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Biomedical subjects

K Ishii

Publications and source records attributed to K Ishii.

At least 55 records · Page 3Linked to original sources
PubMed2003

Detection of ion channel activity in Xenopus laevis oocytes expressing Influenza C virus CM2 protein.

To demonstrate the ion channel activity of Influenza C virus CM2, we expressed this protein in oocytes of Xenopus laevis and measured whole cell currents by a two-electrode voltage-clamp method. It was found that the inward currents were induced upon hyperpolarizing the oocyte membranes. The amplitude of the currents increased slowly with time during the hyperpolarizing pulse, and the current-voltage relationship was nonlinear, having a slope that increased with the level of hyperpolarization. These results suggest strongly that CM2 forms a voltage-activated ion channel. The current amplitude was increased to a small extent by lowering the external pH. We also found that the anti-influenza A virus drug amantadine hydrochloride failed to attenuate the inward currents of CM2-expressing oocytes induced by hyperpolarization. The reversal voltage of tail currents was affected by the reduction of [Cl-], but neither by the change of [Na+] nor by that of [K+]. Furthermore, the amplitude of the inward currents was decreased by an anion channel blocker. The data presented here suggest that CM2 protein forms a voltage-activated ion channel permeable to chloride ion.

Animals↗
PubMed2003

Washout measurement of radioisotope implanted by radioactive beams in the rabbit.

Washout of 10C and 11C implanted by radioactive beams in brain and thigh muscle of rabbits was studied. The biological washout effect in a living body is important in the range verification system or three-dimensional volume imaging in heavy ion therapy. Positron emitter beams were implanted in the rabbit and the annihilation gamma-rays were measured by an in situ positron camera which consisted of a pair of scintillation cameras set on either side of the target. The ROI (region of interest) was set as a two-dimensional position distribution and the time-activity curve of the ROI was measured. Experiments were done under two conditions: live and dead. By comparing the two sets of measurement data, it was deduced that there are at least three components in the washout process. Time-activity curves of both brain and thigh muscle were clearly explained by the three-component model analysis. The three components ratios (and washout half-lives) were 35% (2.0 s), 30% (140 s) and 35% (10 191 s) for brain and 30% (10 s), 19% (195 s) and 52% (3175 s) for thigh muscle. The washout effect must be taken into account for the verification of treatment plans by means of positron camera measurements.

Animals↗
PubMed2003

First results from KamLAND: evidence for reactor antineutrino disappearance.

KamLAND has measured the flux of nu;(e)'s from distant nuclear reactors. We find fewer nu;(e) events than expected from standard assumptions about nu;(e) propagation at the 99.95% C.L. In a 162 ton.yr exposure the ratio of the observed inverse beta-decay events to the expected number without nu;(e) disappearance is 0.611+/-0.085(stat)+/-0.041(syst) for nu;(e) energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded.

Journal Article↗
PubMed2003

Meningio-angiomatosis in a patient with focal epilepsy: value of PET in diagnoses and preoperative planning of surgery.

A 17-year-old boy with epileptic seizures due to meningio-angiomatosis without neurofibromatosis type 2 is presented. Low grade astrocytoma in the left temporal lobe was resected when he was 11 years old. A recurrence was suspected on following-up MRI and a positive PET scan with 11C-methionine PET 6 years later around the resected area. The language area was mapped using H2(15)O PET activation technique. The lesion was completely resected while preserving the verbal area assisted by three-dimensional imaging protocol of MR-registered PET. The patient was well and seizure-free for 8 years thereafter without antiepileptic drugs. Histologically, there was an increase of dilated arterioles and meningothelial cell-like spindle cells around them, which are characteristic pathological features of meningio-angiomatosis. It is most likely that angiomatous tissue developed perivascular meningiomatous components and formed the meningio-angiomatosis in our presented case. In addition, we presented our protocol of functional neuro-imaging which was useful in terms of the functional neurosurgery.

Adolescent↗
PubMed2003

Chemical peeling with salicylic acid in polyethylene glycol vehicle suppresses skin tumour development in hairless mice.

BACKGROUND: Chemical peeling with salicylic acid in polyethylene glycol (PEG) vehicle is used clinically to improve the cosmetic appearance of skin that has been damaged by exposure to the sun. It is well known that cancers of the skin such as basal cell carcinoma and squamous cell carcinoma may be induced by the sun. However, the carcinogenic potential of chemical peeling agents has not been studied. OBJECTIVES: To evaluate the effects of chemical peeling with 30% salicylic acid in PEG on skin tumour formation in treated vs. control mice. METHODS: To serve as a model of sun-damaged skin, hairless SKH/hr1 mice were irradiated with ultraviolet (UV) B for 14 weeks, with or without treatment every 2 weeks with 30% salicylic acid in PEG for a total of 18 weeks. RESULTS: Not only was the total number of tumours greatly reduced in the treated vs. the control mice, but skin tumour development was also slower in the treated vs. the control mice. At the final treatment, the fractions of T and B lymphocytes and natural killer cells from spleens of both groups of mice were comparable, and interferon-gamma production did not differ. CONCLUSIONS: Our findings suggest that chemical peeling with salicylic acid in PEG may help to prevent as well as to reduce the number of UVB-induced skin tumours.

