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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Blalock-Taussig shunt and pulmonary artery angioplasty for isolated unilateral absence of the right pulmonary artery; report of a case].

A 7-month-old girl was referred to us for further examination of absence of the right pulmonary artery. She had no symptom at that time. Diagnosis was made by chest computed tomography (CT) and cardiac catheterization. Though the size of the right pulmonary artery was not apparent, right pulmonary vein wedge angiography revealed the distal portion of right pulmonary artery sufficient for surgical repair. But the distance between the pulmonary trunk and right pulmonary artery was too far to perform direct anastomosis, and some systemic collaterals had already been recognized. Pulmonary vasculature was also not inadequate. Therefore we planned a palliative procedure. At the age of 7 months, right modified Blalock-Tausig shunt using 5mm expand-polytetrafluoroethylene (ePTFE) tube and angioplasty of the distal portion of right pulmonary artery using autologous pericardium roll with Dacron mesh was performed. Postoperative course was uneventful. She has been followed up for 6 months after the palliation. In the near future the completion of the definitive repair will be considered.

Anastomosis, Surgical↗
PubMed2005

[Jatene procedure with arch repair; usefulness of rapid two-stage repair].

Four cases of Jatene procedure with arch repair were performed since 2000 in our department. Two-stage repair was used in all cases and the extended end-to-end anastomosis and pulmonary artery banding (PAB) were performed in 3 cases as the initial repair. In a recent case of TGA type I with coarctation of the aorta (CoA), only subclavian flap aortoplasty was performed when he was 6-day-old and patent ductus arteriosus (PDA) was preserved and rapid two-stage Jatene procedure was performed when he was 8-day-old. There was no hospital or late death, or reoperation. The results of the two-stage Jatene procedure with arch repair was good and safe. Rapid two-stage repair was thought to be a useful choice especially for TGA type I with arch anomaly.

Aorta, Thoracic↗
PubMed2004

ARPES on Na0.6CoO2: Fermi surface and unusual band dispersion.

The electronic structure of single crystals Na0.6CoO2, which are closely related to the superconducting Na0.3CoO2.yH(2)O (T(c) approximately 5 K), is studied by angle-resolved photoelectron spectroscopy. While the measured Fermi surface (FS) is consistent with the large FS enclosing the Gamma point from the band theory, the predicted small FS pockets near the K points are absent. In addition, the band dispersion is found to be highly renormalized, and anisotropic along the two principal axes (Gamma-K, Gamma-M). Our measurements also indicate that an extended flatband is formed slightly above E(F) along Gamma-K.

Journal Article↗
PubMed2004

Experimental evidence for the p-d hybridization in the Cd-Ca quasicrystal: origin of the pseudogap.

Ca 2p-3d resonant photoemission spectroscopy of a Cd6Ca crystalline approximant unambiguously demonstrates that the low-lying unoccupied 3d levels of calcium are lowered below the Fermi energy by the formation of the approximant, as suggested from electronic structure calculations [Phys. Rev. Lett. 87, 206408 (2001)]]. Moreover, the Ca 3d partial density of states (DOS) obtained near the Fermi energy is in reasonable agreement with theoretical Ca 3d DOS. These results verify the unconventional picture that the origin of the pseudogap in the Cd-based quasicrystals is due to hybridization of the Ca 3d band with the Cd 5p band.

Journal Article↗
PubMed2004

Nonspecific immune response of rainbow trout (Oncorhynchus mykiss Walbaum) in relation to different status of vitamin E and highly unsaturated fatty acids.

This study was designed to examine the effects of dietary vitamin E (VE) on modulation of immune responses when supplied with two levels of n-3 highly unsaturated fatty acids (n-3 HUFA) in rainbow trout, Oncorhynchus mykiss. Six semipurified diets were prepared containing three levels of dietary VE (0, 100 or 1000 mg alpha-tocopheryl acetate kg(-1) diet) and n-3 HUFA either at 20 or 48% of dietary lipid provided from fish oil or docosahexaenoic acid (DHA) concentrated fish oil respectively. The diets were fed to rainbow trout (100 g initial mean weight) for 15 weeks. The VE, vitamin C (VC) content in plasma and tissues and the nonspecific immune responses, both humoral (alternative complement activity, total immunoglobulin) and cellular (phagocytosis, nonspecific cytotoxicity) were examined. VE contents in the kidney reflected the dietary input but were lower in fish fed 48% n-3 HUFA diets, and could have impaired some of immune responses compared to fish fed 20% n-3 HUFA. VC contents in kidney followed the same pattern as VE. Both humoral and cellular immune functions deteriorated in fish fed VE deficient diets whereas improvement in most of the parameters corresponded to its supplementation. However, the higher dose of dietary VE did not substantially enhance the responses assayed compared to the 100 mg dose. Besides clearly indicating the role of VE in maintaining the immune functions in fish in relation to dietary n-3 HUFA, this study has revealed that optimum health benefits could be achieved when VE is maintained slightly above the levels generally recommended for normal growth.

