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Biomedical subjects

T Saito

Publications and source records attributed to T Saito.

At least 55 records · Page 3Linked to original sources
PubMed2005

Ileocolonic lymphomas: a series of 16 cases.

BACKGROUND: Colonoscopic and clinical differences between primary ileocolonic mucosa-associated lymphoid tissue (MALT) lymphoma and mantle cell lymphoma (MCL) have not been defined. METHODS: We reviewed colonoscopic and clinical features in eight patients with primary MALT lymphoma and eight patients with MCL in the terminal ileum and/or colorectum. All cases were examined for CD5 and/or cyclin D1 expression. RESULTS: Endoscopic features of MALT lymphoma were characterized as protrusions that were covered with normal-appearing mucosa with or without ulceration. The gross appearances of MALT lymphomas were categorized as solitary (4 patients), multiple (3 patients), and multiple lymphomatous polyposis (MLP) (1 patient). The gross features of MCL at endoscopy were categorized as multiple protrusions (2 patients), and MLP (6 patients). The clinical stages of patients with MCL were more advanced than in patients with MALT lymphoma. CONCLUSIONS: Solitary or multiple protrusions at an early clinical stage is the most common presentation pattern of patients with MALT lymphoma, but an MLP appearance at an early stage is also possible. On the other hand, MLP appearance with an advanced clinical stage is the main presentation pattern in patients with MCL, although multiple protrusions with an early clinical stage is also possible. Histological and immunohistochemical investigation including that of cyclin D1 and CD5 expression is essential to make the final diagnosis.

Adult↗
PubMed2005

Ethnic differences between Japanese and Caucasians in the expression levels of mRNAs for CYP3A4, CYP3A5 and CYP3A7: lack of co-regulation of the expression of CYP3A in Japanese livers.

Using a newly developed real-time reverse transcriptase-polymerase chain reaction method, mRNAs were quantitated for CYP3A4, CYP3A5 and CYP3A7 in adult livers from 24 Japanese and 24 Caucasian subjects to elucidate the potential ethnic differences in the expression levels of human cytochrome P450 (CYP) 3As. The expression level of CYP3A4 mRNA in Japanese livers (n = 24) was approximately three times higher than that in Caucasian livers (n = 24, p < 0.001). The mean level of CYP3A5 mRNA was approximately twice higher in Japanese (n = 9) than in Caucasians (n = 5) heterozygous for the CYP3A5 *1 allele (p = 0.057). The CYP3A7 mRNA level was twice higher in Japanese (n = 24) than in Caucasians (n = 22) carrying the CYP3A7 *1A/ *1A genotype (p = 0.042). The level of CYP3A4 mRNA did not correlate with those of CYP3A5 (r = 0.044, n = 24) or CYP3A7 (r = 0.21, n = 24) mRNAs in Japanese livers in contrast to co-regulatory expression of CYP3A4, CYP3A5 and CYP3A7 in Caucasian livers. The results indicate that there are ethnic differences in the expression levels of adult liver CYP3A mRNAs between Japanese and Caucasians, and that the mechanism(s) regulating the hepatic CYP3A expression may be different between these ethnic groups.

Aryl Hydrocarbon Hydroxylases↗
PubMed2005

Measurements of the response functions of a large size NE213 organic liquid scintillator for neutrons up to 800 MeV.

