Biomedical subjects

I Taniguchi

Publications and source records attributed to I Taniguchi.

At least 19 recordsLinked to original sources

PubMed2006

Plasma brain natriuretic peptide concentrations in patients undergoing pulmonary vein isolation.

OBJECTIVE: To examine whether raised plasma brain natriuretic peptide (BNP) concentrations decrease after successful pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). METHODS: 53 patients (mean age 53 years) with drug-refractory, paroxysmal lone AF underwent segmental ostial PVI. Blood samples were collected before and after PVI. BNP concentrations were determined by immunoassays. RESULTS: Median plasma BNP concentrations were significantly higher in patients with lone AF than in controls (patients with supraventricular tachyarrhythmias, n = 21) (64.6 (71.9) v 13.9 (7.8) pg/ml, p < 0.01). AF recurred in 21 patients after the initial PVI procedure (recurrent AF group), and the others were free from AF without antiarrhythmic drugs (non-recurrent AF group). BNP concentrations were significantly decreased by PVI in the non-recurrent AF group (38.9 (39.1) to 18.3 (16.1) pg/ml, p < 0.01) but not in the recurrent AF group. CONCLUSIONS: Raised plasma BNP concentrations decreased after successful segmental ostial PVI in patients with AF.

Atrial Fibrillation↗

PubMed2003

Lymph node hyalinization in elderly Japanese.

Lymph node hyalinization has been comprehensively investigated using specimens obtained from elderly Japanese and white Americans. Onion-peel lesions and associated meshwork areas were often found in the medullary sinus of the thoracic node (mediastinal-type hyalinization), while eosinophilic, glassy and spotty lesions were consistently seen in B lymphocyte areas of the pelvic node (pelvic-type hyalinization). The mediastinal-type hyalinization was comprised of thin collagen fibrils (ca 50 nm in diameter), whereas the pelvic-type hyalinization had thick fibrils (ca 150 nm in diameter). This difference seemed to be consistent with a difference in composite collagen fibrils of vascular walls between the thoracic and pelvic regions. The pelvic-type hyalinization was often or sometimes seen in other nodes, such as cervical, axillary, abdominal and inguinal nodes, especially in white Americans. The mediastinal-type hyalinization, usually in combination with a sinus filled with anthracotic macrophages, tended to be observed in Japanese more frequently than in white Americans. Anthracosis seemed to be connected to the pathogenesis of the hyalinization. On the other hand, because the lesion was weakly positive for Factor VIII immunohistochemistry and because lesions were located along thin vessels, the pelvic-type hyalinization seemed to originate from vascular degeneration in the nodal cortex. Due to the high incidence and large proportion in total volume of the node, the hyalinization seems to be one of the major events that diminish the nodal filtration function and ruin the node with aging.

Aged↗

PubMed2002

[Long time use of percutaneous cardiopulmonary support after cardiovascular operation; clinical problems from our experience].

Result and problems were studied in 12 patients who received percutaneous cardiopulmonary support (PCPS) after cardiac or aortic surgery. Causative diseases included acute myocardial infarction in 7 cases, rupture of the left ventricular septum after infarction, acute mitral valve regurgitation after infarction, rupture of the left ventricular free wall, a stuck valve, and an aortic aneurysm in the thoracicoabdominal region in each 1 case. The time of postoperative PCPS ranged from 2 to 361 hours, and the mean supply flow volume was 1.78 +/- 0.45 l/min/m2. Seven patients could be taken off the treatment or discharged from the hospital (58.3%). The comparison between surviving and non-surviving cases showed a significantly longer assisted circulation time in the latter. An increase of bleeding after surgery was found in all 8 patients who received PCPS for a long period postoperatively. This was assumed to be due to the thrombocytic activation by heparin.

Aged↗

PubMed2001

Cyclin D3 is a target gene of t(6;14)(p21.1;q32.3) of mature B-cell malignancies.

