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Takashi Kanda

Publications and source records attributed to Takashi Kanda.

At least 19 recordsLinked to original sources
PubMed2026

ALID score for treatment-effect heterogeneity of adjunctive low-voltage area ablation in persistent atrial fibrillation: A post hoc analysis of SUPPRESS-AF.

BACKGROUND: In persistent atrial fibrillation (AF), the incremental benefit of adjunctive low-voltage area (LVA) ablation beyond pulmonary vein isolation (PVI) remains inconsistent. OBJECTIVE: To examine whether a simple clinical score characterizes treatment-effect heterogeneity of adjunctive LVA ablation among patients with mapped LVA&#xa0;>&#xa0;5&#xa0;cm2 and to perform an exploratory supportive analysis in an independent randomized cohort. METHODS: In this post-hoc analysis of SUPPRESS-AF, which included patients with persistent AF and mapped LVA&#xa0;>&#xa0;5&#xa0;cm2 after PVI, four variables-age&#xa0;&#x2265;&#xa0;75&#xa0;years, left atrial diameter&#xa0;>&#xa0;44&#xa0;mm, estimated glomerular filtration rate&#xa0;<&#xa0;60&#xa0;mL/min/1.73&#xa0;m2, and absence of diabetes-were combined into the ALID score (0-4). Patients were stratified into low (0-1), intermediate (2), and high (3-4) score groups. Because EARNEST-PVI did not use LVA-guided ablation or select patients based on mapped LVA, it was analyzed as an exploratory supportive cohort rather than as an external validation cohort. RESULTS: In SUPPRESS-AF (n&#xa0;=&#xa0;336), a significant treatment-by-score interaction was observed (P&#xa0;<&#xa0;0.001). Adjunctive LVA ablation was associated with increased recurrence in the low-score stratum (HR 3.92; 95% CI 1.50-10.20) and reduced recurrence in the high-score stratum (HR 0.48; 95% CI 0.26-0.86). In EARNEST-PVI (n&#xa0;=&#xa0;494), a qualitatively similar interaction pattern was observed for additional ablation beyond PVI (interaction P&#xa0;=&#xa0;0.029), although the ablation strategy differed from LVA-guided ablation. CONCLUSIONS: Among patients with persistent AF and mapped LVA >5&#xa0;cm2, the ALID score identified heterogeneity in response to adjunctive LVA ablation. These hypothesis-generating findings require prospective validation before clinical implementation.

Humans↗
PubMed2006

Long-term outcome of infants with twin-to-twin transfusion syndrome.

OBJECTIVE: To clarify the long-term neurodevelopmental outcome of twin-to-twin transfusion syndrome (TTTS) survivors. METHODS: From January 1994 to December 2003, 33 newborns with TTTS who were derived from 18 monochorionic twin gestations were enrolled for the study. The development and growth at 3 or 6 years of age were compared between TTTS survivors and weight-matched singleton controls. RESULTS: The mortality in TTTS (8/33: 24%) was significantly higher than that of the controls (7/80: 9%). Of all 12 TTTS patients who were diagnosed before 25 weeks and born before 28 weeks of gestation, in 10 (83%) it led to neonatal or intrauterine death. The morbidity of cerebral palsy, epilepsy, and mental retardation did not differ between TTTS and control patients. The morbidity and severity of neurological deficits at school age were similar in both groups. No growth parameters at 3 or 6 years of age differed between TTTS and controls. CONCLUSIONS: Morbidity, growth and development of TTTS survivors attained comparable levels of weight-matched controls, despite the higher neonatal mortality. These results suggest that the early management of TTTS is critical for refining the total outcome of the affected twins.

Child Development↗
PubMed2006

Preparation of highly dispersed core/shell-type titania nanocapsules containing a single Ag nanoparticle.

