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Biomedical subjects

T Kudoh

Publications and source records attributed to T Kudoh.

At least 19 recordsLinked to original sources
PubMed2004

Pattern of collaterals, type of infarcts, and haemodynamic impairment in carotid artery occlusion.

BACKGROUND: In internal carotid artery (ICA) occlusion, increased oxygen extraction fraction (OEF) indicates inadequate collateral blood flow distal to the occlusion, which may be caused by poor function of collateral pathways. In ICA occlusion, the circle of Willis may be the major collateral pathway, while the collaterals through the ophthalmic artery and leptomeningeal vessels may be recruited when collateral flow through the circle of Willis is inadequate. Conversely, ischaemic lesions may affect the adequacy of collateral blood flow by reducing the metabolic demand of the brain. OBJECTIVE: To determine whether the pattern of collateral pathways and the type of infarcts are independent predictors of OEF in ICA occlusion. METHODS: We studied 42 patients with symptomatic ICA occlusion. The presence of Willisian, ophthalmic, or leptomeningeal collaterals was evaluated by conventional four vessel angiography. The infarcts on magnetic resonance imaging were categorised as territorial, border zone (external or internal), striatocapsular, lacunar, and other white matter infarcts. The value of OEF in the affected hemisphere was measured with positron emission tomography as an index of haemodynamic impairment. RESULTS: Using multivariate analysis, the presence of any ophthalmic or leptomeningeal collaterals and the absence of striatocapsular infarcts were significant and independent predictors of increased OEF. CONCLUSIONS: In patients with symptomatic ICA occlusion, the supply of collateral flow, which is affected by the pattern of collateral pathways, and the metabolic demand of the brain, which is affected by the type of infarct, may be important factors determining the severity of haemodynamic impairment.

Aged↗
PubMed2003

Successful induction of immune tolerance in a patient with haemophilia B with inhibitor.

We describe successful induction of immune tolerance (IT) in a 10-month-old boy with severe haemophilia B. Urticaria developed soon after starting prophylactic treatment and was associated with an inhibitor at 7 Bethesda units mL(-1). Initially, we tried low dose factor IX therapy to induce IT with only a transient effect. The patient experienced an intracranial haemorrhage. A simple bolus dose of FIX eradicated the inhibitor. Thereafter he has been free from inhibitor and nephrotic syndrome for more than 5 years, although he receives FIX three times a week.

Drug Administration Schedule↗
PubMed2002

[Right atrial lipoma with calcification in ascending aorta; report of a case].

A 67-year-old male was diagnosed to have a right atrial tumor by echocardiography incidentally. Computed tomography (CT) indicated a mass which showed very low radiodensity and magnetic resonance imaging (MRI) [T1-weighted] showed the high signal intensity of tumor. We could predict the mass as lipoma. Tumor removal was performed under cardio-pulmonary bypass and under ventricular fibrillation because of the calcification in ascending aorta. Microscopically the tumor was consisted of mature adipose tissue. The postoperative course was uneventful. Cardiac lipomas are rare tumors. CT and MRI are better investigations for preoperative diagnosis. After surgical excision the prognosis is excellent.

Aged↗
PubMed2001

Role of the iroquois3 homeobox gene in organizer formation.

In zebrafish, the organizer is thought to consist of two regions, the yolk syncytial layer (YSL) and the shield. The dorsal YSL appears to send signals that affect formation of the shield in the overlying mesendoderm. We show here that a domain of dorsal deep cells located between the YSL and the shield is marked by expression of the iro3 gene. As gastrulation proceeds, the iro3 positive domain involutes and migrates to the animal pole. Iro3 expression is regulated by Nodal and bone morphogenic protein antagonists. Overexpression of iro3 induced ectopic expression of shield-specific genes. This effect was mimicked by an Iro3-Engrailed transcriptional repressor domain fusion, whereas an Iro3-VP16 activator domain fusion behaved as a dominant negative or antimorphic form. These results suggest that Iro3 acts as a transcriptional repressor and further implicate the iro3 gene in regulating organizer formation. We propose that the iro3-expressing dorsal deep cells represent a distinct organizer domain that receives signals from the YSL and in turn sends signals to the forming shield, thereby influencing its expansion and differentiation.