The response functions of 25.4 cm (length) x 25.4 cm (diameter) NE213 organic liquid scintillator have been measured for neutrons in the energy range from 20 to 800 MeV at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) and at the Research Center for Nuclear Physics (RCNP) of Osaka University. At HIMAC, white (continuous) energy spectrum neutrons were produced by the 400 MeV per nucleon carbon ion bombardment on a thick graphite target, whose energy spectrum has already been measured by Kurosawa et al., [Nucl. Sci. Eng. 132, 30 (1999)] and the response functions of the time-of-flight-gated monoenergetic neutrons in a wide energy range from 20 to 800 MeV were simultaneously measured. At RCNP, the quasi-monoenergetic neutrons were produced via 7Li(p,n)7Be reaction by 250 MeV proton beam bombardment on a thin 7Li target, and the TOF-gated 245 MeV peak neutrons were measured. The absolute peak neutron yield was obtained by the measurement of 478 keV gamma rays from the 7Be nuclei produced in a Li target. The measured results show that the response functions for monoenergetic neutrons < 250 MeV have a recoil proton plateau and an edge around the maximum light output, which increases with increasing incident neutron energy, on the other hand > 250 MeV, the plateau and the edge become unclear because the proton range becomes longer than the detector size and the escaping protons increase. It can be found that the efficiency of the 24.5 cm (diameter) x 25.4 cm (length) NE213 for the 250 MeV neutrons is -10 times larger than the 12.7 cm (length) x 12.7 cm (diameter) NE213, which is widely used as a neutron spectrometer.

Electrons↗
PubMed2005

Cannabinoids modulate synaptic activity in the rat supraoptic nucleus.

In the present study, we investigated the effects of the cannabinoid receptor agonist CP55,940 on excitatory and inhibitory synaptic transmission in the rat supraoptic nucleus. Whole-cell patch clamp recordings were performed on supraoptic neurones in in vitro brain slice preparations. CP55,940 significantly reduced the frequency of spontaneous excitatory and inhibitory postsynaptic currents in a concentration-dependent manner. These changes were potently reversed by the CB1 receptor antagonist AM251. The results indicate that cannabinoids modulate the activity of magnocellular neurosecretory neurones by presynaptic inhibition of both excitatory and inhibitory synaptic transmission.

Anesthetics, Local↗
PubMed2005

Relationship between obesity, glucose tolerance, and periodontal disease in Japanese women: the Hisayama study.

BACKGROUND: Recent studies have reported a relationship between obesity and periodontal disease. Obesity is the strongest risk factor for type 2 diabetes, which is, in turn, a risk factor for periodontal disease. An oral glucose tolerance test is necessary to diagnose diabetes; however, no study has examined the relationship between obesity and periodontal disease by taking oral glucose tolerance test results into consideration. METHODS: In all, 584 Japanese women aged between 40 and 79 years old, with at least 10 teeth, underwent health examinations. Body mass index, waist-hip ratio, body fat, and oral glucose tolerance test results were used as independent variables with known risk factors for periodontal disease. Mean probing pocket depth and mean attachment loss were used as the dependent variables. RESULTS: In all of the analyses, body mass index, body fat, and waist--hip ratio were significantly associated with the highest quintile of mean probing pocket depth, even when adjusted for oral glucose tolerance test results. In the multivariate analysis, the subjects with the highest quartile of body mass index had a significantly higher odds ratio (OR) for the highest quintile of mean probing pocket depth [OR, 4.3; 95% confidence interval (CI), 2.1--8.9; p<0.001], whereas neither impaired glucose tolerance nor diabetes were significantly associated with deep pockets. The relationships between the obesity indexes and mean attachment loss did not reach statistical significance. CONCLUSION: Obesity was associated with deep pockets in Japanese women, even after adjusting for oral glucose tolerance test.

Adult↗
PubMed2005

Disclosure preferences regarding cancer diagnosis and prognosis: to tell or not to tell?

Telling people that they have cancer has a great impact on their lives, so many doctors are concerned about how they should inform patients about a cancer diagnosis and its prognosis. We conducted a general population survey in Japan to investigate people's preferences on receiving this information. There were no significant differences in respondents' preferences according to the seriousness of the cancer. Full disclosure of the diagnosis was preferred by 86.1% of the respondents, while 2.7% wanted non-disclosure. As for the initial provision of information, the majority preferred partial disclosure concerning the prospects of complete recovery (64.5%) and the expected length of survival (64.1%). Those who responded negatively to the statement, "If I am close to the end of my life, I want to be informed of the fact so I can choose my own way of life", were more likely to want non-disclosure on diagnosis. The results suggest that, at the first opportunity of providing information, a disclosure policy of giving patients full details of their diagnosis and some information on prognosis can satisfy the preferences of most patients. Contrary to popular belief, the seriousness of the cancer and people's demographic characteristics displayed little impact in this study.