Core/shell-type titania nanocapsules containing a single Ag nanoparticle were prepared. Ag nanoparticles were prepared using the reduction of silver nitrate with hydrazine in the presence of cetyltrimethylammonium bromide (CTAB) as protective agent. The sol-gel reaction of titanium tetraisopropoxide (TTIP) was used to prepare core/shell-type titania nanocapsules with CTAB-coated Ag nanoparticles as the core. TEM observations revealed that the size of the core (Ag particle) and the thickness of the shell (titania) of the core/shell particles obtained are about 10 nm and 5-10 nm, respectively. In addition, the nanocapsules were found to be dispersed in the medium as individual particles without aggregation. Moreover, titania coating caused the surface plasmon absorption of Ag nanoparticles to shift toward the longer wavelength side.

Journal Article↗
PubMed2006

T cell gene expression profiling identifies distinct subgroups of Japanese multiple sclerosis patients.

To clarify the molecular background underlying the heterogeneity of multiple sclerosis (MS), we characterized the gene expression profile of peripheral blood CD3+ T cells isolated from MS and healthy control (CN) subjects by using a cDNA microarray. Among 1258 cDNAs on the array, 286 genes were expressed differentially between 72 untreated Japanese MS patients and 22 age- and sex-matched CN subjects. When this set was used as a discriminator for hierarchical clustering analysis, it identified four distinct subgroups of MS patients and five gene clusters differentially expressed among the subgroups. One of these gene clusters was overexpressed in MS versus CN, and particularly enhanced in the clinically most active subgroup of MS. After 46 of the MS patients were treated with interferon-beta (IFNbeta-1b) for two years, IFNbeta responders were clustered in two of the four MS subgroups. Furthermore, the IFNbeta responders differed from nonresponders in the kinetics of IFN-responsive genes at 3 and 6 months after starting IFNbeta treatment. These results suggest that T-cell gene expression profiling is valuable to identify distinct subgroups of MS associated with differential disease activity and therapeutic response to IFNbeta.

Adjuvants, Immunologic↗
PubMed2005

In vivo delivery of small interfering RNA targeting brain capillary endothelial cells.

Brain capillary endothelial cells (BCECs) play an important role in blood-brain barrier (BBB) functions and pathophysiologic mechanisms in brain ischemia and inflammation. We try to suppress gene expression in BCECs by intravenous application of small interfering RNA (siRNA). After injection of large dose siRNA with hydrodynamic technique to mouse, suppression of endogenous protein and the BBB function of BCECs was investigated. The brain-to-blood transport function of organic anion transporter 3 (OAT3) that expressed in BCECs was evaluated by Brain Efflux Index method in mouse. The siRNA could be delivered to BCECs and efficiently inhibited endogenously expressed protein of BCECs. The suppression effect of siRNA to OAT3 is enough to reduce the brain-to-blood transport of OAT3 substrate, benzylpenicillin at BBB. The in vivo siRNA-silencing method with hydrodynamic technique may be useful for the study of BBB function and gene therapy targeting BCECs.

Animals↗
PubMed2005

Microarray analysis identifies an aberrant expression of apoptosis and DNA damage-regulatory genes in multiple sclerosis.

To clarify the molecular mechanisms underlying multiple sclerosis (MS)-promoting autoimmune process, we have investigated a comprehensive gene expression profile of T cell and non-T cell fractions of peripheral blood mononuclear cells (PBMC) isolated from 72 MS patients and 22 age- and sex-matched healthy control (CN) subjects by using a cDNA microarray. Among 1258 genes examined, 173 genes in T cells and 50 genes in non-T cells were expressed differentially between MS and CN groups. Downregulated genes greatly outnumbered upregulated genes in MS. More than 80% of the top 30 most significant genes were categorized into apoptosis signaling-related genes of both proapoptotic and antiapoptotic classes. They included upregulation in MS of orphan nuclear receptor Nurr1 (NR4A2), receptor-interacting serine/threonine kinase 2 (RIPK2), and silencer of death domains (SODD), and downregulation in MS of TNF-related apoptosis-inducing ligand (TRAIL), B-cell CLL/lymphoma 2 (BCL2), and death-associated protein 6 (DAXX). Furthermore, a set of the genes involved in DNA repair, replication, and chromatin remodeling was downregulated in MS. These results suggest that MS lymphocytes show a complex pattern of gene regulation that represents a counterbalance between promoting and preventing apoptosis and DNA damage of lymphocytes.

