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Takahiro Maeda

Publications and source records attributed to Takahiro Maeda.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of clinical markers of atherosclerosis in young and elderly Japanese adults.

BACKGROUND: In order to be able to take preventative measures early in life against the development of atherosclerosis, it is important to evaluate profiles of subclinical atherosclerosis, especially among young adults. METHODS: We screened plasma homocysteine levels, highly sensitive C-reactive protein levels and carotid intima-media thickness in young and elderly adults. RESULTS: Among both young and elderly adults, plasma homocysteine and highly sensitive C-reactive protein were significantly lower in females than in males. Highly sensitive C-reactive protein was significantly lower in young adults than in elderly adults, and homocysteine was lower (but not significantly) in young adults than in elderly adults. Among young adults, mean carotid intima-media thickness was lower (but not significantly) in females than in males. Among elderly adults, mean carotid intima-media thickness was significantly lower in females than in males. Among both males and females, mean carotid intima-media thickness was significantly higher in elderly adults than in young adults. CONCLUSIONS: These results demonstrate basic profiles of atherosclerosis markers in young and elderly Japanese adults. Further study is needed to evaluate measures developed for application in early adulthood to prevent atherosclerosis.

Adult↗
PubMed2006

[Adult bacterial meningitis complicated by cerebral infarction: report of three cases].

Fatality rates and the number of patients suffering from the after sequelae of bacterial meningitis have still remained high despite the development of new antibiotics. Cerebrovascular complications have been reported less frequently in adult cases than in child cases. We experienced 3 consecutive cases of bacterial meningitis in adults complicated by brain infarction. Primary causative organism were the Group B Streptococci in one case and the Streptococcus pneumoniae in other two cases. MRI, especially with FLAIR method and of coronal view, disclosed abnormal intensity areas near the brain surface. Conventional angiography and MR-angiography in the two cases showed tapering and stenosis of arteries. These cases suggest that routine use of MRI/ MRA in bacterial meningitis reveal neuro-vascular complications more frequently and easily. The benefits of adjunctive steroid therapy in the treatment of bacterial meningitis might be beneficial to suppression of these neurovascular complication cased by inflammatory vasculitis.

Aged↗
PubMed2005

The transcription factor Pokemon: a new key player in cancer pathogenesis.

Learning how critical cell regulatory pathways are controlled may lead to new opportunities for cancer treatment. We recently identified the transcription factor Pokemon as a central regulator of the important tumor suppressor ARF. Pokemon is overexpressed in multiple human cancers and cells lacking Pokemon are refractory to oncogenic transformation. These findings suggest that Pokemon may offer an effective new target for cancer therapeutics.

Animals↗
PubMed2005

Role of the proto-oncogene Pokemon in cellular transformation and ARF repression.

Aberrant transcriptional repression through chromatin remodelling and histone deacetylation has been postulated to represent a driving force underlying tumorigenesis because histone deacetylase inhibitors have been found to be effective in cancer treatment. However, the molecular mechanisms by which transcriptional derepression would be linked to tumour suppression are poorly understood. Here we identify the transcriptional repressor Pokemon (encoded by the Zbtb7 gene) as a critical factor in oncogenesis. Mouse embryonic fibroblasts lacking Zbtb7 are completely refractory to oncogene-mediated cellular transformation. Conversely, Pokemon overexpression leads to overt oncogenic transformation both in vitro and in vivo in transgenic mice. Pokemon can specifically repress the transcription of the tumour suppressor gene ARF through direct binding. We find that Pokemon is aberrantly overexpressed in human cancers and that its expression levels predict biological behaviour and clinical outcome. Pokemon's critical role in cellular transformation makes it an attractive target for therapeutic intervention.

Animals↗
PubMed2005

A novel plasmacytoid dendritic cell line, CAL-1, established from a patient with blastic natural killer cell lymphoma.

Blastic natural killer (NK) cell lymphoma corresponding to CD4+CD56+ malignancies is a novel disease entity, according to the results of clinical, morphologic, and immunologic studies. It is especially noteworthy that this disease likely arises from plasmacytoid dendritic cells (pDCs), described previously as plasmacytoid T-cells, which have an important role in innate and adaptive immunity. However, the exact relationship between the tumor cells and pDCs remains to be elucidated. We encountered a patient with typical blastic NK cell lymphoma, which later converted to leukemic manifestations, and tried to establish a cell line using the leukemic cells. We succeeded in establishment of a novel cell line, CAL-1, which originated from the primary malignant cells. The genetic and phenotypic features of CAL-1 cells bear a similarity to those of pDCs, namely, plasmacytoid morphology at light and electron microscopy; negative results for CD11c and lineage-associated markers of CD3, CD14, CD19, and CD16; positive results for HLA-DR, CD4, CD56, CD45RA, and CD123; and negative results for TCR and IgH gene rearrangements. An interesting finding was that CAL-1 cells change morphologically into the mature DC appearance with many long dendrites after short-term culture in the presence of granulocyte-macrophage colony-stimulating factor and interleukin 3. CAL-1 cells can secrete tumor necrosis factor alpha but not interferon alpha. Thus although they do not share in part phenotypic and functional features with their normal counterparts, CAL-1 cells mostly exhibit a striking pDC phenotype. We describe the first novel pDC cell line of CAL-1. This cell line should open the opportunity for study not only of CD4+CD56+ tumor cells but also of pDCs in vitro.