Animals↗
PubMed2004

Cdx1 induced intestinal metaplasia in the transgenic mouse stomach: comparative study with Cdx2 transgenic mice.

BACKGROUND AND AIMS: Gastric intestinal metaplasia, which is mainly induced by Helicobacter pylori infection, is thought to be a precancerous lesion of gastric adenocarcinoma. Intestinal metaplastic mucosa expresses intestine specific homeobox genes, Cdx1 and Cdx2, in the human gastric mucosa. We and others have reported that ectopic expression of Cdx2 in the gastric epithelium generates intestinal metaplasia in the transgenic mouse model. METHODS: To clarify the differences in the roles of Cdx1 and Cdx2 in intestinal metaplasia, we generated transgenic mice expressing Cdx1 in the gastric mucosa and compared Cdx1 induced gastric mucosal morphological changes with Cdx2 induced intestinal metaplasia. RESULTS: The gastric mucosa in Cdx1 transgenic mice was completely replaced by intestinal metaplastic mucosa, consisting of all four intestinal epithelial cell types: absorptive enterocytes, goblet, enteroendocrine, and Paneth cells. Paneth cells, which were not recognised in Cdx2 transgenic mice, were in the upper portion of the intestinal metaplastic mucosa. Pseudopyloric gland metaplasia, which was induced in Cdx2 transgenic mice, was not recognised in Cdx1 transgenic mice. Proliferating cell nuclear antigen (PCNA) positive cells were diffusely scattered in Cdx1 induced intestinal metaplastic mucosa while PCNA positive cells in Cdx2 induced intestinal metaplastic mucosa were in the base of the metaplastic mucosa. Intestinal metaplastic mucosa of Cdx1 transgenic mouse stomach was significantly thicker than that of wild-type or Cdx2 transgenic mouse stomach. CONCLUSIONS: We have confirmed that Cdx1 induced gastric intestinal metaplasia but that it differed from Cdx2 induced intestinal metaplasia in differentiation, structure, and proliferation.

Animals↗
PubMed2004

Intracytoplasmic sperm injection. Accomplishments and qualms.

AIM: Intracytoplasmic sperm injection (ICSI) is now the preferred technique for treatment of male factor infertility and many children have been born worldwide. However, concerns about the risk of transmitting genetic defects and development of ICSI children have been raised. We report clinical outcome of ICSI in Cornell University and results of screening for genetic defects in ICSI parents and their children. METHODS: Pregnancy and obstetrical outcomes as well as congenital malformations were analyzed. Chromosomal karyotyping and Yq deletion assessments were performed on blood samples. In addition, medical and developmental outcome were assessed in 3 and 5 year old ICSI children. RESULTS: We have performed 8 575 ICSI cycles with ejaculated spermatozoa that resulted in a 75.4% fertilization and a 42.8% clinical pregnancy rates while for surgically retrieved specimen resulted in 66%, 48.8% respectively. The incidence of Y deletion was within the expected range for an infertile population, with identical deletions transmitted to the male offspring. There were no differences in cognitive, motor and behavioral development observed between ICSI children and these conceived naturally. CONCLUSION: The large majority of infertile men were treatable by ICSI, which resulted in the transmission of a specific abnormality but did not enhance the incidence of de novo deletions. There is no indication that ICSI children develop more congenital defects or express a lower psychomotor development that children conceived naturally. Nonetheless, genetic screening and counseling of couples undergoing ICSI would seem to be appropriate.

Adult↗
PubMed2004

[Successful staged repair of a symptomatic neonate of tetralogy of Fallot with severe absent pulmonary valve syndrome].