Adult↗
PubMed2005

Selective gene silencing of rat ATP-binding cassette G2 transporter in an in vitro blood-brain barrier model by short interfering RNA.

The aim of the present study was to specifically silence the rat ATP-binding cassette transporter G2 (rABCG2) gene in brain capillary endothelial cells by transfection of short interfering RNA (siRNA). Four different siRNAs designed to target rABCG2 were each transfected into HEK293 cells with myc-tagged rABCG2 cDNA. Quantitative real-time PCR and western blot analyses revealed that three of the siRNAs were able to reduce exogenous rABCG2 mRNA and protein levels in HEK293 cells. Moreover, rABCG2-mediated mitoxantrone efflux transport was suppressed by the introduction of these three siRNAs into HEK293 cells. In contrast, the other siRNA and non-specific control siRNA did not significantly affect the mRNA expression, the protein level or the transport activity. Endogenous rABCG2 mRNA and protein expression in a conditionally immortalized rat brain capillary endothelial cell line (TR-BBB13) was suppressed by the most potent siRNA among the four siRNAs tested. Furthermore, this siRNA did not affect the mRNA levels of other ABC transporters, such as ABCB1, ABCC1 and ABCG1, and the protein level of ABCB1 in TR-BBB13 cells, suggesting that it can selectively silence rABCG2 at the blood-brain barrier. This should be a useful and novel strategy for clarifying the contribution of rABCG2 to brain-to-blood transport of substrate drugs and endogenous compounds across the blood-brain barrier.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed2004

Glycosphingolipid composition of primary cultured human brain microvascular endothelial cells.

Glycosphingolipid (GSL) antigens have been considered to be involved in the pathogenesis of autoimmune neurologic disorders including multiple sclerosis. To establish the GSL pattern specific for endothelial cells forming blood-brain barrier (BBB), we established a method to yield sufficient quantities of highly purified human brain microvascular endothelial cells (HBMECs) and compared their GSL composition to that of human umbilical cord vein endothelial cells (HUVECs), as the representative of endothelial cells not forming BBB. The major gangliosides were GM3 and sialyl paragloboside (LM1), and the major neutral GSLs were lactosylceramide (LacCer), globotriaosylceramide (Gb3), and globoside (Gb4). Trace amounts of GM1, GD1a, GD1b, GT1b, and sulfoglucuronosyl paragloboside (SGPG) could be detected by the high performance thin layer chromatography-overlay method. SGPG was detected only at a nonconfluent state in an amount almost 1/30 that of in nonconfluent HUVECs. Conversely, GM3 and LM1 increased significantly after confluency. The amount of Gb3 in HBMECs was almost as twice that in HUVECs. The significance of these differences in GSL content between HBMECs and HUVECs and between confluent and nonconfluent states is obscure. It might be related, however, to the defense mechanism at the BBB and to the susceptibility of the central nervous system in some disorders that target cell surface GSL, such as hemolytic uremic syndrome.

Aged↗
PubMed2003

Sera from Guillain-Barré patients enhance leakage in blood-nerve barrier model.

BACKGROUND: In Guillain-Barré syndrome (GBS), the destruction or malfunction of blood-nerve barrier (BNB) has been considered to be the beginning of the disease process. It is unclear whether sera from patients with GBS can open the BNB, and which component of patient sera is most important in the dysregulation of the BNB. METHODS: The authors evaluated the effect of sera from patients with GBS on permeability of an in vitro BNB model using bovine endoneurial microvascular endothelial cells (PnMEC) cultured on the luminal side of a collagen-coated culture insert (pore size: 0.4 micro m). RESULTS: PnMEC monolayers challenged by GBS sera showed significantly lower transendothelial electrical resistance and higher clearance of [carboxyl-(14)C]-inulin with or without complement. Sera with anti-GM1 antibody showed greater loosening of the barrier than others. This effect decreased significantly after incubation with pure GM1 antigen, suggesting the importance of anti-GM1 antibody in BNB dysregulation. Serial analyses of [carboxyl-(14)C]-inulin clearance in four patients disclosed a favorable effect of plasmapheresis in restoring BNB function in some cases. CONCLUSIONS: The authors found an unfavorable effect of sera from patients with GBS on BNB function, supporting involvement of humoral factors causing BNB derangement in the acute stage. Serial evaluation of permeability change using the authors' in vitro system might be useful for the clinical assessment of BNB derangement in individual patients.

