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Biomedical subjects

T Takeda

Publications and source records attributed to T Takeda.

At least 253 records · Page 14Linked to original sources
PubMed1999

Isolation of tick-borne encephalitis virus from wild rodents and a seroepizootiologic survey in Hokkaido, Japan.

To determine the vertebrate host of tick-borne encephalitis (TBE) virus in the southern part of Hokkaido, Japan, virus isolation was performed using spleens from small mammals captured in the area. Two virus strains were isolated, one strain from Apodemus speciosus and another from Clethrionomys rufocanus. Virus isolates were inoculated onto baby hamster kidney cell monolayers and antigen slides were prepared for an indirect immunofluorescent antibody assay. Two isolates were identified as TBE viruses by monoclonal antibody reactions. To specify the TBE-endemic area in Hokkaido, rodent, horse, and dog sera collected from 1992 to 1997 were tested for neutralization antibody against TBE virus previously isolated from a dog. The positive cases were distributed in four districts in the southern part of Hokkaido.

Animals↗
PubMed1999

Pharmacokinetics of etoposide after intrathoracic instillation to lung cancer patients with pleural effusion.

OBJECTIVE: To examine etoposide (VP16) levels in serum and pleural effusion after intravenous infusion or intrathoracic instillation to lung cancer patients. METHODS: Four patients were administered VP16 by intrathoracic instillation and three patients were administered it intravenously. Serum, urine, and pleural effusion were collected and VP16 levels in the biological fluids were determined by HPLC. Pharmacokinetic parameters were calculated. RESULTS: VP16 distributed rapidly into pleural effusion after intravenous infusion. In two of three patients, VP16 levels in pleural effusion were maintained at constant levels more than 24 hours in spite of the decline in serum VP16 levels. After intrathoracic instillation, VP16 in pleural effusion reached high levels and eliminated slowly. Serum levels of VP16 were relatively low compared with those in pleural effusion. CONCLUSION: It was demonstrated that intrathoracic instillation of VP16 might be useful for managing malignant pleural effusion and reducing systemic side-effects by cutting down the dose.

Adenocarcinoma↗
PubMed1999

Reliable method of monitoring antidromic facial nerve response stimulated via Stensen's duct.

OBJECTIVE: This study aimed to obtain a clear antidromic facial nerve response (ADFNR) with a high detection rate in human subjects. The authors also describe the clinical utility of this technique. BACKGROUND: The ADFNR is a potential that can be used to monitor intratemporal facial nerve function at the early stage of facial palsy. However, it was difficult to obtain an analyzable response with conventional methods. METHODS: The sensitivity of data recorded by percutaneous stimulation conventionally used was compared with those recorded after stimulation through Stensen's duct, and the type of recording electrode was evaluated. In individual normal subjects, the test-retest and right-left differences were compared. RESULTS: The ADFNR elicited by stimulation through Stensen's duct and recorded with a monopolar needle electrode was a useful method to monitor facial nerve impulses. With the use of these methods, the ADFNR detection rate was more than 90%. The test-retest difference was minimal and smaller than the right-left side difference. CONCLUSIONS: The authors recommend that the ADFNR should be used to evaluate changes of unilateral facial nerve function by repeated testing and that the technique described here is useful for monitoring the early changes of facial nerve function in patients with facial palsy.

Adult↗
PubMed1999

[Clinical evaluation of granisetron (BRL43694) in nausea and vomiting induced by anticancer drugs--pediatrics].

Granisetron has been used widely for the prevention and treatment of nausea and vomiting associated with anticancer drugs in adult patients with cancer. This multi-center open study was conducted to study the efficacy, safety and usefulness of granisetron in children with cancer. Among 166 evaluable patients, the efficacy rate (percentage of "remarkably effective" or "effective") was 84.9% and the usefulness rate (percentage of "extremely useful" or "useful") was 87.3%. No serious adverse effects were observed. As granisetron 40 micrograms/kg had an excellent antiemetic effect and a high degree of safety against nausea and vomiting associated with anticancer drugs, it was shown to be useful for children with cancer.

Adolescent↗
PubMed1999

Clonal analysis of non-toxigenic Vibrio cholerae O1 associated with an outbreak of cholera.