Tetralogy of Fallot with absent pulmonary valve has been classified to a few groups. The most severe one is characterized by symptomatic onset immediately after birth. The others are no or slightly symptomatic at least during their neonatal period. In a severely symptomatic 12-day-old neonate of tetralogy of Fallot with absent pulmonary valve who had required intubation immediately after birth, tight pulmonary banding and left side modified Blalock-Taussig shunt were performed on emergency basis. Consequently, prior massive pulmonary regurgitation was decreased significantly. Forty-five days after this first stage operation, he weaned from respiratory management. At 1-year-old, radical repair based on conotruncal repair, which consisted of patch closure of ventricular septal defect preserving the tricuspid septal leaflet function, resection of anterior wall of enlarged left pulmonary artery, and right ventricular outflow tract reconstruction using autologous tissue and a pericardial patch was performed. Bicuspid pulmonary valve, posterior one of procured autologous pulmonary wall and anterior one of polytetrafluoroethylene (PTFE) respectively, was created to minimize deterioration of the pulmonary insufficiency. Although postoperative cardiac function was kept feasible showing his central venous pressure of 7 mmHg in the main, postoperative general course was eventful especially regarding the respiratory function. The patient was weaned from the prolonged ventilator management 5 months after this radical repair eventually. Generally, to diminish the massive pulmonary regurgitation in early lifetime period could reduce a progressive airway obstruction and minimize pulmonary tissue damage. However, even after the total correction in this case, considerable peripheral segmental pulmonary obstructive lesions were persistent according to the perfusion lung scanning with 99mTc macroaggregated albumin and 99mTechnegas ventilation lung scanning studies. This persistent, supposed to be innate, pulmonary obstructive lesions might prevent ordinal recovery after cardiac radical repair for this most severe subtype of absent pulmonary valve syndrome.

Blood Vessel Prosthesis Implantation↗
PubMed2004

[Valvuloplasty for mitral regurgitation immediately following Kawasaki disease without abnormal coronary arteries lesion; report of a case].

It is not uncommon that valve disease is complicated with Kawasaki disease (KD). However, it is rare to show normal coronary arteries simultaneously. We experienced a case of valvuloplasty towards the mitral regurgitation (MR) followed immediately after KD showing normal coronary arteries. A 3 year-old-female, with a diagnosis of KD at 4 months after birth, was referred to our hospital 5 months after birth. The echocardiography detected a moderate MR. The preoperative catheterization at 2.5 years old showed grade III MR, enlargement of left atrium and left ventricle, pulmonary capillary wedge pressure (PCWP) = 12 mmHg, left ventricular ejection fraction (LVEF) = 675, and normal coronary arteries. Pulmonary hypertention was not revealed. The operative findings showed mitral valve prolapse due to the elongation of the chordae of the anterior leaflet. She underwent artificial chordal reconstruction using expanded polytetrafluoroethylene sutures and mitral annuloplasty by Kay-Reed method. The postoperative course was uneventful, and she was discharged on postoperative day 19.

Artificial Organs↗
PubMed2003

Energetic protons from a few-micron metallic foil evaporated by an intense laser pulse.

With detailed experimental studies and hydrodynamics and particle-in-cell simulations we investigate the role of the prepulse in laser proton acceleration. The prepulse or pedestal (amplified spontaneous emission) can completely evaporate the irradiated region of a sufficiently thin foil; therefore, the main part of the laser pulse interacts with an underdense plasma. The multiparametric particle-in-cell simulations demonstrate that the main pulse generates the quasistatic magnetic field, which in its turn produces the long-lived charge separation electrostatic field, accelerating the ions.

Journal Article↗
PubMed2003

Resonant double excitation observed in the near-threshold evolution of the photoexcited F K alpha satellite intensity in NaF.

We present a precise measurement of the photoexcited F K alpha satellite intensity's evolution for NaF from [1s2p] double excitation threshold to saturation. A direct comparison between the observed evolution and the x-ray absorption spectrum was successfully made, and the contribution of multielectron transitions to the absorption spectrum was clearly resolved for the first time. A resonance-like feature observed in the near-threshold evolution is attributed to the [1s2p]3p(2) resonant double excitation as confirmed by calculations.

Journal Article↗
PubMed2003

Effects of CO2 concentration and light intensity on photosynthesis of a rootless submerged plant, Ceratophyllum demersum L., used for aquatic food production in bioregenerative life support systems.

