Search PubMed⌕ Search

Biomedical subjects

A Tanaka

Publications and source records attributed to A Tanaka.

At least 451 records · Page 25Linked to original sources
PubMed1999

Vagal nerve activity and the high frequency peak of the heart rate variability.

For the Quality of life (QOL) of patients with an artificial heart system, monitoring an information of the cardiovascular control system may be important. We have been evaluating the autonomic nervous system for that purpose. Recently, fluctuations in hemodynamic parameters including heart rate variability (HRV) were evaluated by means of spectral analysis and nonlinear mathematical analysis. Respiratory wavers in HRV were thought to reflect ongoing information of the parasympathetic nerve activity. Is it true? In order to confirm this hypothesis, we recorded vagal nerve activity directly in the chronic animal experiments. Six healthy adult goats were anesthetized with Halothene inhalation and thoracotomy were performed by the fourth lib resection during mechanical ventilation. Arterial blood pressure, right and left atrial pressures were continuously monitored with the catheter insertion. Cardiac output was measured by the electromagnetic flowmeter attached to the ascending aorta. After the chest was closed, incision was made to the left neck and left vagal nerve was separated. Stainless steel electrodes were inserted into the vagal nerve and fixed by the plasticizer. After the incision was closed, the goats were transferred to the cage and extubated after waking. Hemodynamic parameters and vagal nerve activity were measured in the awake condition. The results showed that clear observation of the autonomic nerve discharges were embodied by this experimental system. The vagal nerve discharges were synchronized with heart beat and respiration. The vagal nerve tonus was significantly influenced by the hemodynamic alteration. However in some condition, the respiratory wave was not always consistent with tonus of the vagal nerve activity, thus suggesting that we should check another information to evaluate the parasympathetic tone. We must continue this study to evaluate an autonomic nerve during artificial heart circulation.

Animals↗
PubMed1999

Concealed hypothyroidism in patients with myeloperoxidase antineutrophili cytoplasmic autoantibodies- (MPO-ANCA) positive renal disease.

AIM: To elucidate the relationship between thyroid disorders and myeloperoxidase (MPO) antineutrophili cytoplasmic autoantibodies-(ANCA) positive renal disease, we investigated the prevalence of thyroid diseases in patients with them. SUBJECTS AND METHODS: The subjects consisted of 10 patients (6 males and 4 females) diagnosed as having MPO-ANCA-positive renal disease in our hospital. To evaluate thyroid function, serum thyroid-stimulating hormone (TSH) and free-thyroxine (FT4) levels were measured by a immunoradiometric assay (IRMA) and a radioimmunoassay (RIA), respectively. Thyroid autoantibodies against microsomal antigen and thyroglobulin were measured by means of particle agglutination. In addition, antibodies against thyroid peroxidase (TPO-Ab) and purified thyroglobulin (Tg-Ab) were also determined by RIA. To assess the disease activity, we employed Birmingham Vasculitis Activity Score (BVAS). RESULTS: The results were that 4 out of 10 patients (40%) were accompanied by hypothyroidism, including 2 patients with subclinical hypothyroidism and I during thyroid hormone replacement therapy. The BVAS of the hypothyroidism group (group A) was significantly lower (p < 0.05) than that of non-hypothyroidism group (group B), 18.5 +/- 9.0 (mean +/- SD) versus 24.2 +/- 16.6. MPO-ANCA titers were not significant between the two groups, 376.8 +/- 316.8 EU versus 311.5 +/- 203.6 EU. CONCLUSION: Thyroid disorder, especially hypothyroidism would not be a rare complication in patients with MPO-ANCA-positive renal disease. We should concentrate more on thyroid lesion in them.

Aged↗
PubMed1999

[Adhesion therapy for malignant pleural effusion (intrapleural administration of OK-432 with minocycline)].

Eleven patients with massive effusion due to pleuritis carcinomatosa were treated by tube drainage, followed by instillation of OK-432 and minocycline for pleurodesis. Pleural immunological and chemical reactions of adhesion were strongly induced by the use of these adhesive agents. As a result, pleural effusion was diminished in all patients without recurrence, allowing the drainage tubes to be successfully removed. As severe adverse effects following this course of therapy, high fever was observed in all patients, and acute renal failure in one. Blood chemical data from the patients revealed an increase in the number of granulocytes with a high level of interleukin-6 one day after instillation. These findings suggested that the symptoms of general inflammation were induced by local pleural inflammation. The median survival period was 253.7 days for 5 patients who were sufficiently fit to be discharged from our hospital. This was better than the historical average for the patients with uncontrolled pleural effusion. In conclusion, it was possible to control malignant pleural effusion and achieve longer survival periods through the optimal management of tube drainage and instillation of adhesion-inducing agents.

Aged↗
PubMed1999

Microsatellite instability and loss of heterozygosity in primary and secondary proliferative lesions of the parathyroid gland.

