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Biomedical subjects

T Ito

Publications and source records attributed to T Ito.

At least 469 records · Page 26Linked to original sources
PubMed2000

Simultaneous intravascular two-dimensional plus Doppler ultrasound is useful for evaluation of postischemic vasodilatation: plasm NOx - levels determined by the Griess method may not reflect the extent of postischemic NO-induced vasodilatation.

Our objective was 1) to assess postischemic vasodilatation using simultaneous intravascular two-dimensional and Doppler ultrasound, and 2) to clarify whether plasma nitrite and nitrate (NOx-) levels change during postischemic vasodilatation. The vascular cross-sectional area (CSA) was evaluated in 18 mongrel dogs, and the average instantaneous peak velocity (APV) in the iliac arteries after the 5-min occlusion of blood flow was determined. Plasma NOx- levels were measured at the baseline, during the occlusion of blood flow, and 1.5, 3, and 10 min after recanalization. The %CSA significantly increased from 30 s to 7 min after the recanalization, and maximal vasodilatation was observed at 1.5 min after the recanalization (14.1 +/- 0.9 to 15.8 +/- 1.0 mm2, p< 0.0001 vs. baseline). Plasma NOx- levels were significantly reduced during the occlusion of blood flow and remained reduced at 1.5, 3, and 10 min after recanalization compared with the baseline values. We concluded that simultaneous intravascular two-dimensional and Doppler ultrasound is useful for assessment during postischemic vasodilatation, and that plasma NOx- levels assayed with the Griess reagent do not significantly increase, even when maximal vasodilatation is observed.

Animals↗
PubMed2000

Effects of orvus ES paste on canine spermatozoal longevity after freezing and thawing.

Because of weak resistance of canine sperm to freezing, an applicable method of preparing canine frozen semen has not yet been established. We added various concentrations of Orvus ES Paste (OEP) to egg yolk Tris-fructose citrate, and investigated its effectiveness on survival of spermatozoa. Addition of 0.5-1.0% OEP to the extender for freezing canine semen was effective in prolonging post-thaw survival of spermatozoa.

Animals↗
PubMed2000

Salmonella contamination in commercial layer feed in Japan.

A total of 4,418 samples of commercial layer feeds obtained in 1998 were investigated for the presence of salmonellae. A total of 146 strains of salmonellae which consisted of 32 serovars, including 20 strains of Salmonella Enteritidis, were isolated from 143 feed samples.

Animals↗
PubMed2000

Analysis of cytokine mRNA expression in pancreatic islets of nonobese diabetic mice.

Nonobese diabetic mice develop type 1 diabetes in an age-related and gender-dependent manner. Th1 (IFN-gamma and TNF-beta) and Th2 (IL-4 and IL-10) cytokine mRNA expression was analyzed in pancreatic islets isolated from female NOD mice with a high incidence of diabetes and male NOD mice with a low incidence of diabetes. The levels were measured at 5 time points from the onset of insulitis until the development of overt diabetes, using a semiquantitative reverse transcriptase PCR (RT-PCR) assay. IFN-gamma mRNA levels were significantly higher in the islets obtained from females than those of males, from 10 weeks of age. TNF-beta mRNA was expressed in both females and males between 5 and 15 weeks of age. However, TNF-beta mRNA levels were decreased in males at 20 weeks of age. In contrast, IL-4 mRNA levels were lower in females than in males. These results suggest that islet beta-cell destruction and diabetes in female NOD mice correlates with IFN-gamma and TNF-beta production in the islets, and that male NOD mice may be protected from autoimmune beta-cell destruction by down-regulation of these cytokines. Furthermore, our findings also suggest that insulitis and beta-cell destruction are independently regulated: TNF-beta is more important in forming and maintaining the insulitis, while IFN-gamma has a more important role in beta-cell destruction.

Animals↗
PubMed2000

Comparison of vectorcardiographic and 12-lead electrocardiographic detections of abnormalities in repolarization properties due to preexcitation in patients with Wolff-Parkinson-White syndrome: proposal of a novel concept of a "remodeling gradient".

Repolarization abnormalities after radiofrequency ablation in patients with manifest Wolff-Parkinson-White syndrome (WPW) have been attributed to cardiac memory of pre-existing changes in repolarization properties. We compared spatial ventricular gradient (VG) from vectorcardiograms with QRST values of 12-lead ECG in 41 patients with WPW (group A, manifest WPW due to left-sided accessory pathway (n = 20); group B, manifest WPW due to right-sided accessory pathway (n = 12); group C, concealed WPW (n = 9)) before and after ablation. Group N (n = 607) served as control. In groups A and B, the abnormalities of spatial VG and QRST values of 12-lead ECG that existed before and 1 day after ablation significantly decreased 1 week after ablation. In group C, spatial VG and QRST values of 12-lead ECG showed no significant changes. The diagnostic ability of spatial VG is almost equivalent to that of the QRST value of ECG in detecting repolarization abnormalities in patients with WPW before and after ablation. We propose a new concept of a "remodeling gradient" directing from the preexcited area to the opposite side of the ventricle as a result of preexcitation-induced electrical remodeling.