We examined the clonal relationships among eight clinical isolates of non-toxigenic (NT) V. cholerae O1 associated with a cluster of cases of cholera in Warangal, Andhra Pradesh in south India and compared their relatedness to toxigenic O1 strains of classical and E1Tor biotypes and with O139 Bengal strains of V. cholerae by pulsed-field gel electrophoresis (PFGE). Phylogentic analysis of the NotI restriction fragment length polymorphism showed that all the NT. V. cholerae O1 strains formed a tight cluster with more than 80 per cent similarity. Interestingly, the NT V. cholerae O1 cluster was more closely related to V. cholerae O139 than to classical and E1Tor biotypes of V. cholerae O1 indicating closer genetic relationships between NT V. cholerae 01 and O139 Bengal strains that were isolated during the same time-frame.

Bacterial Typing Techniques↗
PubMed1999

[Contrast medium injection on CT during hepatic arteriography: comparison of two protocols].

To assess the optimum method of contrast medium injection on CT during hepatic arteriography (CTHA), we performed this procedure in 37 patients using two consecutive protocols (A and B) employing different concentrations of iodine (iohexol at 140 mgI/ml and 300-350 mgI/ml), flow rates (2 ml/sec and 1 ml/sec), and contrast medium volumes (60 ml and 30 ml). Mean parenchymal enhancement of the right lobe and left lateral segment were measured and compared. Enhancement varied significantly more with protocol B, especially in the left lateral segment. These results suggest that a low iodine concentration and high injection rate are suitable for CTHA, to avoid nonuniform parenchymal enhancement.

Adult↗
PubMed1999

Improved recording techniques of antidromic facial nerve response for outpatient clinical use.

OBJECTIVE: The purpose of this study was to obtain an analyzable wave of the antidromic facial nerve response (ADFNR) without interference of the compound muscle action potential (CMAP) at the outpatient clinic setting. BACKGROUND: To evaluate intratemporal facial nerve function with the ADFNR, it is necessary to analyze the waveform of propagating nerve impulses in the temporal bone. However, this small nerve response is easily disturbed by the CMAP, which is simultaneously evoked by electrical stimulation. METHODS: The ADFNR was recorded at the entrance of the external ear canal and simultaneously at the anulus tympanicus. Subtraction between the responses evoked at both sites was performed to eliminate the CMAP. RESULTS: The ADFNR was recorded after subtraction of the response recorded at the entrance of the external ear canal from that at the anulus tympanicus. The normal ADFNR had a triphasic waveform. With the placement of the reference electrode at the entrance of the external ear canal, the responses were similar to the subtracted responses. CONCLUSIONS: We recommend the subtraction method and placement of the reference electrode at the entrance of the external auditory canal to record an analyzable ADFNR and to simplify the recording techniques.

Action Potentials↗
PubMed1999

[A case of significant natriuresis and improvement of proteinuria by Temocapril, an ACE inhibitor with biliary excretion, in loop diuretics resistant edema in membranous nephropathy].

A 50-year-old man with WPW syndrome and chronic atrial fibrillation controlled by digoxin exhibited nephrotic syndrome due to membranous nephropathy in 1994. For massive edema resistant to loop diuretics, administration of 2 mg/day of Temocapril, an ACE inhibitor with biliary excretion, was started. It provided marked natriuresis and rapid improvement of massive anasarca. Moreover, 6 months later at the time of writing this report, nephrotic proteinuria has decreased and abnormally depressed Ccr level has elevated. For massive edema resistant to loop diuretics in nephrotic syndrome, Temocapril might bring about a beneficial effect possibly through the induction of natriuresis, which has been suppressed by the over-expression of angiotensin II in tubulointerstitium.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Expression of rat DNA (cytosine-5) methyltransferase (DNA MTase) in rodent trophoblast giant cells: molecular cloning and characterization of rat DNA MTase.

Methylation of genomic DNA is involved in the basic methanism of gene inactivation, chromatin organization, X chromosome inactivation and genomic imprinting. A pattern of DNA methylation is maintained in mitotic cells by DNA (cytosine-5) methytransferase (DNA MTase). The DNA MTase has been shown to be also expressed in postmitotic cells such as neurons. In the present report, as an approch to analyzing mechanisms underlying regulation of DNA MTase expression, we first isolated rat DNA MTase cDNA. The isolated cDNA encoded a protein of 1,622 amino acid residues showing 88.3% and 64.2% of homology with mouse and human DNA MTase, respectively. Northern blot analysis showed that DNA MTase mRNA was highly expressed in placenta during mid- to late- pregnancy. We then analyzed the expression of DNA MTase in Rcho-1 cells, a rat choriocarcinoma-derived cell line, which cease cell division but keep replicating genomic DNA when differentiated in vitro. We found that the expression of DNA MTase protein was decreased in terminally differentiated Rcho-1 cells whereas DNA MTase mRNA was consistently expressed. This result suggested posttranscriptional regulation of DNA MTase activity in Rcho-1 cells. The Rcho-1 cells would be a valuable model for studying the regulation of gene expression and function of DNA MTase in postmitotic, differentiated cells.