Clonality and genetic abnormalities were evaluated to characterize proliferative lesions of the parathyroid gland. Fourteen lesions from patients with single-gland proliferation (adenomas [PA]), 6 lesions from patients with multiple-gland proliferation (primary hyperparathyroidism [PHPT]), and 47 lesions from 16 patients with secondary hyperparathyroidism (SHPT) were examined. Based on the X chromatin inactivation pattern, which was revealed by a HUMARA assay of lesions from female patients (n = 34; 24 informative cases), monoclonality was demonstrated in 6 of 10 PA (60%), 2 of 5 PHPT (40%), and 6 of 9 SHPT lesions (14 of 27 lesions, 52%). By PCR analysis using 17 microsatellite markers on eight chromosomes (chromosomes 1, 2, 3, 5, 6, 11, 13, and 17), loss of heterozygosity was sporadically observed in 4 of 14 PA, 3 of 6 PHPT, and 7 of 47 SHPT lesions, in most cases on a single locus of chromosome 11. On the other hand, microsatellite instability was observed more frequently: ie, in six PA, five PHPT, and nine SHPT lesions. The profile of microsatellite instability depended on the type of proliferation: microsatellite instability (MI) seemed to cluster in the region of chromosome 11 in PA. Microsatellite instability on TP53 was observed in 3 of 6 PHPT lesions and in 2 of 47 SHPT lesions but in no PA lesions. Microsatellite instability on Mfd47 was observed in only some cases of SHPT. Although no significant correlation was identified among histologic features, clonality, and genetic abnormalities in cases of primary proliferation, genetic abnormalities were more frequently observed in SHPT lesions that lacked fat tissues. Thus, genetic instability might be important in proliferative disorders of the parathyroid gland, either with or without uremia. However, genetic instability seems to be induced by different mechanisms in the three types of proliferation studied. In SHPT, the absence of fat tissues may indicate that the proliferation is accompanied by genetic changes.

Adenoma↗
PubMed1999

[Factor VII].

Explore the source record for details and available documents.

Factor VII↗
PubMed1999

[Metabolism of 123I-FP-CIT in humans].

The metabolism of N-(3-fluoropropyl)-2 beta-carbomethoxy-3 beta-(4-iodophenyl)nortropane (123I) (123I-FP-CIT) in healthy humans was studied. Plasma and urine samples, obtained after i.v. administration of 123I-FP-CIT, were analyzed using the two-dimensional thin-layer chromatography technique. Eleven radiochemical components were detected in both plasma and urine, and four of them were the parent 123I-FP-CIT and its metabolites, N-(3-fluoropropyl)-2 beta-carboxy-3 beta-(4-iodophenyl)nortropane (123I) (123I-acid), 2 beta-carboxy-3 beta-(4-iodophenyl)nortropane (123I) (123I-nor-acid) and 2 beta-carbomethoxy-3 beta-(4-iodophenyl)nortropane (123I) (123I-nor-CIT). These four identified radiochemical components occupied about 80% or more in ratio of the radiochemical components in the plasma and urine. In the metabolites of 123I-FP-CIT, the high polar metabolites--123I-acid and 123I-nor-acid--were found to be the major components, while lipophilic 123I-nor-CIT was a minor component. Free iodide (123I-) was not found in the plasma or urine. Thus, the main metabolic reactions which 123I-FP-CIT undergoes in humans seem to be hydrolysis of the ester bond and N-dealkylation. In vivo deiodination of 123I-FP-CIT was found to be minimum. Current results suggest that the metabolites of 123I-FP-CIT hardly influence evaluation of the dopamine transporter in the human brain.

Adult↗
PubMed1999

Dual action of nitric oxide in pathogenesis of indomethacin-induced small intestinal ulceration in rats.

We investigated the pathogenic role of nitric oxide (NO) in indomethacin-induced intestinal ulceration in rats. Nonfasting animals responded to a single administration of indomethacin (10 mg/kg, s.c.), resulting in multiple hemorrhagic lesions in the small intestine, mostly the jejunum and ileum. The damage was first observed 6 hr after indomethacin, the severity increasing progressively with time up to 24 hr later, accompanied with the gene expression of inducible NO synthase (iNOS) and the increase of nitrite and nitrate (NOx) contents in the mucosa. The ocurrence of damage was significantly prevented when iNOS induction was inhibited by dexamethasone given either once 0.5 hr before or twice 0.5 hr before and 6 hr after indomethacin. Likewise, aminoguanidine (a relatively selective iNOS inhibitor) reduced the severity of damage, irrespective whether given twice or as a single injection 6 hr after indomethacin. By contrast, the non-selective NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) exhibited a biphasic effect, depending on the time of administration; the pre-administration worsened the damage, while the later administration reduced the severity of these lesions, yet both responses occureed in a L-arginine-sensitive manner. Pre-administration of L-NAME, but not aminoguanidine, significantly decreased NOx production in the intestinal mucosa of normal rats, while the increase of NOx production following indomethacin was significantly suppressed by the later administration of aminoguanidine as well as L-NAME. These results suggest that NO exerts a dual action in the pathogenesis of indomethacin-induced intestinal ulceration; NO generated by cNOS is protective against indomethacin, by maintaining the integrity of intestinal mucosa, while NO derived by iNOS plays a key pathogenic role in the ulcerogenic process.