Animals↗
PubMed2003

Comparison of microbial communities in four different composting processes as evaluated by denaturing gradient gel electrophoresis analysis.

AIMS: We aimed to systematically understand the composting processes by a comparison of microbial communities during four full-scale composting processes. METHODS AND RESULTS: Microbial communities during the four different full-scale composting processes were analysed by denaturing gradient gel electrophoresis combined with measurement of physicochemical parameters. Two composting processes utilized sewage sludge and two utilized food-waste. Comparison of the four processes indicated that the concentration of dissolved organic carbon was higher in the food-waste-composting than in the sewage-sludge-composting processes, and microbial communities varied with composting substrate. The tendency for different microbes to appear in the composting process with different concentrations of dissolved organic carbon agreed with a previous study that showed that microbial succession occurred with a decrease in dissolved organic carbon in a laboratory-scale food-waste-composting process. CONCLUSIONS: Our results suggested that the main factor affecting microbial communities in the composting process is the concentration of dissolved organic materials. SIGNIFICANCE AND IMPACT OF THE STUDY: In addition to studying microbial communities involved in composting, this research is also the first to study composting mechanisms using molecular methods. The results of our studies may be helpful in the design and management of composting processes.

Bacterial Physiological Phenomena↗
PubMed2003

Striatal infarcts mimicking frontotemporal dementia: a case report.

We described a patient with bilateral striatal infarcts, in whom stereotyped and disinhibited behaviors were insidiously emerged over 2 years mimicking frontotemporal dementia (FTD). A positron emission tomography with 18-fluorodeoxy glucose showed a hypometabolism in the frontal lobes, basal ganglia, and thalami. The peculiar behavioral alterations remained unchanged for the following 7 years, suggesting that the disease is not degenerative but of vascular origin. A disruption of the fronto-subcortical circuits at the level of the striatum or the anterior thalamic peduncle is attributable to the FTD-like behavioral and cognitive syndrome.

Aged↗
PubMed2003

An analysis of cervical lymph nodes metastasis in oral squamous cell carcinoma. Relationship between grade of histopathological malignancy and lymph nodes metastasis.

Cervical lymph nodes metastasis is well known to be an indicator of poor prognosis in patients with oral cancer. This study was considered 38 patients of oral squamous cell carcinoma who were treated at our department from 1993 to 1997. Histological malignancy of initial biopsy in the pretreatment period was evaluated by Anneroth's classification. The relationship of degree of histological malignancy with cervical lymph nodes metastasis were analysed in this study. Metastasis in the cervical lymph nodes was histologically confirmed in 17 out of 38 cases (44.7%). The metastasis located predominantly in the submandibular nodes and superior internal jugular nodes. According to T classification, the rate of metastasis in the cervical lymph nodes in T1 and T2 cases was around 30%, while the rate in T3 and T4 cases tended to be as high as around 60%. However, there was no significant difference. A significant relation was evident between the degree of histological malignancy and metastasis in the cervical lymph nodes (P< 0.01), indicating that the histological malignancy could be served as a predictor for metastasis in the cervical lymph nodes. Among the six parameters, a significant difference was observed only in the degree of keratinization and the mode of invasion (P< 0.05). When the sum of the degree of histological malignancy exceeds 15, metastasis in the cervical lymph nodes should be considered.

Carcinoma, Squamous Cell↗
PubMed2002

Prednisolone (30-60 mg/day) for diseases other than AD decreases amyloid beta-peptides in CSF.

The effect of corticosteroid on the concentration of amyloid beta-peptide (Abeta) in human CSF obtained from 16 patients without dementia treated with prednisolone (> or =30 mg daily) was studied. The concentrations of Abetax-40 and Abetax-42 in CSF decreased after treatment was started (p < 0.002). A moderate- or high-dose regimen of prednisolone decreases Abeta production or increases Abeta degradation in the human brain and deserves further study in AD.

Administration, Oral↗
PubMed2002

The effect of APOE epsilon4 allele on cerebral glucose metabolism in AD is a function of age at onset.