Adolescent↗
PubMed2000

Conformational effects on photophysical characteristics of C5-C5'-linked dihydrothymine dimers in solution.

Photophysical characteristics of N-substituted C5-C5'-linked dihydrothymine dimers (1a,b[meso], meso compounds of [5R,5'S]-bi-5,6-dihydrothymines; 1a,b[rac], racemic compounds of [5R,5'R]-bi-5,6-dihydrothymines and [5S,5'S]-bi-5,6-dihydrothymines) in aqueous solution with varying contents of less-polar aprotic solvent such as tetrahydrofuran or dioxane have been investigated by UV-absorption, and steady-state and time-resolved fluorescence spectroscopies. Among the C5-C5'-linked dimers, (5R,5'S)-bi-5,6-dihydro-1-methylthymine (1a[meso]) showed a red-shifted weak UV-absorption band at 270-350 nm and excimer fluorescence emission at lambda max = 370 nm with a quantum yield (phi F) of approximately 0.1 in phosphate buffer (pH < 10) at 293 K. Racemic compound of 5,6-dihydro-1-methylthymine dimer (1a[rac]), meso and racemic compounds of 5,6-dihydro-1,3-dimethylthymine dimers (1b[meso] and 1b[rac]) in phosphate buffer were nonfluorescent under similar conditions. The UV-absorption and fluorescence spectral characteristics of 1a[meso] in aqueous solution were interpreted in terms of intramolecular stacking interactions between the dihydropyrimidine chromophores leading to a preferential "closed-shell" conformation both in the ground state and the excited singlet state. In basic solutions at pH > pKa = 11.7, the fluorescence quantum yield of 1a[meso] decreased due to a dominant "open-shell" conformation resulting from the electrostatic repulsion between the deprotonated dihydrothymine chromophores of 1a[meso] in a dianion form.

Journal Article↗
PubMed2000

Acute disseminated encephalomyelitis developed after acute herpetic gingivostomatitis.

A child with acute disseminated encephalomyelitis (ADEM) developed after acute herpetic gingivostomatisis was described. Inspite of the improvement of his gingivostomatitis, his consciousness gradually deteriorated and he was admitted to Nakadori General Hospital. His consciousness level was drowsiness and increased bilateral patellar reflexes were shown. Because magnetic resonance imaging (MRI) T2-weighted scan showed areas of high signal intensity disseminated in superior portion of medulla oblongata, dorsal portion of pons, basal nuclei and thalamus, he was suspected as having ADEM. Anti-herpes simplex virus (HSV) 1 IgG and IgM antibodies elevated in both blood and cerebrospinal fluid. From these results, HSV1 infection was thought to be the preceding infection of ADEM. Methylprednisolone therapy (20 mg/kg daily) for 3 days, followed by prednisolone (2 mg/kg) was started, with an excellent response. In addition, administration of acyclovir was also continued, considering the complication of HSV encephalitis. MRI T2-weighted scan performed at 2 months later after the onset of ADEM revealed disappearance of the lesions. He was discharged without remaining disorders. It is difficult to distinguish between ADEM and HSV encephalitis because both of these diseases show various neurological symptoms. In our case, MRI was the most useful method for correct diagnosis of ADEM. We concluded that ADEM is important as a disease of central nervus system due to HSV1 infection, in addition to encephalitis.

Acute Disease↗
PubMed2000

Development of mouse dendritic cells from lineage-negative c-kit(low) pluripotent hemopoietic stem cells in vitro.

Dendritic cells (DCs) are essential for the presentation of antigens in the primary immune response. To examine the generation of DCs from hemopoietic stem cells in the bone marrow (BM), lineage-negative (Lin-)/CD71- bone marrow cells (BMCs) from C57BL/6 mice were separated into major histocompatibility complex (MHC) class Ihigh/ c-kit(low) and MHC class Ihigh/c-kit(low)(phenotypically c-kit-negative, but c-kit message only detected by reverse transcriptase-polymerase chain reaction) populations. A large number of cells with the morphological, phenotypical, and functional characteristics of DCs was generated from both c-kit(low) and c-kit(low) populations when cultured with a combination of cytokines (GM-CSF, tumor necrosis factor-a [TNF-a], interleukin 7 [IL-7], IL-3, stem cell factor [SCF], and flt3 ligand); the cytokine combination studies revealed that SCF and IL-3 in addition to GM-CSF and TNF-a are essential for DCs to be generated from these primitive populations. To our surprise most (>80%) generated cells expressed high levels of DC surface markers such as DEC205 and MHC class II, and they were potent stimulators in the primary allogeneic T cell activation. The development of DCs from c-kit(<low) cells was slower than that from c-kit(low) cells. These results indicate that c-kit(<low) cells are more primitive than c-kit(low) cells, although both c-kit*(low) cells and c-kit(<low) cells can differentiate into DCs. It should be noted that the combination of these cytokines selectively induces DCs from both c-kit(<low) and c-kit(low) cells in vitro, suggesting that the ex vivo expansion of DCs using these primitive cells would be applicable to immunotherapy.