Chromosomal translocation t(6;14)(p21.1;q32.3) has been reported as a rare but recurrent event not only in myeloma and plasma cell leukemia but also in diffuse large B-cell non-Hodgkin lymphoma (B-NHL) (diffuse large B-cell lymphoma [DLBCL]) and splenic lymphoma with villous lymphocytes (SLVL); however, the nature of the target gene(s) has not been determined. This study identified t(6;14)(p21.1;q32.3) in 3 cases of transformed extranodal marginal zone B-NHL, in 1 case of SLVL, and in 1 case of a low-grade B-cell lymphoproliferative disorder. In a sixth case, a CD5(+) DLBCL, the translocation was identified by molecular cloning in the absence of cytogenetically detectable change. Two chromosomal translocation breakpoints were cloned by using long-distance inverse polymerase chain reaction methods. Comparison with the genomic sequence for chromosome 6p21.1 showed breakpoints approximately 59 and 73.5 kilobases 5' of the cyclin D3 (CCND3) gene with no other identifiable transcribed sequences in the intervening region. Although Southern blotting with derived genomic 6p21.1 probes failed to detect other rearrangements, fluorescent in situ hybridization assays, using BAC (bacterial artificial chromosome) clones spanning and flanking the CCND3 locus, along with probes for IGH confirmed localization of 6p21.1 breakpoints within the same region, as well as fusion of the CCND3 and IGH loci. Furthermore, in all cases, high-level expression of CCND3 was demonstrated at RNA and/or protein levels by Northern and Western blotting and by immunohistochemistry. These data implicate CCND3 as a dominant oncogene in the pathogenesis and transformation in several histologic subtypes of mature B-cell malignancies with t(6;14)(p21.1;q32.3) and suggest that CCND3 overexpression seen in about 10% of DLBCL cases may have a genetic basis.

Adult↗

PubMed2001

Optical imaging of neural activity in multiple auditory cortical fields of guinea pigs.

Neural activity of multiple fields in the auditory cortex of anesthetized guinea pigs in response to pure tones was visualized by optical recording using a voltage-sensitive dye (RH795). Ten auditory fields were identified based on the tonotopic organization and response latency: the core fields consisting of the primary (AI) and secondary (AII) fields and surrounding belt areas consisting of dorso-anterior (DA), dorsal (D), dorso-posterior (DP), posterior (P), ventro-posterior (VP), ventro-medial (VM), ventro-anterior (VA) and ventral (V) fields. Tonotopic organization was observed in all the fields apart from DA, D, DP and V. Spatio-temporal displays suggest that the auditory information spreads from the core fields of AI and AII to belt fields via three distinct (dorsocaudal, caudal and ventrorostral) pathways.

Acoustic Stimulation↗

PubMed2001

Quadricuspid aortic valve associated with aortic stenosis and regurgitation.

A 75-year-old man with moderate aortic stenosis and regurgitation admitted due to heart failure underwent uneventful aortic valve replacement with a Carpentier-Edwards pericardial bioprosthesis valve. A quadricuspid aortic valve discovered incidentally during surgery consisted of 4 of different sizes and a supernumerary cusp between the right and noncoronary cusps. No coronary abnormality was involved. Resected cusps showed fibrotic thickening with calcification and no sign of previous inflammatory disease. Although quadricuspid aortic valve is a very rare anomaly, its potential for severe valve failure in adulthood should not be neglected.

Aged↗

PubMed2001

Simultaneous minimally invasive direct coronary artery bypass and repair of a penetrating atherosclerotic ulcer of the descending thoracic aorta: report of a case.