BACKGROUND: Although the APOE epsilon4 allele is a well-known risk factor for developing AD, the impact of the epsilon4 allele on clinical manifestations in patients with AD is still controversial. One possible reason for this controversy is that previous studies did not consider the effect of patient age at symptom onset. OBJECTIVE: To investigate the possible impact of patient age at onset of AD on the effect of APOE genotype on regional cerebral glucose metabolism (rCMRglc). METHODS: The authors compared rCMRglc between probable AD patients (based on criteria of the National Institute of Neurologic Disease and Stroke/AD and Related Disorders Association) with APOE epsilon4/4 and APOE epsilon3/3 alleles in early-onset (< or =65 years old) and late-onset (>65 years old) groups. In each group, the patients with APOE epsilon4/4 and APOE epsilon3/3 alleles were comparable for age at onset, age at examination, sex, disease duration, education level, and severity of dementia. RESULTS: In the early-onset group, the patients with the APOE epsilon4/4 genotype showed a significant decrease of rCMRglc in the medial temporal lobe and a significant increase of rCMRglc in the inferior parietal and posterior temporal cortices as compared with those patients with the APOE epsilon3/3 genotype. In the late-onset group, there were no significant differences in the rCMRglc pattern between the patients with APOE epsilon4/4 and APOE epsilon3/3 alleles. CONCLUSIONS: The current findings indicate that the impact of the APOE epsilon4 genotype on cerebral glucose metabolism of patients with AD may be a function of age at symptom onset.

Age of Onset↗
PubMed2002

Direct probe of the shape resonance mechanism in 2sigma(g)-shell photoionization of the N2 molecule.

Angular distributions of photoelectrons from a 2sigma(g) shell of fixed-in-space N2 molecules have been measured for left- and right-elliptically polarized and for linearly polarized light at several photon energies in the region of sigma(*) shape resonance. That allowed the determination of a set of dipole matrix elements and phase shift differences characterizing the process. These data clearly show the enhancement of the fsigma(u) partial cross section in the resonance simultaneously with an abrupt increase of the corresponding phase shift by pi, which is the first experimental demonstration of the nature of the sigma(*) shape resonance in homonuclear diatomic molecules.

Journal Article↗
PubMed2002

Effect of the antiulcer polysaccharide fraction from Bupleurum falcatum L. on the healing of gastric ulcer induced by acetic acid in rats.

An antiulcer polysaccharide fraction (BR-2) from Bupleurum falcatum L. was examined for its effect on the healing of chronic ulcers induced by acetic acid in rats. When BR-2 was administered orally to the rats, it was shown to be effective in the healing of acetic acid-induced chronic ulcer. This result suggests that the use of herbal prescriptions containing B. falcatum L. may prove useful for the treatment of peptic ulcers.

Acetic Acid↗
PubMed2002

Transient global amnesia: increased signal intensity in the right hippocampus on diffusion-weighted magnetic resonance imaging.

We report on a patient with pure transient global amnesia (TGA) whose magnetic resonance imaging (MRI) demonstrated a small region of increased signal intensity in the right hippocampus on diffusion-weighted imaging (DWI). DWI was sensitive and useful for evaluating the early stage of TGA and might help to explain the pathophysiology of TGA.

Amnesia, Transient Global↗
PubMed2002

Intracellular cytokine analysis of CD4-positive T cells predictive of sustained response to interferon therapy for patients with chronic hepatitis C.

We investigated whether the measurement of serum interleukin 18 (IL-18) and intracellular cytokine analysis of peripheral blood CD4-positive T cells (ICA-CD4+ Tc) of chronic hepatitis C (CH-C) patients before and two weeks after interferon (IFN) administration are useful for predicting sustained response to IFN. Twenty-nine CH-C patients received IFN every day for two weeks and three times a week for 22 weeks. Patients were divided into two groups: responders, in whom serum HCV-RNA was undetectable at the end of the follow-up (week 48), and nonresponders, in whom any other patterns were seen. Before and two weeks after IFN administration, serum IL-18 and ICA-CD4+ Tc as described by Jung et al were measured. Serum IL-18 and the relative prevalence of IFN-gamma+ and IL-4+, IFN-gamma+ and IL-4 (Th-1), and IFN-gamma- and IL-4+ cells in the responders were significantly increased, but only the relative prevalence of Th-1 cells in the nonresponders was increased two weeks after IFN therapy. In conclusion, ICA-CD4+ Tc and the measurement of serum IL-18 might be useful for predicting IFN therapy by comparing the results between before and two weeks after IFN.

CD4-Positive T-Lymphocytes↗
PubMed2002

[Early and long-term outcome for surgical treatment of aortic arch aneurysm].

This study was undertaken to determine the factors that influence the final outcome after the operation of aortic arch aneurysm. Sixty-six patients, the median age was 72 years (range 44 to 90), were operated at our hospital during the 16-year period between 1985 and 2001. Preoperative complications included cardiac in 6 and vascular in 21, ruptured in 13, myocardial ischemia in 21 and stroke in 14. The distal hemiarch (11) and total arch replacement with or without ascending aorta and descending aorta (46) and proximal hemiarch with or without valve operations (7) and other procedures were performed mainly using cardio-pulmonary bypass with moderate deep hypothermia and selective cerebral perfusion. The in-hospital mortality were 6 (9%) and 14 (23%) late deaths occurred. One out of 14 was aneurysm related death. The survival rates were 81% at 1 year and 59% at 5 years. The multivariably determined risk factors for early death and postoperative neurological dysfunction were as follows (p < 0.05) cardiac anoxic arrest time, intubation time and gender.

Adult↗