Animals↗
PubMed2000

A new method for bone marrow cell harvesting.

To minimize contamination of bone marrow cells (BMCs) with T cells from the peripheral blood, a new "perfusion method" for collecting BMCs is proposed using cynomolgus monkeys. Two BM puncture needles are inserted into a long bone such as the humerus, femur, or tibia. One needle is connected to an extension tube and the end of the tube is inserted into a culture flask to collect the BM fluid. The other needle is connected to a syringe containing 30 ml of phosphate-buffered saline. The solution is pushed gently from the syringe into the medullary cavity, and the medium containing the BM fluid is collected into the culture flask. There is significantly less contamination with peripheral blood, determined from the frequencies of CD4(+) and CD8(+) T cells, when using this method (<6%) than when using the conventional method (>20%) consisting of multiple BM aspirations from the iliac crest. Furthermore, the number and progenitor activities of the cells harvested using this "perfusion method" are greater than those harvested using the conventional aspiration method. This perfusion method was carried out 42 times using 15 cynomolgus monkeys, and no complications such as pulmonary infarction or paralysis were observed. These findings suggest that the "perfusion method" is safe and simple and would be of great advantage in obtaining pure BMCs, resulting in a less frequent occurrence of acute graft-versus-host-disease in allogeneic BM transplantation.

Animals↗
PubMed2000

Effect of alcohol intake on the levels of plasma homocysteine in healthy males.

Hyperhomocysteinemia in chronic alcoholics has been reported, but it remains unclear whether relatively low alcohol intake compared with the previous reports affects the plasma homocysteine level. To investigate this issue, we performed two studies, a population-based study and an alcohol withdrawal study. An analysis of plasma homocysteine levels in a population of 236 healthy males showed no significant association between alcohol consumption and other tested parameters. In the withdrawal study, the subjects with a history of daily alcohol consumption (81.8 +/- 33.0 g/d, mean +/- SD, 40-150g/d, range) abstained from alcohol for 4 wk. After withdrawal, the levels of serum gamma-glutamyl transpeptidase, aspartate aminotransferase, triglycerides, and high-density lipoprotein cholesterol significantly decreased, but the plasma homocysteine level did not change. These results suggest that alcohol intake, at least as far as the amount of beverages our study subjects consumed, has no effect on the plasma homocysteine level in healthy males.

Adult↗
PubMed2000

Effect of segmental transcatheter arterial chemoembolization on branched chain amino acids and tyrosine ratio in patients with hepatocellular carcinoma.

The effect of segmental transcatheter arterial chemoembolization (TAE) on serum amino acid levels and liver function were studied in 23 patients with HCC associated with hepatitis virus C (22 patients) or alcoholism (1 patient), with compensated liver cirrhosis (Child A 18 patients, Child B 5 patients). Serum levels of branched-chain amino acids (BCAA), tyrosine, branched-chain amino acids to tyrosine ratio (BTR), ammonia, total bilirubin and albumin, and prothrombin times were measured before and after TAE (24 h, 7 and 14 days). The BTR was increased significantly 24 h after TAE (p<0.001) and gradually decreased to pre-TAE levels. Serum tyrosine levels decreased at 24 h after TAE (p<0.005) and later increased. Serum BCAA levels increased slightly at 7days after TAE and were decreased at 14 days after TAE. This results indicated that the increased BTR was due primarily to the decreased tyrosine level at 24 h after TAE. Serum ammonia levels gradually decreased after TAE and the prothrombin time and serum levels of total bilirubin and albumin were not significantly changed. In this study, segmental TAE had little influence on liver function, and the BTR unexpectedly increased at 24 h after TAE. These results suggest that segmental TAE has minimal side effects and may have a beneficial effect on amino acid metabolism.

Adult↗
PubMed2000

Mixed-Valent Heptairon Complex with a Ground-State Spin Value of S=12/2 Constructed from a Triiron Cluster Ligand.