Amino Acid Sequence↗
PubMed2001

Assessment of the effect of revascularization early after CABG using ECG-gated perfusion single-photon emission tomography.

When an arterial graft is used, reversible perfusion defects on single-photon emission tomography (SPET) perfusion images are occasionally observed early after coronary artery bypass graft surgery (CABG), owing to the restricted flow capacity. The purpose of this study was to determine whether the functional information obtained with electrocardiography (ECG)-gated perfusion SPET could be helpful in evaluating the effect of revascularization early after CABG. Twenty-three patients (18 men and 5 women, mean age 65+/-9 years) underwent stress/re-injection thallium-201 ECG-gated SPET before and 4 weeks after CABG (13 with exercise and 10 with dipyridamole). Patency of all grafts was confirmed by coronary angiography 1 month after CABG. Cardiac functional data including the left ventricular ejection fraction (LVEF) and the transient ischaemic dilatation (TID) ratio were analysed using a commercially available automated program. The conventional stress and re-injection tomograms were interpreted by means of a five-point scoring system in a nine-segment model. Stress-induced reversible 201Tl perfusion defects were present in 64% of the myocardial segments bypassed by patent arterial grafts, in contrast to 42% of the myocardial segments bypassed by patent venous grafts (chi2=7.8, P=0.005). Of the 23 patients, 12 showed improvement in summed ischaemic scores (group 1), while 11 had no change or deterioration (group 2), although all grafts were patent on postoperative catheterization. The TID ratio improved in both group 1 and group 2 before and after CABG (1.14+/-0.13 vs 0.99+/-0.07, P=0.001 and 1.09+/-0.07 vs 0.94+/-0.05, P=0.002, respectively). However, LVEF did not significantly improve in group 1 or group 2 after CABG (42.5%+/-9.9% vs 47.5%+/-11.8%, and 52.1%+/-7.5% vs 53.1%+/-5.9%, respectively). Perfusion imaging or LVEF assessment is of limited value early after CABG. The TID ratio obtained with ECG-gated perfusion SPET may be a useful marker to evaluate the effect of revascularization early after surgery.

Aged↗
PubMed2001

Zebrafish mab21l2 is specifically expressed in the presumptive eye and tectum from early somitogenesis onwards.

Random screening for tissue specific genes in zebrafish by in situ hybridization led us to isolate a gene which showed highly restricted expression in the developing eyes and midbrain at somitogenesis stages. This gene was very similar to mouse and human mab21l2. The characteristic expression pattern of mab21l2 facilitates a detailed description of the morphogenesis of the eyes and midbrain in the zebrafish. In the eye field, mab21l2 expression illustrates the transformation of the eye field to form two separate eyes in the anterior neural plate. Mab21l2 staining in the cyclopic mutants, cyc and oep, exhibited incomplete splitting of the eye primodium. In the midbrain, mab21l2 is expressed in the tectum, and its expression follows the expansion of the tectal region. In mutants affecting the mid-hindbrain boundary (MHB), mab21l2 expression is affected differentially. In the noi/pax2.1 mutant, mab21l2 is down-regulated and the size of the tectum remains small, whereas in the ace/fgf8 mutant, mab21l2 expression persists although the shape of the tectum is altered.

Amino Acid Sequence↗
PubMed2001

Successful unrelated cord blood transplantation in Philadelphia chromosome positive acute lymphoblastic leukemia during pulmonary aspergillosis treated by anti-fungal therapy, granulocyte colony-stimulating factor-mobilized granulocytes and surgical resection: case report.