In addition to green microalgae, aquatic higher plants are likely to play an important role in aquatic food production modules in bioregenerative systems for producing feed for fish, converting CO2 to O2 and remedying water quality. In the present study, the effects of culture conditions on the net photosynthetic rate of a rootless submerged plant, Ceratophyllum demersum L., was investigated to determine the optimum culture conditions for maximal function of plants in food production modules including both aquatic plant culture and fish culture systems. The net photosynthetic rate in plants was determined by the increase in dissolved O2 concentrations in a closed vessel containing a plantlet and water. The water in the vessel was aerated sufficiently with a gas containing a known concentration of CO2 gas mixed with N2 gas before closing the vessel. The CO2 concentrations in the aerating gas ranged from 0.3 to 10 mmol mol-1. Photosynthetic photon flux density (PPFD) in the vessel ranged from 0 (dark) to 1.0 mmol m-2 s-1, which was controlled with a metal halide lamp. Temperature was kept at 28 degrees C. The net photosynthetic rate increased with increasing PPFD levels and was saturated at 0.2 and 0.5 mmol m-2 s-1 PPFD under CO2 levels of 1.0 and 3.0 mmol mol-1, respectively. The net photosynthetic rate increased with increasing CO2 levels from 0.3 to 3.0 mmol mol-1 showing the maximum value, 75 nmol O2 gDW-1 s-1, at 2-3 mmol mol-1 CO2 and gradually decreased with increasing CO2 levels from 3.0 to 10 mmol mol-1. The results demonstrate that C. demersum could be an efficient CO2 to O2 converter under a 2.0 mmol mol-1 CO2 level and relatively low PPFD levels in aquatic food production modules.

Animals↗
PubMed2003

Application of intracytoplasmic sperm injection in assisted reproductive technologies.

Intracytoplasmic sperm injection (ICSI) entails the mechanical insertion of a chosen spermatozoon directly into the cytoplasm of an oocyte. Due to the consistent fertilization and pregnancy outcome, ICSI is routinely used to treat azoospermic patients where spermatozoa are retrieved by epididymal aspiration or testicular biopsy. Since male subfertility has been associated with a higher incidence of genomic defects, ranging from numerical chromosomal abnormalities to Yq microdeletions, concerns have been raised as to the risk of transmitting genetic defects to the offspring. Screening for such defects can provide invaluable information for appropriate counselling prior to ICSI treatment. In order to address these concerns, a follow-up of the children born after ICSI treatment was conducted.

Adult↗
PubMed2003

Reciprocal altered expression of T-cadherin and P-cadherin in psoriasis vulgaris.

BACKGROUND: The most characteristic change in psoriasis vulgaris is markedly increased, persistent keratinocyte proliferation. The underlying mechanism of excessive epidermal growth is controversial. We previously found and reported that T-cadherin was expressed in keratinocytes and confined to the basal layer of mouse and human skin. Invasive cutaneous squamous cell carcinoma showed a loss of T-cadherin expression. Another study showed that T-cadherin was a negative growth regulator of epidermal growth factor in T-cadherin transfectant neuroblastoma cells. OBJECTIVES: To obtain insight into the role of T-cadherin in keratinocyte proliferation and to investigate further the pathogenesis of psoriasis vulgaris, we examined the expression of T-cadherin, as well as E- and P-cadherin, in psoriasis vulgaris. METHODS: Four untreated active psoriatic skin samples from psoriasis vulgaris patients and four normal human skin samples from plastic surgery were collected, cryosectioned and immunohistochemically stained by antihuman T-, P- and E-cadherin antibodies. Further, the immunofluorescence intensities of T- and P-cadherin on the basal layer of the epidermis were quantitatively measured by the histogram function of LSM 510 software installed in a Zeiss laser scanning confocal microscope. The data were statistically analysed by Student's t-test. RESULTS: It was observed that T-cadherin was weakly and discontinuously expressed on the basal layer of psoriatic skin, while it was intensively expressed on all basal keratinocytes in normal human skin. In contrast, P-cadherin was strongly expressed throughout the entire epidermal layer in psoriatic skin samples, although its expression is restricted to the basal cell layer in normal human skin. There were no obvious differences in E-cadherin expression between normal human skin and psoriatic skin. Statistical analyses showed that the immunofluorescence intensity of T-cadherin in the basal cell layer of psoriatic skin (35 +/- 9.08) was significantly decreased compared with that in normal human skin (131.75 +/- 3.49, P = 2.46 x 10(-6)). There was a significant increase (P = 0.00139) in the immunofluorescence intensity of P-cadherin in the basal layer of psoriatic skin (68.25 +/- 12.13) compared with normal human skin (26 +/- 4.90). CONCLUSIONS: The present study demonstrates that there is downregulation of T-cadherin expression and upregulation of P-cadherin expression in psoriatic skin, which are considered to be involved in the hyperproliferation of keratinocytes in psoriasis vulgaris.