A 70-year-old man with a descending aortic aneurysm was admitted to the hospital because of an abnormal chest X-ray. The chest computed tomography and magnetic resonance angiography findings showed a saccular aneurysm at the descending thoracic aorta. A preoperative coronary arteriogram showed 75% stenosis of the left anterior descending coronary artery and 99% stenosis of the right coronary artery. A simultaneous minimally invasive direct coronary artery bypass (MI

Aged↗

PubMed2001

The DD genotype of angiotensin converting enzyme polymorphism is a risk factor for coronary artery disease and coronary stent restenosis in Japanese patients.

Stent implantation has decreased the incidence of restenosis after coronary intervention, but has not eliminated it. The contribution of the angiotensin-converting enzyme (ACE) genotype to the development of coronary artery disease and restenosis after coronary stenting was investigated in 67 Japanese patients in whom 103 lesions in which stents had been successfully implanted were assessed by quantitative coronary angiography, before, immediately after coronary stenting, and during follow-up. The distribution of the patients with the DD, ID, and II genotypes was 13%, 54%, and 33%, respectively. The prevalence of multivessel disease in the DD genotype was significantly higher (DD genotype: 78%; ID genotype: 58%; II genotype: 27%, chi2=8.13, p=0.016) and the late loss in the DD genotype (1.43+/-0.96 mm) was significantly greater (ID genotype: 0.78+/-0.98 mm and II genotype: 0.79+/-0.88 mm, p<0.05 vs DD genotype). However, there was no significant difference in the restenosis rate among the 3 genotypes. The present study in Japanese patients indicates that the DD genotype is associated with more extensive coronary artery disease and progression of the inward remodeling within the stented lesion, which is primarily caused by neointimal hyperplasia.

Aged↗

PubMed2000

Sex differences in the ventral paleostriatum of the zebra finch: origin of the cholinergic innervation of the song control nuclei.

The two main song control nuclei in the forebrain of zebra finches, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), are sexually dimorphic at many levels of their neural circuitry. These nuclei receive their cholinergic innervation from the ventral paleostriatum (VP), which is homologous to portions of the mammalian basal forebrain. We compared the cholinergic neurons in the VP between the sexes using choline acetyltransferase (ChAT) immunohistochemistry. Both the size and density of the ChAT-immunoreactive somata in areas of the VP that project to the HVC or RA in males were significantly larger than those in females. These sex differences in the VP may be reflected in the sex differences of behaviors such as song perception and production.

Animals↗

PubMed2000

Hemangioma of bone arising in the ulna: imaging findings with emphasis on MR.

An 18-year-old woman presented with left elbow joint pain. Radiographs and computed tomographic scan showed a well-defined osteolytic lesion of the left ulna associated with a honeycomb appearance on the radiographs. Magnetic resonance images showed intermediate signal intensity on T1-weighted images and mixed intermediate and high signal intensities on T2-weighted images. Only the periphery of the lesion enhanced with intravenously injected gadolinium-diethylenetriamine pentaacetic acid. The lesion was curetted to avoid pathologic fracture, and a histologic diagnosis of cavernous hemangioma of bone was made. Hemangioma involving the ulna is rare, but should be included in the differential diagnosis of a radiographic osteolytic lesion with a honeycomb appearance.

Adolescent↗

PubMed2000

Statistical procedures for spatiotemporal neuronal data with applications to optical recording of the auditory cortex.

This article presents new procedures for multisite spatiotemporal neuronal data analysis. A new statistical model - the diffusion model - is considered, whose parameters can be estimated from experimental data thanks to mean-field approximations. This work has been applied to optical recording of the guinea pig's auditory cortex (layers II-III). The rates of innovation and internal diffusion inside the stimulated area have been estimated. The results suggest that the activity of the layer balances between the alternate predominance of its innovation process and its internal process.

Animals↗

PubMed2000

Auditory-vocal cholinergic pathway in the songbird brain.