Adult↗
PubMed2005

Age associated axonal features in HNPP with 17p11.2 deletion in Japan.

OBJECTIVE: To clarify age related changes in the clinicopathological features of hereditary neuropathy with liability to pressure palsy (HNPP) in Japanese patients with deletion of 17p11.2, particularly concerning axonal abnormalities. METHODS: Forty eight proband patients from 48 HNPP families were assessed as to clinical, electrophysiological, and histopathological features, including age associated changes beyond those in controls. RESULTS: Motor conduction studies showed age associated deterioration of compound muscle action potentials in nerves vulnerable to repetitive compression (median, ulnar, and peroneal nerves), but not in others such as the tibial nerve. Sensory conduction studies revealed more profound reduction of action potentials than motor studies with little age related change. Large myelinated fibre loss was seen in the sural nerve irrespective of age at examination. CONCLUSIONS: Irreversible axonal damage may occur at entrapment sites in motor nerves in HNPP patients, progressing with aging. Sensory nerves may show more profound axonal abnormality, but without age association. The electrophysiological features of HNPP are presumed to be a mixture of abnormalities occurring from early in life and acquired features caused by repetitive insults at entrapment sites. Unlike Charcot-Marie-Tooth disease type 1A, age associated axonal damage may not occur unless the nerves are subjected to compression.

Action Potentials↗
PubMed2005

Impaired ambulatory venous function in lymphedema assessed by near-infrared spectroscopy.

AIM: The aim of this study was to investigate venous function in patients with leg lymphedema during exercise using near-infrared spectroscopy (NIRS), compared with that of patients with chronic venous insufficiency (CVI). METHODS: Forty-three legs of 33 patients (5 males, 28 females; mean age: 53 years) with leg lymphedema without varicose veins or deep vein thrombosis underwent a treadmill walking test with simultaneous NIRS. For comparison, 136 legs of 91 patients (35 males, 56 females; mean age: 56 years) with varicose veins as a CVI group and 45 legs of 38 healthy volunteers (23 males, 15 females; mean age: 50 years) were also evaluated in the same method. Deoxygenated hemoglobin (HHb) was continuously measured during exercise, and the ambulatory venous retention index (AVRI) of each leg was obtained from the serial changes in HHb. RESULTS: The mean AVRI of the lymphedema group was significantly higher than that of healthy legs and significantly lower than of legs with moderate or severe CVI. Furthermore, it was similar to that in the mild CVI group. CONCLUSIONS: Venous function is impaired in exercising legs with lymphedema, and corresponds to that in legs with mild venous insufficiency. The treatment of lymphedema should take CVI into consideration.

Adult↗
PubMed2005

[Cardiac papillary fibroelastomas: report of 2 cases].

We report 2 cases of cardiac papillary fibroelastomas in adults. Case 1: A 61-year-old man was admitted because echocardiography showed a 1 cm pedunculated papillary tumor in the left atrium. In an operation, it was located in the left atrium near the mitral valve and was resected along with a 5 mm margin of endocardium. Case 2: A 60-year-old woman had a 1 cm mobile tumor in the right ventricle near the tricuspid valve located by echocardiography in a preoperative examination of a ventricular septal defect. In an operation, a pedunculated tumor located in the right ventricle was resected. In these 2 cases, histopathology showed the tumor to be a papillary fibroelastoma. Almost all cardiac papillary fibroelastoma are closely related to the cardiac valve, but in these cases, the tumors were located in the left atrium, and the right ventricle, respectively, which is quite rare.

Cardiac Surgical Procedures↗
PubMed2004

Attenuation of brain derived neurotrophic factor (BDNF) by ethanol and cytoprotective effect of exogenous BDNF against ethanol damage in neuronal cells.