Amino Acid Sequence↗
PubMed1998

Temporal process from receptors to higher brain in taste detection studied by gustatory-evoked magnetic fields and reaction times.

Using magnetoencephalography (MEG) and a taste stimulator with rapid-rise time, we previously located the primary gustatory area in the human cerebral cortex and also investigated the relation between the onset latency of the gustatory-evoked magnetic fields (GEM) and reaction times (RT) in different taste qualities. In the present study, we investigated the temporal process from receptors to the higher brain in taste detection based on the results of the GEM and RT of different tastes. We used 100 mM, 300 mM and 1 M NaCl and 3 mM saccharine. The duration of each stimulus was 400 ms. The interstimulus interval was approximately 30 s. The temperature of both taste solution and deionized water was maintained the same as that of the tongue. Four subjects participated in this experiment. The 64-channel whole-head SQUID system (CTF Systems Inc., Canada) was used to measure GEM. The sampling rate was 250 Hz, and the low-pass filter was 40 Hz. In each subject, GEM and RT to a given taste were measured separately by applying 40 trials of stimulation. After each trial of both measurements, subjects showed a perceived intensity by using their fingers. In the GEM study, the trials contaminated with eye movements were rejected and the remaining trials were averaged. Averaged GEM were super-imposed on the same sheet with all 64 channels to measure the onset latency of GEM from the stimulus onset. RT and onset latencies of GEM were longer for saccharine than NaCl, and the value of RT minus the onset latency of GEM from RT, presumably indicating the time for higher brain process plus motor process, did not differ between 3 mM saccharine and 1 M NaCl. With increased concentrations of NaCl, RT became shorter, but onset latencies of GEM remained constant. Sweet taste took a longer time than salty taste at receptor process including the time for diffusion to receptors.

Cerebral Cortex↗
PubMed1998

Frequent aberration of FHIT gene expression in acute leukemias.

We analyzed the mRNA expression of the FHIT gene by reverse transcription-PCR (RT-PCR) in 54 cases of acute lymphoblastic leukemia (ALL; 11 cases of T-cell ALL [T-ALL] and 43 cases of non-T-ALL) and 40 cases of acute myeloid leukemia (AML). In 46% of the ALL cases and 55% of the AML cases, FHIT expression was absent or markedly decreased. Only abnormal short bands were detected in 30% of the ALL cases and 5% of the AML cases. Eighteen of 19 abnormal transcripts had the same fusion of exons 2-7, and all lacked the starting codon in exon 5. No obvious normal-sized PCR products were detected in cases exhibiting abnormal transcripts. These findings suggest that the expression of functional FHIT protein was lost in the majority of ALL (76%) and AML (60%) cases. Differential quantitative PCR of exons 3-9 of the FHIT gene and RT-PCR of the PTPRG gene, which is centromeric to the FHIT gene, showed the presence of the target sequences. Fluorescence in situ hybridization analysis using probes covering exons 5 and 8 revealed no difference in the signal patterns between leukemia and normal cells, showing one or two signal doublets in more than 90% of nuclei, and indicated that gross segments of the FHIT gene were not homozygously deleted in these cases. A small number of transcripts with an aberrant fusion between exons 2 and 7 were detected by RT-PCR in the bone marrow cells from four healthy individuals. Granulocytes, lymphocytes, and monocytes in the bone marrow cells of a healthy individual contained transcripts with the same fusion. This unique fusion of exons 2 and 7 might be preferentially seen in either neoplastic or normal hematopoietic cells, regardless of their lineage. The finding that FHIT expression was abolished in the majority of leukemia cases might support the hypothesis that the FHIT gene acts as a tumor suppressor, at least in leukemia.

Acid Anhydride Hydrolases↗
PubMed1998

Human microvascular endothelial cells are strongly sensitive to Shiga toxins.

We show here that the susceptibility of endothelial cells to Shiga toxin (Stx)s differs remarkably depending on their cellular origins. The concentration of Stx-1 required to reduce cell viability by 50% as measured by MTT assay was 30 and 300 fM for neonatal and adult human microvascular endothelial cells (HMVEC), respectively, and 30 pM for human coronary artery endothelial cells (HCAEC). Human umbilical venous endothelial cells (HUVEC) and bovine aortic endothelial cells (BAEC) showed no sensitivities to Stx-1. Surprisingly, Stx-2 was approximately 10-100 times more toxic to HMVEC than Stx-1. Moreover sodium butyrate sensitized HMVEC by 100-fold to the cytotoxic activity of Stxs. These results were found to reflect the amount of Gb3/CD77 on the cell surface on a per cell basis using flow cytometrical analysis. The high sensitivity of HMVEC to Stxs suggests their involvement in the pathogenesis of organ failure induced by Stx-producing Escherichia coli.