Male zebra finches learn to imitate a tutor's song through auditory and motor learning. The two main song control nuclei in the zebra finch forebrain, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), receive cholinergic innervation from the ventral paleostriatum (VP) of the basal forebrain which may play a key role in song learning. By injecting neuroanatomical tracers, we found a topographically segregated pathway from nucleus ovoidalis (Ov) to VP that in turn projects in a topographic fashion to HVC and RA. Ov is a major relay in the main ascending auditory pathway. The results suggest that the cholinergic neurons in the VP responsible for song learning are regulated by auditory information from the Ov.

Animals↗

PubMed1999

Comparison of the electrostatic binding sites on the surface of ferredoxin for two ferredoxin-dependent enzymes, ferredoxin-NADP(+) reductase and sulfite reductase.

Plant-type ferredoxin (Fd), a [2Fe-2S] iron-sulfur protein, functions as an one-electron donor to Fd-NADP(+) reductase (FNR) or sulfite reductase (SiR), interacting electrostatically with them. In order to understand the protein-protein interaction between Fd and these two different enzymes, 10 acidic surface residues in maize Fd (isoform III), Asp-27, Glu-30, Asp-58, Asp-61, Asp-66/Asp-67, Glu-71/Glu-72, Asp-85, and Glu-93, were substituted with the corresponding amide residues by site-directed mutagenesis. The redox potentials of the mutated Fds were not markedly changed, except for E93Q, the redox potential of which was more positive by 67 mV than that of the wild type. Kinetic experiments showed that the mutations at Asp-66/Asp-67 and Glu-93 significantly affected electron transfer to the two enzymes. Interestingly, D66N/D67N was less efficient in the reaction with FNR than E93Q, whereas this relationship was reversed in the reaction with SiR. The static interaction of the mutant Fds with each the two enzymes was analyzed by gel filtration of a mixture of Fd and each enzyme, and by affinity chromatography on Fd-immobilized resins. The contributions of Asp-66/Asp-67 and Glu-93 were found to be most important for the binding to FNR and SiR, respectively, in accordance with the kinetic data. These results allowed us to map the acidic regions of Fd required for electron transfer and for binding to FNR and SiR and demonstrate that the interaction sites for the two enzymes are at least partly distinct.

Arabidopsis Proteins↗

PubMed1999

Layer-specific horizontal propagation of excitation in the auditory cortex.

Optical imaging was conducted in rat auditory cortex slice preparations to study how horizontal excitation propagates in the cerebral cortex. When a horizontal cut was made between supragranular and infragranular layers, electrical stimulation of layer II/III elicited horizontally propagating excitation in supragranular layers with the same propagating velocities as those seen before a cut was made. Electrical stimulation of layer VI or the border between the white matter and layer VI also elicited horizontally propagating excitation in infragranular layers with the same propagating velocities as those seen before a cut was made. These results suggest that the horizontal propagation of excitation in supragranular and infragranular layers can occur independently in the auditory cortex.

Animals↗

PubMed1999

Outcome of target sites escaping high-grade (>70%) restenosis after percutaneous transluminal coronary angioplasty.

This study examined the fate of target sites that escaped high-grade restenosis (> or = 70% diameter narrowing) after percutaneous transluminal coronary angioplasty. Although favorable long-term prognosis after successful percutaneous transluminal coronary angioplasty is well documented, little is known about the stability of target sites. Long-term follow-up (mean 6.5 years, range 1.0 to 12.0) was performed in 693 patients with 948 narrowings (stenosis <70% in diameter at follow-up coronary angiography). Among them, 249 patients (36%) with 303 target sites received late follow-up coronary angiography. The relation of target sites to the culprit lesions for coronary events or newly developed angina was angiographically reviewed and progression/regression was also examined, focusing on the target sites. Regression was observed in 16 of 255 target sites in subjects with <50% stenosis and in 21 of 48 sites in the group with midgrade stenosis of 50% to 69% luminal narrowing (16 of 255, 6.3% vs 21 of 48, 43.8%, p <0.001). Progression was observed in 33 and 4 sites (33 of 255, 12.9% vs 4 of 48, 8.3%; p = NS) in each group, respectively. The rest remained within the same range of stenosis. Culprit lesions for 2 acute myocardial infarctions, 7 unstable anginas, and 17 newly developed anginas were related to the original target sites. Three lesions developed in the midgrade stenosis group. Those 26 lesions were a component of 8.6% of 303 angiographically confirmed sites and 2.7% of total target sites. Target sites that escape high-grade restenosis frequently regress and become stable plaques and rarely trigger coronary events.