The anionic triiron(III) cluster ligand [Fe(III)(3)(µ(3)-O)(bpca)(2)Cl(4)(EtO)(2)](-) (1; Hbpca=bis(2-pyridylcarbonyl)amine) was prepared as a building block for constructing larger metal assemblies. This "metal cluster complex ligand" was used in the synthesis of the mixed-valent heptairon complex [Fe(II)(1)(2)(EtOH)(2)], which has a ground-state spin value of S=12/2.

Journal Article↗
PubMed2000

Affective picture processing: the late positive potential is modulated by motivational relevance.

Recent studies have shown that the late positive component of the event-related-potential (ERP) is enhanced for emotional pictures, presented in an oddball paradigm, evaluated as distant from an established affective context. In other research, with context-free, random presentation, affectively intense pictures (pleasant and unpleasant) prompted similar enhanced ERP late positivity (compared with the neutral picture response). In an effort to reconcile interpretations of the late positive potential (LPP), ERPs to randomly ordered pictures were assessed, but using the faster presentation rate, brief exposure (1.5 s), and distinct sequences of six pictures, as in studies using an oddball based on evaluative distance. Again, results showed larger LPPs to pleasant and unpleasant pictures, compared with neutral pictures. Furthermore, affective pictures of high arousal elicited larger LPPs than less affectively intense pictures. The data support the view that late positivity to affective pictures is modulated both by their intrinsic motivational significance and the evaluative context of picture presentation.

Adult↗
PubMed2000

Rapid screening of high-risk patients for disorders of purine and pyrimidine metabolism using HPLC-electrospray tandem mass spectrometry of liquid urine or urine-soaked filter paper strips.

BACKGROUND: A rapid and specific screening method for patients at risk of inherited disorders of purine and pyrimidine metabolism is desirable because symptoms are varied and nonspecific. The aim of this study was to develop a rapid and specific method for screening with use of liquid urine samples or urine-soaked filter paper strips. METHODS: Reverse-phase HPLC was combined with electrospray ionization (ESI), tandem mass spectrometry (MS/MS), and detection performed by multiple reaction monitoring. Transitions and instrument settings were established for 17 purines or pyrimidines. Stable-isotope-labeled reference compounds were used as internal standards when available. RESULTS: Total analysis time of this method was 15 min, approximately one-third that of conventional HPLC with ultraviolet detection. Recoveries were 96-107% in urine with added analyte, with two exceptions (hypoxanthine, 64%; xanthine, 79%), and 89-110% in urine-soaked filter paper strips, with three exceptions (hypoxanthine, 65%; xanthine, 77%; 5-hydroxymethyluracil, 80%). The expected abnormalities were easily found in samples from patients with purine nucleoside phosphorylase deficiency, ornithine transcarbamylase deficiency, molybdenum cofactor deficiency, adenylosuccinase deficiency, or dihydropyrimidine dehydrogenase deficiency. CONCLUSIONS: HPLC-ESI MS/MS of urine allows rapid screening for disorders of purine and pyrimidine metabolism. The filter paper strips offer the advantage of easy collection, transport, and storage of the urine samples.

Chromatography, High Pressure Liquid↗
PubMed2000

[A case report of Binswanger type encephalopathy manifested after coronary artery bypass grafting].

A 68-year-old man showed signs of dementia after undergoing triple CABG with cardiopulmonary bypass. Brain CT revealed widespread atrophy and lucency in white matter without any sign of stroke. No critical stenosis in cervical vessels was found in duplex scanning. He kept politeness well, but had severe memory impairment. These findings were characteristic of Binswanger type encephalopathy which must have been latent preoperatively. This disease is caused by ischemic damage in brain stem and white matter due mainly to atherosclerotic micro cerebrovasculopathy, and highly related to hypertension. We have to be aware of intracranial cerebrovascular disease when assessing the risk of brain damage in candidates for CABG.

Aged↗
PubMed2000

Two cases of hypothyroidism complicated by renal dysfunction.

We report two patients in whom hypothyroidism was considered to cause renal dysfunction. Case 1 was a 65-year-old woman who stopped taking levothyroxine sodium for hypothyroidism. After 6 months, she developed proteinuria, edema, weight gain, and renal dysfunction. Renal biopsy revealed focal segmental proliferative glomerulonephritis. After re-administration of levothyroxine sodium, thyroid function and renal function both recovered. Case 2 was a 51-year-old man who presented with edema, difficulty in swallowing, muscular weakness, and fatigue. We diagnosed hypothyroidism, and focal segmental proliferative glomerulonephritis was revealed by renal biopsy. After administration of levothyroxine sodium, his symptoms resolved and his thyroid function and renal function both improved. Our experience suggests that hypothyroidism should be taken into consideration as one of the causes of renal dysfunction.

Aged↗