Animals↗
PubMed1999

[Synthesis of 18F-FDG with FDG MicroLab system: basic studies for clinical application].

We synthesized 18F-FDG by using an automated synthetic apparatus "FDG MicroLab" (GE Medical Systems) which produces 18F-FDG by a solid phase 18F-fluorination. Its quality and reproducibility were evaluated in order to assess feasibility of the apparatus for routine clinical production of 18F-FDG. For 5 consecutive 18F-FDG synthesis, target irradiation was carried out at 15 microA for 60 min. 18F-FDG was obtained in 50 min after EOB with an end-of-synthesis yield of 9.34 +/- 1.06 GBq. Radiochemical yield and radiochemical purity were 47 +/- 3% (decay corrected) and 98.0 +/- 0.5%, respectively. Other several quality control parameters tested conformed with "Standards of Compounds Labeled with Positron Nuclides" (RADIOISOTOPES, 44, 1995). Thus, the automated synthetic apparatus "FDG MicroLab" has proven to stably produce 18F-FDG with high yield and high purity. The apparatus is feasible for routine clinical production of 18F-FDG.

Chemical Phenomena↗
PubMed1999

An experience of pubic hair reconstruction using free temporoparietal fasciocutaneous flap with needle epilation.

Lack of pubic hair may cause suffering for pubescent and adult patients; thus, rapid and precise reconstruction is required for their mental health. We reported pubic hair reconstruction for burn alopecia using a free temporoparietal fasciocutaneous flap transfer with needle epilation. Fourteen months after the reconstruction, an acceptable aesthetic result was obtained, and our patient is satisfied with her reconstructed pubic hair. We conclude that reconstruction using a free temporoparietal fasciocutaneous flap with needle epilation is a useful method for selected patients.

Adult↗
PubMed1999

Expression of multidrug resistance-related genes does not contribute to risk factors in newly diagnosed childhood acute lymphoblastic leukemia.

BACKGROUND: The present study was designed to evaluate the association of multidrug resistance gene (MDR1), multidrug resistance-associated protein (MRP) gene and lung resistance protein (LRP) gene expression (mRNA levels) with risk factors such as phenotype, age and leukocyte count in newly diagnosed childhood acute lymphoblastic leukemia, because biological mechanisms contributing to risk factors were not known. METHODS: Expression of the MDR1, MRP and LRP genes in leukemic cells from 40 pediatric patients was quantitated using the reverse transcriptase polymerase chain reaction method. The associations of expression of these genes with age and leukocyte count, which are known as risk factors for acute lymphoblastic leukemia (ALL), were analyzed. Moreover, the associations with clinically classified risk-related groups (high-risk ALL and low-risk ALL) were also investigated. RESULTS: No positive correlations between expression of these genes and age or leukocyte count were found. The expression of these genes was not different among clinically classified risk-related groups. CONCLUSIONS: Expression (mRNA levels) of the MDR1, MRP and LRP genes did not contribute to risk factors in newly diagnosed childhood acute lymphoblastic leukemia.

Adolescent↗
PubMed1999

[Human apolipoprotein B48 receptor].

Unique candidate receptor membrane binding proteins, MBP 200 and 235, were identified in human monocyte-macrophages. The MBP binds and internizes chylomicrons, triglyceride (TG)-rich VLDL, and VLDL devoid of apo E, but not acetyl LDL, via a domain in apo B48. The MBP is named apo B48 receptor because the receptor-binding domain is within apo B48. The apo B48 receptor differs from the scavenger receptor family and LDL receptor family because it does not bind acetyl LDL and it binds VLDL devoid of apo E by an apo E-independent mechanism. Immunohisto-chemical studies indicate colocalization of anti-apo B48 receptor Ab and monocyte-macrophage specific Ab in human atherosclerotic lesion foam cells. This suggests that apo B48 receptor may contribute to foam cell formation and atherosclerosis in abnormal state with elevated TG-rich lipoproteins.

Arteriosclerosis↗
PubMed1999

Effect of glycated low density lipoprotein on smooth muscle cell proliferation.