Aged↗

PubMed1999

Pulmonary artery aneurysm.

Main pulmonary artery aneurysm is an exceedingly rare entity. We present a case of main pulmonary artery aneurysm with patent ductus arteriosus in a sixty-year-old woman. The aneurysm was successfully treated with aneurysmectomy and primary anastomosis of the defect of the main pulmonary artery, and the patent ductus arteriosus was divided. The etiology, operative indication and surgical intervention of main pulmonary artery aneurysm are discussed along with a review of the literature.

Anastomosis, Surgical↗

PubMed1999

Spatiotemporal representation of binaural difference in time and intensity of sound in the guinea pig auditory cortex.

Neural activity of the auditory cortex (AC) in response to a change of interaural intensity difference (IID) and interaural time difference (ITD) of sound stimuli was observed by optical recording with a 12 x 12 photodiode array and the voltage-sensitive dye, RH795. Guinea pigs (280-450 g) were anesthetized with sodium pentobarbital (30 mg/kg) and supplemental doses of neuroleptic solutions. When both ears were stimulated dichotically by tone bursts (14 kHz, 75 dB SPL), excitatory optical signals appeared in both anterior (A) and dorsocaudal (DC) fields of AC. An increase of intensity of ipsilateral stimulation from 65 to 95 dB SPL caused a decrease of neural activity of isofrequency bands in both fields. An increase of ipsilateral leads from -2.5 to 10 ms resulted in a gradual decrease of the amplitude of the excitatory responses. A strong inhibition was observed in field DC and the ventral portion of field A. These results show the different spatiotemporal representation of IID and ITD sensitivities in AC. However, the ipsilateral lead inducing a large inhibition was much longer than the time difference (80 micros) calculated from the interaural distance of the guinea pig. This indicates that the longer binaural inhibition observed in AC would have a different functional significance from that of the neural system of ITD detection in the guinea pig.

Acoustic Stimulation↗

PubMed1999

Percutaneous transluminal coronary angioplasty, alone or in combination with urokinase therapy, during acute myocardial infarction.

To investigate the effect of pre-treatment of a thrombus with a low dose of urokinase on establishing patency in a persistent infarct-related artery (IRA) during direct percutaneous coronary angioplasty (PTCA), the frequency of acute restenosis during direct PTCA, alone, or in combination with the intracoronary administration of urokinase, was examined in a consecutive nonrandomized series of patients with acute myocardial infarction (AMI). Two hundred and seventy-two successful PTCA patients (residual stenosis <50%) were divided into 2 groups: 88 patients received pre-treatment with intracoronary urokinase following PTCA (combination group); 184 received only direct PTCA without thrombolytic therapy (PTCA group). In the present study, after achievement of a residual stenosis of less than 50%, IRA was visualized every 15 min to assess the frequency of acute restenosis, which was defined as an acute progression of IRA with more than 75% restenosis after initially successful PTCA. In the patients with a large coronary thrombus, the frequency (times) of acute restenosis was significantly lower in the combination group than in the PTCA group (0.98+/-0.19 vs 2.92+/-0.32, p<0.0001). On the other hand, in the patients with a small coronary thrombus, the frequency of acute restenosis showed no difference in either group. The present study indicates that in patients with AMI, PTCA combined with pre-treatment of a low dose of urokinase is much more effective than PTCA alone, especially for those patients who have a large coronary thrombus.

Angioplasty, Balloon, Coronary↗