Adult↗
PubMed2003

Microarray analysis identifies interferon beta-regulated genes in multiple sclerosis.

The molecular mechanisms for the interferon beta (IFNbeta) treatment of multiple sclerosis (MS) remain to be characterized. Using cDNA microarray technology, we have compared the gene expression profile of T and non-T cells derived from relapsing-remitting MS before and after treatment with IFNbeta-1b. IFNbeta treatment significantly altered expression of 21 genes out of 1263 at 3 and 6 months after treatment. These genes included nine with IFN-responsive promoter elements. Whereas there was no change in Th1 or Th2 marker genes, some of the changes were unexpected but coincided with the beneficial effect of IFNbeta in MS.

Adult↗
PubMed2003

[Bilateral medial medullary infarction presented with monoplegia of the lower limb, followed by paraplegia and finally by tetraplegia].

A 69-year-old Japanese man suddenly developed monoplegia of left lower extremity, followed by paraplegia and finally by tetraplegia. MRI revealed an infarction in bilateral medial medulla extending from the cervicomedullary junction up to the upper limit of the medulla. Both hypoglossal nerve palsy and sensory disturbance were absent. At the pyramidal decussation, fibers to the lower extremities cross caudal to the fibers going to the upper extremities, therefore right below the decussation, fibers to the lower extremities run medial side of the fibers to the upper extremities, but later the former run lateral side of the latter. In this patient, the authors considered that the lesion initially damaged the pyramidal decussation at a slightly lower level, involving the tract to left lower extremity, and then extended to right lower extremity, to the left upper extremity, finally to the right upper extremity. Bilateral medial medullary infarction must be considered in the clinical course seen as in this patient.

Cerebral Infarction↗
PubMed2003

[Pneumatosis intestinalis in a patient of myasthenia gravis treated with high-dose corticosteroid].

We report a patient who developed persistent and severe diarrhea in the course of high-dose corticosteroid therapy for myasthenia gravis (MG). The patient, a 37-year-old woman, developed diplopia, ptosis, and muscle weakness with fatigability. She was admitted to our hospital and was diagnosed as having MG. Five months after thymectomy and oral corticosteroid administration, she developed abdominal pain and severe diarrhea. Abdominal X-ray, showed extensive pericolic gas accumulation surrounding the ascending and transverse colon. She was diagnosed as having pneumatosis intestinalis (PI). Hyperbaric therapy was not effective. Symptoms began to improve gradually when the dose of prednisolone was reduced. PI is a rare condition characterized by gas-filled cysts or linear gas in the bowel wall caused by a variety of disorders and drugs such as necrotizing colitis, obstructive pulmonary diseases, and immunosuppressants. In the present case, PI appeared to be induced by corticosteroid therapy. To our knowledge, MG complicated by PI is unusual, but this rare case highlights the importance of taking it into consideration during steroid therapy for MG.

Adult↗
PubMed2003

[Blood-brain barrier in multiple sclerosis: mechanisms of its breakdown and repair].

The blood-brain barrier(BBB) restricts exchanges of soluble factors and cells between the blood and brain, thus playing a crucial role in maintenance of cerebral homeostasis. In multiple sclerosis(MS), disruption of the BBB is the initial key step in the development of inflammatory lesions. BBB impairment may occur before the formation of demyelinative foci or T cell infiltration around small vessels; however, once the BBB breaks, massive infiltration of T cells, augmented expression of adhesion molecules on endothelial cell surface, and leakage of inflammatory cytokines and antibodies will aggravate the MS lesions. Although glucocorticoids and type 1 interferons are now widely used and are known to decrease BBB permeability additively, the development of novel therapeutic strategy focusing on the repairment of BBB integrity should be awaited.

Adrenal Cortex Hormones↗