A 3-year-old girl with Philadelphia chromosome positive acute lymphoblastic leukemia developed pulmonary aspergillosis during severe neutropenia by re-induction therapy. She was treated by intravenous fluconazole, oral itraconazole with plasma level monitoring and surgical resection of the focus for 3 months after clinical diagnosis of fungal infection was made. Once she had recovered from surgery we attempted to induce remission with anti-fungal treatment. She developed fever and neutropenia and appeared unlikely to remit with conventional chemotherapy. Unrelated one-antigen-mismatched cord blood (CB) transplantation was performed 2 months after the induction therapy. Her pulmonary aspergillosis was reactivated during subsequent conditioning. Anti-fungal drugs were switched to amphotericin B and granulocyte colony-stimulating factor-mobilized granulocyte concentrates were transfused. She obtained engraftment and has maintained complete hematological and molecular remission without signs of aspergillus infection for 13 months so far after transplantation. Even very high-risk transplantation in pediatric patients could be successfully supported by carefully designed intense comprehensive medical care.

Amphotericin B↗
PubMed2001

A gene expression screen in zebrafish embryogenesis.

A screen for developmentally regulated genes was conducted in the zebrafish, a system offering substantial advantages for the study of the molecular genetics of vertebrate embryogenesis. Clones from a normalized cDNA library from early somitogenesis stages were picked randomly and tested by high-throughput in situ hybridization for restricted expression in at least one of four stages of development. Among 2765 clones that were screened, a total of 347 genes with patterns judged to be restricted were selected. These clones were subjected to partial sequence analysis, allowing recognition of functional motifs in 163 among them. In addition, a portion of the clones were mapped with the aid of the LN54 radiation hybrid panel. The usefulness of the in situ hybridization screening approach is illustrated by describing several new markers for the characteristic structure in the fish embryo named the yolk syncytial layer, and for different regions of the developing brain.

Animals↗
PubMed2000

Zebrafish nma is involved in TGFbeta family signaling.

Bone morphogenetic proteins (BMP) are members of the TGFbeta superfamily of secreted factors with important regulatory functions during embryogenesis. We have isolated the zebrafish gene, nma, that encodes a protein with high sequence similarity to human NMA and Xenopus Bambi. It is also similar to TGFbeta type I serine/theronine kinase receptors in the extracellular ligand-binding domain but lacks a cytoplasmic kinase domain. During development, nma expression is similar to that of bmp2b and bmp4, and analysis in the dorsalized and ventralized zebrafish mutants swirl and chordino indicates that nma is regulated by BMP signaling. Overexpression of nma during zebrafish and Xenopus development resulted in phenotypes that appear to be based on inhibition of BMP signaling. Biochemically, NMA can associate with TGFbeta type II receptors and bind to TGFbeta ligand. We propose that nma is a BMP-regulated gene whose function is to attenuate BMP signaling during development through interactions with type II receptors and ligands.

Activin Receptors, Type I↗
PubMed2000

Significant regional heterogeneity of coronary flow reserve in paediatric hypertrophic cardiomyopathy.

Previous studies have indicated that cardiac events in young patients with hypertrophic cardiomyopathy (HCM) are related to ischaemia rather than to arrhythmia. We measured coronary flow reserve in paediatric HCM and compared the values with those in adult HCM. We studied 12 patients with HCM including six paediatric (<20 years old; mean 13 years) and six adult patients (>20 years old: mean 62 years), and six healthy young adults (mean 29 years) as controls. Every patient underwent magnetic resonance imaging (MRI) for anatomical assessment. Myocardial blood flow at rest and after dipyridamole infusion was measured with dynamic nitrogen-13 ammonia positron emission tomography (PET). Partial volume effect was corrected for using the anatomical data obtained with MRI. In adult patients with HCM, coronary flow reserve in the hypertrophied septal region was not significantly different from that in the non-hypertrophied lateral wall (1.38+/-0.29 vs 1.77+/-0.39, respectively). In the paediatric patients, coronary flow reserve in the hypertrophied septal region was significantly lower than in the non-hypertrophied lateral wall (0.84+/-0.33 vs 2.74+/-0.90, respectively, P<0.01). In addition, coronary flow reserve in adult patients was lower than in control subjects both in the septal wall (1.38+/-0.29 vs 2.94+/-0.35, respectively, P<0.0001) and in the lateral wall (1.77+/-0.39 vs 2.85+/-0.69, respectively, P<0.05). In contrast, coronary flow reserve in paediatric patients was not significantly different from that in control subjects in the lateral wall (2.74+/-0.90 vs 2.85+/-0.69, respectively), while absolute reduction of myocardial blood flow was noted after pharmacological vasodilatation in the hypertrophied septal region. In conclusion, significant regional differences of coronary flow reserve were present in the paediatric patients with HCM. These results suggest that paediatric patients with HCM intrinsically have the potential to experience significant regional ischaemia even in the absence of coronary stenosis.