Ethanol-induced cell damage was investigated using human neuroblastomas SH-SY5Y cells, which can be differentiated by retinoic acid. With 100 mM or more of ethanol, cytotoxicity was significantly higher in undifferentiated cells than in differentiated cells. Thus, a severer effect of ethanol was observed in undifferentiated cells. In differentiated cells it was shown that the secreted amount of brain derived neurotrophic factor (BDNF) and the cyclic AMP responsive element binding protein (CREB) activity were significantly reduced by ethanol. These effects may be involved in ethanol-induced cell damage in differentiated cells. It was reported that neurotrophic factors have protective effects and that the hippocampus exclusively was damaged by ethanol. Since SH-SY5Y cell is a cell line (a neuronal cell model) and similar cytotoxic effect of ethanol was observed in both SH-SY5Y and primary culture neuronal cells, it will be favorable to use primary culture cells to test a protective effect of BDNF. Exogenous BDNF was shown to have a protective effect against ethanol-induced damage in primary culture neurons from rat hippocampi.

Alcohol-Induced Disorders, Nervous System↗
PubMed2004

Measurement of the generalized forward spin polarizabilities of the neutron.

The generalized forward spin polarizabilities gamma(0) and delta(LT) of the neutron have been extracted for the first time in a Q2 range from 0.1 to 0.9 GeV2. Since gamma(0) is sensitive to nucleon resonances and delta(LT) is insensitive to the Delta resonance, it is expected that the pair of forward spin polarizabilities should provide benchmark tests of the current understanding of the chiral dynamics of QCD. The new results on delta(LT) show significant disagreement with chiral perturbation theory calculations, while the data for gamma(0) at low Q2 are in good agreement with a next-to-leading-order relativistic baryon chiral perturbation theory calculation. The data show good agreement with the phenomenological MAID model.

Journal Article↗
PubMed2004

Kinetic study of racemization of aspartyl residues in synthetic elastin peptides.

We previously reported that biologically uncommon D-aspartyl residues are present in sun-damaged skin from elderly people, possibly in elastin. Here, we report the kinetics of Asp racemization in model peptides corresponding to elastin sequences from exons 6 and 26. We estimated the activation energy (E) of racemization of Asp residues, the racemization rates (RR) at 37 degrees C and the time (t) required for the D/L ratio of Asp to approximate to 1.0 (D/L ratio of Asp=0.99) at 37 degrees C. For an exon 6 peptide, E=29.0 kcal/mol, RR=2.59 x 10(-2)/yr and t=101.0 yr. For an exon 26A peptide E=26.2 kcal/mol, RR=4.27 x 10(-2)/yr and t=61.3 yr; and for a second exon 26A peptide E=25.7 kcal/mol, RR=5.55 x 10(-2)/yr and t=47.0 yr. These results suggest that racemization of Asp residues in elastin could occur within a human life span. We propose that D-Asp could be a useful molecular indicators of aging.

Aging↗
PubMed2004

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun.

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Journal Article↗
PubMed2004

Clinical factors associated with fluconazole resistance and short-term survival in patients with Candida bloodstream infection.

In a 1-year national surveillance program of Candida bloodstream infections in Japan, clinical factors predicting fluconazole resistance and survival of the patients were analyzed. Blood isolates and complete clinical histories were obtained from 326 patients. Fluconazole-resistant isolates were found in 15 (4.6%) of the cases. Univariate analysis of the demographic and clinical factors associated with fluconazole resistance revealed that age, hematologic malignancy, neutropenia, and immunosuppression were of statistical significance. A multiple logistic regression model showed that only hematologic malignancy as the underlying disease (odds ratio, 6.6; 95% confidence interval, 1.6-26.9; P=0.009) was independently associated with resistance. In 242 cases in which data regarding management and prognosis were available, the 30-day survival rate was 68.4%. In the univariate analysis of factors predicting survival, a significant association was found for Candida species, age of the patient, neutropenia, recent abdominal surgery, removal of the central venous catheter, and use of appropriate antifungal therapy. In the multivariate analysis, removal of the central venous catheter (odds ratio, 6.0; 95% confidence interval, 2.2-16.1; P<0.001) and the use of appropriate therapy (odds ratio, 2.1; 95% confidence interval, 1.1-4.1; P=0.03) were independent factors significantly associated with survival after the diagnosis of Candida bloodstream infection.