Aged↗
PubMed2005

[Can diffusion tensor imaging predict the functional outcome of supra-tentorial stroke?].

We used diffusion tensor imaging (DTI) to assess wallerian degeneration of the pyramidal tract after the onset of supra-tentorial stroke, and correlation of the extent of Wallerian degeneration with the motor function at 3 months after stroke. Twenty eight patients with supra-tentorial acute stroke were examined, two weeks and one month after stroke by DTI. We measured fractional anisotropy(FA) of affected side/ unaffected side (FA ratio) in the cerebral peduncle. We used modified Rankin Scale (mRS) for assessment of motor function at 3 months after stroke. FA ratio was significantly reduced at 2 weeks after stroke (0.833 +/- 0.146) compared to on admission (0.979 +/- 0.0797). But no significant change of FA ratio was seen between two weeks and one month after stroke in 7 cases examined (0.758 +/- 0.183 vs. 0.754 +/- 0.183). In all patients in whom the FA ratio was under 0.8 at 2 weeks after stroke, motor function showed poor recovery (mRS 4 and 5) at 3 months after stroke. When FA ratio was over 0.8 at 2 weeks after stroke, motor function at 3 months after stroke showed good recovery (mRS 0 to 3) expect for three elderly patients. With the use of DTI, Wallerian degeneration could be detected in the corticospinal tracts at midbrain level during the early phase of supra-tentorial stroke. We conclude that DTI may be useful for early prediction of motor function prognosis in patients with supra-tentorial acute stroke.

Adult↗
PubMed2004

An alternative transcript derived from the trio locus encodes a guanosine nucleotide exchange factor with mouse cell-transforming potential.

By screening cDNA expression libraries derived from fresh leukemic cells of adult T-cell leukemia for the potential to transform murine fibroblasts, NIH3T3, we have identified a novel transforming gene, designated Tgat. Expression of Tgat in NIH3T3 resulted in the loss of contact inhibition, increase of saturation density, anchorage-independent growth in a semisolid medium, tumorigenicity in nude mice, and increased invasiveness. Sequence comparison revealed that an alternative RNA splicing of the Trio gene was involved in the generation of Tgat. The Tgat cDNA encoded a protein product consisting of the Rho-guanosine nucleotide exchange factor (GEF) domain of a multifunctional protein, TRIO, and a unique C-terminal 15-amino acid sequence, which were derived from the exons 38-46 of the Trio gene and a novel exon located downstream of its last exon (exon 58), respectively. A Tgat mutant cDNA lacking the C-terminal coding region preserved Rho-GEF activity but lost the transforming potential, indicating an indispensable role of the unique sequence. On the other hand, treatment of Tgat-transformed NIH3T3 cells with Y-27632, a pharmacological inhibitor of Rho-associated kinase, abrogated their transforming phenotypes, suggesting the coinvolvement of Rho-GEF activity. Thus, alternative RNA splicing, resulting in the fusion protein with the Rho-GEF domain and the unique 15 amino acids, is the mechanism generating the novel oncogene, Tgat.

3T3 Cells↗
PubMed2004

Hydrothermal routes to prepare nanocrystalline mesoporous SnO2 having high thermal stability.

We report simple hydrothermal routes to prepare thermally stable SnO2 particles having high specific surface areas and mesoporosity. The preparation method includes a new combination of synthetic processes: hydrolysis of tin(IV) chloride at 95 degrees C in the absence of alkaline solutions (aqueous NH3 or NaOH), formation of nanocrystalline SnO2, and subsequent hydrothermal treatments at temperatures between 100 and 200 degrees C. After annealing treatments of the hydrothermally treated SnO2 particles at 400 or 500 degrees C, their crystallite sizes remained smaller than 7.7 nm and their specific surface areas were still higher than 110 m2/g, indicative of the high thermal stability against particle growth and sintering. Furthermore, mesoporosity evolved with a relatively narrow pore size distribution typically in the range of 3.0-4.3 nm. The effects of the hydrothermal treatment were explained by uniformization of the particle size that was beneficial to the suppression of particle growth.

Journal Article↗
PubMed2003

Aberrant processing of Fas transcripts in adult T-cell leukemia: a possible role in tumor cell survival.

In adult T-cell leukemia (ATL), tumor cells commonly express abundant membrane-bound Fas antigen. We reported a significant correlation between Fas expression status of ATL patients and their clinical outcome. In the current study, we analyzed the Fas cDNA sequence of the distinctive ATL cases that barely expressed mFas identified during the previous study. According to the results, changes in the Fas amino acid sequence were deduced in two of seven cases. Furthermore, we identified seven novel variants of Fas mRNA produced by alternative splicing. Our data indicates the diversity of Fas gene expression at a mRNA level in ATL.

Alternative Splicing↗
PubMed2003

Echocardiographic investigation of pericardial effusion in a case of anorexia nervosa.