Adolescent↗
PubMed2000

Simultaneous development of a pineal tumor and an intradural spinal mass during remission of acute lymphocytic leukemia.

A small percentage of children with acute lymphocytic leukemia experience relapse in the central nervous system in spite of prophylaxis. Diffuse leptomeningeal infiltration is common but an intracranial leukemic mass or spinal cord involvement is a rare manifestation. We report a child with acute lymphocytic leukemia who simultaneously developed a pineal tumor and an intradural spinal cord mass as her first relapse. She was successfully managed by comprehensive combined treatment including peripheral blood stem cell transplantation. She remains in continuous complete remission for more than 5 years without further evidence of neurological sequelae.

Child, Preschool↗
PubMed2000

Iodinated free fatty acid and 201T1 uptake in chronically hypoperfused myocardium: histologic correlation study.

UNLABELLED: 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) is a tracer for the evaluation of ischemic heart disease. The purpose of this study was to assess the relationship between 1231-BMIPP uptake and myocardial fibrosis. METHODS: Fifteen patients who underwent cardiac surgery were examined by imaging with 201TI and 123I-BMIPP, and histologic specimens were taken during surgery. The relative uptake of 201TI (%TI) and that of 123I-BMIPP (%BMIPP) were calculated. The percentage of fibrosis (%fibrosis) was analyzed with the specimen. RESULTS: %TI correlated strongly with %fibrosis (r = -0.94; P < 0.001). %BMIPP also correlated significantly with %fibrosis (r = -0.88; P < 0.001), but the change in %BMIPP looked biphasic. In the category of only mild fibrosis, %BMIPP showed a steep decrease. 123I-BMIPP-201TI mismatch was found only for fibrosis <20%. CONCLUSION: 123I-BMIPP gave specific information about metabolic changes that occurred in ischemic myocardium without severe fibrotic changes.

Coronary Disease↗
PubMed2000

Prognostic factors in childhood acute lymphoblastic leukemia in Japan. Japan Association of Childhood Leukemia Study.

A retrospective analysis of children with acute lymphoblastic leukemia (ALL) was performed to evaluate the current status of diagnosis and treatment of ALL in Japanese children. Clinical records of 670 children with ALL were collected and analyzed; these children had been diagnosed between 1991 and 1995 at the 53 institutions in 4 areas participating in the Japan Association of Childhood Leukemia Study. It was found that T-cell ALL was significantly less frequent in Tokai and Hokkaido than in Kansai and Chu-Shikoku. The overall induction rate was 92.4%. The estimated 7-year overall survival rate and event-free survival (EFS) rate were 76.0% +/- 1.9% and 61.4% +/- 2.1%, respectively. EFS rates were significantly different among the geographic areas. In female patients with B-cell precursor (B-pre) ALL and white blood cell counts at diagnosis (WBCsdiag) below 50.0 x 10(9)/L, favorable outcomes were significant. Favorable outcomes were not significant in B-pre ALL patients with a WBCdiag above 50.0 x 10(9)/L or in T-cell ALL patients. The EFS rate for infants was significantly worse than that for patients over 1 year of age. In B-pre ALL, but not in T-cell ALL, it was found that the higher the WBCdiag, the worse the EFS rate. Multivariate analysis showed that the following factors were significantly unfavorable for EFS: the Philadelphia chromosome, an translocations associated with chromosome 11q23, an acute unclassified leukemia, mixed-lineage leukemia, a WBCdiag above 100.0 x 10(9)/L, and male gender. Hyperdiploidy (> 50 chromosomes) was significantly favorable for EFS. For further tailoring of treatment and to improve the outcome in childhood ALL, a prospective large-scale study should be undertaken in Japan.