Adolescent↗
PubMed2004

Neurotoxic potential of haloperidol in comparison with risperidone: implication of Akt-mediated signal changes by haloperidol.

The neurotoxicity of conventional antipsychotic drugs has emerged as a potential pathogenic event in extrapyramidal side effects (EPS) and in their limited efficacy for negative-cognitive symptoms in schizophrenic patients. The atypical antipsychotics, recently developed, have superior therapeutic efficacy to treat not only positive symptoms but negative symptoms and cognitive dysfunctions with much lower potentials of side effects, although the influence of atypical antipsychotics on the regulation of neuronal survival has been less investigated. It is important to clarify the effects of typical and atypical antipsychotics on neuronal survival and their contributions to the therapeutic development and understanding of the pathophysiology of schizophrenia. We measured the neurotoxicity of two antipsychotic drug treatments, haloperidol and risperidone, in primary cultured rat cortical neurons. Immunoblotting and pharmacological agent analyses were used to determine the signal transduction changes implicated in the mechanisms of the neurotoxicity. Haloperidol induced apoptotic injury in cultured cortical neurons, but risperidone showed weak potential to injure the neurons. Treatment with haloperidol also led the reduction of phosphorylation levels of Akt, and activated caspase-3. The D2 agonist bromocriptine and 5-HT2A antagonist, ketanserin attenuated the haloperidol-induced neuronal toxicity. Moreover, brain-derived neurotrophic factor (BDNF) reduced the caspase-3 activity and protected neurons from haloperidol-induced apoptosis. BDNF also reversed the reduced levels of phosphorylation of Akt caused by treatment with haloperidol. Haloperidol but not risperidone induces caspase-dependent apoptosis by reducing cellular survival signaling, which possibly contributes to the differential clinical therapeutic efficacy and expression of side effects in schizophrenia.

Animals↗
PubMed2004

Q2 evolution of the neutron spin structure moments using a 3He target.

We have measured the spin structure functions g(1) and g(2) of 3He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.058 GeV off a polarized 3He target at a 15.5 degrees scattering angle. Excitation energies covered the resonance and the onset of the deep inelastic regions. We have determined for the first time the Q2 evolution of Gamma(1)(Q2)= integral (1)(0)g(1)(x,Q2)dx, Gamma(2)(Q2)= integral (1)(0)g(2)(x,Q2)dx, and d(2)(Q2)= integral (1)(0)x(2)[2g(1)(x,Q2)+3g(2)(x,Q2)]dx for the neutron in the range 0.1< or =Q2< or =0.9 GeV2 with good precision. Gamma(1)(Q2) displays a smooth variation from high to low Q2. The Burkhardt-Cottingham sum rule holds within uncertainties and d(2) is nonzero over the measured range.

Journal Article↗
PubMed2004

The transcriptional program of synchronous gametogenesis in Chlamydomonas reinhardtii.

Cells of Chlamydomonas reinhardtii undergo gametogenesis to produce sexually competent gametes under nitrogen-starved conditions. By using a synchronized system for gametogenesis of early G1 cells, several previously identified marker genes and 18 novel nitrogen-starved gametogenesis (NSG) genes isolated by macroarray analysis were placed into at least three temporal classes of expression. Early genes are induced transiently in the first 2 h after transfer to nitrogen-free medium. Middle genes are strongly induced between 3 h and 4 h after nitrogen removal, a time corresponding to the acquisition of mating competency, suggesting their involvement in the gamete program. Late genes are induced between 5 h and 8 h after nitrogen removal, a time after the completion of gametic differentiation, suggesting that they are not directly involved in the formation of sexually competent gametes. All of the 18 NSG genes examined are induced in both mating-type plus and minus gametes and about two-thirds of the genes are also expressed in the mitotic cell cycle, especially at S/M phases.

Animals↗