OBJECTIVE: Pericardial effusion has recently been reported as a complication of anorexia nervosa. A distinct pathophysiological cause of it could not be revealed. In some reports, there was a probable correlation between weight gain and reduction of pericardial effusion in anorexia nervosa cases. We encountered a case in which pericardial effusion remitted completely along with body weight increase and normalization of low T3 syndrome. These findings suggest that the reduction of pericardial effusion may correlate with both weight gain and low T3 normalization. Plasma brain natriuretic peptide (BNP) levels were increased in this case despite heart failure, and plasma BNP decreased as pericardial effusion remitted. The measurement of serum BNP level may be a clinical parameter in such a case of pericardial effusion.

Adult↗
PubMed2003

Sleep disturbances and depression in the elderly in Japan.

UNLABELLED: The purpose of the present study was to evaluate the relationship between sleep disturbances and depression in the Japanese elderly. METHODS: These investigations in the Japanese elderly were carried out with the Geriatric Depression Scale, the Pittsburgh Sleep Quality Index, and questions on restless legs syndrome and nocturnal eating disorder. A total of 2023 people (male: 1008; female: 1015; average age: 74.2 +/- 6.3 years) were analyzed by chi2 test and simple and multiple logistic regression. The prevalence of sleep disturbance was 37.3% and that of depression was 31.3%. Female gender and/or older (> or =75 years) age were significantly associated with depression. Characteristics in depressive elderly were poor sleep efficiency, sleep disturbances due to difficulty of initiating sleep (DIS), breathing discomfort, coldness and pain, poor subjective sleep quality and lack of enthusiasm for activities. Sleep disturbances due to using the bathroom, breathing discomfort and coldness and long sleep latency were associated with depression in younger (65-74 years) men. Sleep disturbance due to DIS was associated with depression in older (> or =75 years) men. Sleep disturbance due to pain was associated with depression in younger and older women. Poor sleep efficiency was associated with depression in older women. Poor subjective sleep quality was associated with depression in younger and older men and younger women. Lack of enthusiasm was associated with depression in younger and older men and older women. Restless legs syndrome was statistically significantly associated with depression in younger men. It is concluded that sleep disturbance and depression among the Japanese elderly are closely related symptoms. The features of sleep disturbance with depression differed with sex and age.

Activities of Daily Living↗
PubMed2003

Two cases of adult T-cell leukemia/lymphoma involving the terminal ileum.

We describe two cases of adult T-cell leukemia/lymphoma (ATLL) with terminal ileal involvement. The first case, a 71-year-old man with lymphoma subtype of ATLL, had a polypoid lesion in the terminal ileum, in addition to a duodenal mass. The second case, a 58-year-old woman with lymphoma subtype of ATLL, had an irregular ulcerative lesion in the terminal ileum and multiple ulcers throughout the stomach. Biopsies from these lesions revealed mucosal invasion of ATLL cells in each case. In the second case, combination chemotherapy was transiently effective, resulting in the disappearance of gastric and terminal ileal lesions. Prospective and careful examination of additional cases should further characterize the clinicopathological features of terminal ileal involvement in ATLL.

Aged↗
PubMed2003

A case of mucosa-associated lymphoid tissue lymphoma of the ampulla of Vater: successful treatment with radiation therapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the papilla of Vater is rare, and little is known of either its association with Helicobacter pylori infection or the optimal treatment modalities. We describe the first case of MALT lymphoma involving the major papilla that remained unchanged despite eradication of H. pylori, but which regressed following radiotherapy. A 46-year-old asymptomatic man was admitted to hospital for treatment of MALT lymphoma involving the papilla of Vater. Duodenal endoscopy showed multiple granules around the major ampulla, and biopsies revealed mucosal proliferation of centrocyte-like cells, lymphoepithelial lesions, hyperplastic lymphoid follicles and plasmacytic differentiation. The lymphoma cells were positive for B-cell but negative for T-cell markers, and expressed Bcl-2 but showed no immunoreactivity for CD5, CD10 and cyclin D, consistent with MALT lymphoma. The patient was successfully treated with triple therapy of lansoprazole, amoxicillin and clarithromycin for 1 week for coexisting H. pylori infection in the stomach, but the lymphoma lesions remained unchanged. Then, involved-field irradiation was applied at a total dose of 30 Gy delivered in 1.5 Gy fractions without any adverse events. Six months later, repeat endoscopy revealed disappearance of the granular lesions and lack of lymphoma cells in biopsy specimens. Four years after the commencement of radiotherapy, the patient is still in complete remission. Radiotherapy seems a safe and effective treatment modality for low-grade MALT lymphoma of the ampulla of Vater.

Ampulla of Vater↗
PubMed2003

Successful electroconvulsive therapy in major depression with fluvoxamine-induced bruxism.

SUMMARY: A 61-year-old patient with major depression and selective serotonin reuptake inhibitor-induced bruxism was successfully treated with a course of bilateral electroconvulsive therapy. Both the depressive symptoms and bruxism completely remitted after six treatments. Possible mechanisms of this effect are discussed.

Antidepressive Agents, Second-Generation↗