Age Factors↗
PubMed1999

Assessment of regional and global left ventricular function by reinjection T1-201 and rest Tc-99m sestamibi ECG-gated SPECT: comparison with three-dimensional magnetic resonance imaging.

OBJECTIVES: The purpose of this study was to test the ability of reinjection thallium-201 and rest technetium-99m sestamibi ECG (electrocardiographic)-gated SPECT (i.e., reinjection-g-SPECT [single-photon emission computed tomography] and MIBI-g-SPECT) to determine regional and global functional parameters. BACKGROUND: The ECG-gated perfusion SPECT was reported to provide accurate left ventricular ejection fraction (LVEF) using an automated algorithm. We hypothesized that other various functional data may be obtained using reinjection-g-SPECT and MIBI-g-SPECT. METHODS: Reinjection-g-SPECT, MIBI-g-SPECT, and three-dimensional magnetic resonance imaging (3DMRI) were conducted in 20 patients with coronary artery disease. Regional wall motion (RWM) and wall thickening (RWT) were analyzed using semiquantitative visual scoring by each g-SPECT and 3DMRI. The left ventricular end-systolic and end-diastolic volumes (EDV, ESV) and LVEF estimated by reinjection- and MIBI-g-SPECT were compared with the results of 3DMRI. RESULTS: A high degree of agreement in RWM and RWT assessment was observed between each g-SPECT and 3DMRI (kappa >.70, p < .001). The LVEF values by reinjection- and MIBI-g-SPECT correlated and agreed well with those by 3DMRI (reinjection: r = .92, SEE = 5.9%, SD of differences = 5.7%; sestamibi: r = .94, SEE = 4.4%, SD of differences = 5.1%). The same also pertained to EDV (reinjection: r = .85, SEE = 18.7 ml, SD of differences = 18.4 ml; sestamibi: r = .92, SEE = 13.1 ml, SD of differences = 13.0 ml) and ESV (reinjection: r = .94, SEE = 10.3 ml, SD of differences = 10.3 ml; sestamibi: r = .97, SEE = 6.7 ml [p < .05 vs. reinjection by F test], SD of differences = 6.6 ml [p < .05 vs. reinjection by F test]). CONCLUSIONS: Reinjection- and MIBI-g-SPECT provide clinically satisfactory various functional data. These functional data in combination with the perfusion information will improve diagnostic and prognostic accuracy without an increase in cost or the radiation dose to the patients.

Adult↗
PubMed1999

Use of technetium-99m sestamibi ECG-gated single-photon emission tomography for the evaluation of left ventricular function following coronary artery bypass graft: comparison with three-dimensional magnetic resonance imaging.

In patients who had undergone cardiac surgery (coronary artery bypass graft) and whose hearts showed abnormal movement during the cardiac cycle, we studied the accuracy of functional assessment using ECG-gated single-photon emission tomography (SPET) and the automated software developed by Germano et al. by comparing the findings with magnetic resonance (MR) images acquired three-dimensionally. Sixteen patients who had undergone cardiac surgery underwent 99mTc-sestamibi gated SPET (MIBI-g-SPET) and MRI on the same day. Left ventricular end-diastolic and end-systolic volumes (EDV, ESV) and ejection fraction (LVEF) were measured using MIBI-g-SPET and the aforementioned algorithm. Regional wall thickening was assessed using a four-point scale on MIBI-g-SPET and cine MRI. There was a good correlation between MIBI-g-SPET and MRI in respect of EDV (r=0.89), ESV (r=0.93) and LVEF (r=0.89). A high degree of agreement was found between the wall thickening scores obtained by MIBI-g-SPET and MRI in total segments (kappa=0.62) and in septal segments (kappa=0.67). It is concluded that ECG-gated perfusion SPET can provide regional and global functional information, including absolute volumes, in patients following cardiac surgery.

Aged↗