the cells, and L-type calcium channels were shown to mainly contribute to this influx. Protein kinase C was also shown to be involved in the increase in [Ca2+]i.

Calcitriol↗
PubMed1990

Induction of differentiation of HL-60 cells by protein kinase C inhibitor, K252a.

To clarify the role of protein kinase C and protein kinase A in cell proliferation and differentiation, the effects of K252a and its derivatives (K252b, KT5720), which have different inhibitory activity to these protein kinases, on the proliferation and differentiation of HL-60 cells were investigated. The proliferation and DNA synthesis of the HL-60 cells were inhibited by K252a in a dose dependent manner. However, K252b and KT5720 which are more specific inhibitors of protein kinase C or protein kinase A, respectively, had no observable effect on cell proliferation. K252a (40nM) enhanced the differentiation of HL-60 cells induced by 1,25(OH)2D3, retinoic acid and DMSO. K252b and KT5720 did not affect 1,25(OH)2D3-induced differentiation. K252a significantly inhibited the differentiation induced by PMA. These results demonstrate that K252a but not its derivatives can function as an antitumor drug and enhancer of the differentiation induced by various inducers.

Carbazoles↗