Cadherins↗
PubMed2003

Characteristics of lactoferrin receptor in bovine intestine: higher binding activity to the epithelium overlying Peyer's patches.

Several lines of evidence have recently demonstrated the occurrence of specific lactoferrin (Lf) receptors in different cells. We report here, for the first time, the characteristics of binding, and distribution of Lf receptors in the bovine intestinal tract with special emphasis on the epithelium overlying Peyer's patches (EOPP). Brush-border membrane vesicles (BBMV) were prepared from the mucosa of duodenum, jejunum, ileum, colon, EOPP in jejunum and EOPP in ileum. Receptor binding assays were carried out using 125I-labelled bovine Lf. Specific and saturable Lf receptors were found in BBMV of all the intestinal segments examined. Non-linear regression and Scatchard plot analyses clearly revealed that EOPP had the highest binding maximal (Bmax), and lowest in colon. The maximum dissociation constant (Kd) 3.74 microm was in the ileum. We found that bovine transferrin competed with Lf for the same binding site of receptors. In contrast, no binding of bovine serum albumin occurred. It was concluded that Lf receptors in the mucosal lining are attributable to mediate multifunctional activities of Lf in the gut, especially in the EOPP.

Animals↗
PubMed2003

Impaired pancreatic endocrine and exocrine responses in growth-retarded piglets.

The alteration of pancreatic endocrine and exocrine secretory responses induced by secretagogues and neural input was investigated in post-weaning growth-retarded (GR) piglets. Blood and pancreatic juice were collected from these animals (6-8-weeks old). Plasma insulin and pancreatic digestive enzymes induced by nutrients, drugs and vagal stimulation were measured biochemically. The pancreas was inspected by immunohistochemical analysis. In GR piglets, the plasma glucose and insulin concentrations at the resting state were very low, and the secretory response was also markedly reduced, with maximum inhibition of 90% by glucose administration and 83% by arginine administration. The insulin secretion was not increased by 2-deoxy-D-glucose administration in GR piglets. The pancreatic juice secretions induced by vagal stimulation and secretagogues in GR piglets were not different from those induced in the control piglets. However, amylase activity in the pancreatic juice and in the pancreas was significantly decreased in GR piglets, although trypsin and chymotrypsin activities were not different. In the immunohistochemical analysis, the numbers of islets and the staining degree for insulin antibody also declined in the pancreases of GR piglets. These results indicated the reduction of insulin and amylase secretions from the pancreas in GR piglets, suggesting that a dysfunction of pancreatic endocrine and exocrine secretion during growth after weaning may be an important factor in the induction of growth retardation in piglets.

Amylases↗
PubMed2003

Clinical evaluation of pioglitazone in patients with type 2 diabetes using alpha-glucosidase inhibitor and examination of its efficacy profile.

AIM: Pioglitazone is considered to reduce insulin resistance. This study was conducted to evaluate the efficacy, safety and clinical profile of pioglitazone in patients whose type 2 diabetes were poorly controlled with alpha-glucosidase inhibitor alone or alpha-glucosidase in combination with sulfonylurea. METHODS: Twenty patients with type 2 diabetes were treated with pioglitazone (30 mg q.d.) orally for 16 weeks. RESULTS: There were significant reductions in HbA1C, FPG and postprandial plasma glucose at week 16. As adverse events, oedema, hypoglycaemia-like reaction, increases in LDH, CPK, etc. were noted. There was no significant change in TNF-alpha. Leptin levels increased significantly at week 16 and were still increasing 4 weeks after the treatment. Per cent body fat was almost constant throughout the study period. When efficacy was classified by demographic variables, pioglitazone was found to be more effective in the subjects who had a higher postprandial 2-h plasma glucose level, leptin level or per cent body fat value. CONCLUSION: Pioglitazone was considered to be effective when used in patients whose type 2 diabetes were poorly controlled with alpha-glucosidase inhibitor alone or alpha-glucosidase in combination with sulfonylurea.

Adult↗