Adult↗
PubMed1998

Age-related changes in the brains of senescence-accelerated mice (SAM): association with glial and endothelial reactions.

Twelve substrains of inbred senescence-accelerated mice (SAM) have been developed, among which the SAMP8 and SAMP10 strains show a significant age-related deterioration in learning and memory for passive and active avoidance tasks. These strains have, respectively, a low and high incidence of systemic senile amyloidosis. Although we found no amyloid deposits in their brain parenchyma, a variety of age-related alterations were identified, involving neurons, glia, and vessels in the brain tissues. Here we review the degenerative changes in aged SAMP8 and SAMP10 brains. These changes are generally similar to the pathology of aging human brain and may be characterized by their association with some specific glial reactions.

Aging↗
PubMed1998

Inhibition of ascorbate peroxidase under oxidative stress in tobacco having bacterial catalase in chloroplasts.

To analyze the potential of the active oxygen-scavenging system of chloroplasts, we introduced Escherichia coli catalase into tobacco chloroplasts. Photosynthesis of transgenic plants was tolerant to high irradiance under drought conditions, while the wild plants suffered severe damage in photosynthesis under the same conditions. Irrespective of responses to the stress, ascorbate peroxidase was completely inactivated both in the transgenic and wild-type plants. These findings are contrary to the established idea that the ascorbate peroxidase-mediated antioxidative system protects chloroplasts from oxidative stress.

Ascorbate Peroxidases↗
PubMed1998

Mass screening for neuroblastoma targeting children age 14 months in Sapporo City: a preliminary report.

BACKGROUND: In Sapporo City a mass screening program for neuroblastoma targeting children age 6 months (6-MS) was initially introduced in 1981. Since April 1991, an additional program has been implemented, aimed at children age 14 months (14-MS). METHODS: High performance liquid chromatography was employed in the 14-MS. Identification of cases was dependent on the Registry of Childhood Malignancies in the Hokkaido Prefecture. RESULTS: Of the 85,783 live births in Sapporo City during the period 1990-1994, a total of 56,444 participated in the 14-MS (compliance rate, 65.8%). By the end of 1996, of 48,448 children who had previously taken part in the 6-MS, 6 cases were identified in the 14-MS, and 1 additional case screened negative but was later diagnosed clinically. Two more cases were detected in the 14-MS among the 7996 children who had not participated in the 6-MS. Though the incidence of cases identified by the 14-MS was much higher than expected, several true-positive cases had unfavorable histology (as defined by Shimada's classification), a high dopamine level, and/or a high homovanillic acid/vanillylmandelic acid ratio. CONCLUSIONS: Mass screening of children age 14 months for neuroblastoma detects cases missed or unscreened at age 6 months, though the detection rate appears to be in excess of what would be expected from natural incidence.

Cross-Sectional Studies↗
PubMed1998

Comparative study on recombinant chloroplastic and cytosolic ascorbate peroxidase isozymes of spinach.

The spinach stromal, thylakoid-bound, and cytosolic ascorbate peroxidase isozymes (EC 1.11.1.11) were overexpressed in Escherichia coli, and their enzymatic properties were compared with the respective native isozymes. The purification of the recombinant stromal and cytosolic ascorbate peroxidases using the conventional column chromatography yielded 0.73 and 2.2 mg of protein/liter of bacteria culture with enzyme activities of 800 and 486 micromol min-1 mg protein-1, respectively. In every respect, the recombinant stromal, thylakoid-bound, and cytosolic ascorbate peroxidase isozymes exhibited identical enzymatic properties with each native isozyme. Specifically, the recombinant stromal and thylakoid-bound ascorbate peroxidase isozymes showed high utilization of ascorbate as an electron donor and had a very short lifetime in ascorbate-depleted medium. Polyclonal antibodies raised against both purified recombinant stromal and cytosolic ascorbate peroxidase isozymes were prepared. Both antibodies showed a cross-reaction with the recombinant and native ascorbate peroxidase isozymes.

Amino Acid Sequence↗
PubMed1998

Phase-Contrast Tomographic Imaging Using an X-ray Interferometer.

Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays.

Journal Article↗