BACKGROUND: We investigated the effect of glycated low density lipoprotein (LDL) on smooth muscle cell proliferation. METHODS: Blood was drawn from 6 healthy subjects after overnight fasting. Native LDL was obtained by separating LDL from the samples with sequential ultracentrifugation. Glycated LDL was prepared by glycating the native LDL in vitro. Native and glycated LDL were added to a medium containing cultured porcine coronary artery smooth muscle cells, and the change in cell proliferation was examined after 24, 48, 72, and 96 hs. The cells were counted using a cell counting kit (Dojin Chemical Co., Ltd.). RESULTS: There was no significant difference in the cell count between the control group, in which only PBS was added, and the native LDL group. However, cell proliferation was appreciably higher in the glycated LDL group than in the native LDL group. The mean total cell count at 24, 48, 72 and 96 hs was significantly higher (p<0.01) in the glycated LDL group (median: 0.843; range: 0.576-1.060) than in the native LDL group (median: 0.541; range: 0.282-0.683). CONCLUSIONS: These findings suggest that glycated LDL induces significantly greater acceleration of smooth muscle cell proliferation than does native LDL. Therefore, the acceleration of smooth muscle cell proliferation requires modification of LDL.

Animals↗
PubMed1999

Theoretical background for inward rectification.

Theoretical background has been reviewed for inward rectification due to a potassium current termed IRK. The Eyring rate theory in which the thermodynamic rate coefficient for chemical reactants (channels and ions in this case) can be described in terms of energy barriers for potassium ions can mimic not only the polarity and degree of rectification but also the voltage-dependence of the barium-induced IRK block. The model predicts that the blocking site locates 30-70% depth from the outer margin of the IRK channel.

Animals↗
PubMed1999

Histochemistry of Ki-67 antigen in ameloblastomas.

The proliferative potential of two common histologic variants of ameloblastoma was investigated immunohistochemically using Ki-67 antibody on routinely processed, formalin-fixed, paraffin-embedded sections. Thirty cases of ameloblastomas (15 cases of follicular and 15 cases of plexiform type) were analyzed. Autoclave heating pretreatment was employed at 121 degrees C for 20 min prior to analysis. This retrieval method allowed immunoreactive sites of the Ki-67 antigen to become exposed and thus available for immunohistochemical reaction. We found that expressed Ki-67 antigen was localized within the nucleus of tumor cells in both follicular and plexiform ameloblastomas. Immunoreactive cells were localized in the peripheral area of tumor islands as well as in the central stellate reticulum-area. The labeling rate was higher in the plexiform (3.68%) than in the follicular type (1.78%). Results suggest that cell proliferation of ameloblastoma was different depending on histologic variation of the tumor. Further, the proliferative potential was higher in the plexiform ameloblastoma than that in the follicular type.

Adolescent↗
PubMed1999

Correlation of E-cadherin and alpha-catenin expression with differentiation of oral squamous cell carcinoma.

The precise mechanism of disruption of cell-cell adhesion in oral squamous cell carcinomas has yet to be established. We therefore sought to clearly this mechanism by investigating expression of both E-cadherin (E-CD) and alpha-catenin (alpha-CAT), which is an intracellular CD-binding molecule, in squamous cell carcinomas of the tongue, gingiva and floor of the mouth using immunohistochemical and immunoblotting techniques. We found that reduced expression of both E-CD and alpha-CAT occurred more frequently in moderately- and poorly-differentiated carcinomas than in well-differentiated specimens (p < 0.001), and this reduced expression showed no regional specificity. Relatively frequent loss of alpha-CAT expression in poorly-differentiated carcinomas was detected by both immunohistochemical and immunoblotting analyses. These findings suggest that E-CD and alpha-CAT are both important regulators of intercellular adhesion, and that the reduction of these molecules is also linked to the process of tumor dedifferentiation.

Antibodies, Monoclonal↗
PubMed1999

The Arabidopsis dwf7/ste1 mutant is defective in the delta7 sterol C-5 desaturation step leading to brassinosteroid biosynthesis.

Lesions in brassinosteroid (BR) biosynthetic genes result in characteristic dwarf phenotypes in plants. Understanding the regulation of BR biosynthesis demands continued isolation and characterization of mutants corresponding to the genes involved in BR biosynthesis. Here, we present analysis of a novel BR biosynthetic locus, dwarf7 (dwf7). Feeding studies with BR biosynthetic intermediates and analysis of endogenous levels of BR and sterol biosynthetic intermediates indicate that the defective step in dwf7-1 resides before the production of 24-methylenecholesterol in the sterol biosynthetic pathway. Furthermore, results from feeding studies with 13C-labeled mevalonic acid and compactin show that the defective step is specifically the Delta7 sterol C-5 desaturation, suggesting that dwf7 is an allele of the previously cloned STEROL1 (STE1) gene. Sequencing of the STE1 locus in two dwf7 mutants revealed premature stop codons in the first (dwf7-2) and the third (dwf7-1) exons. Thus, the reduction of BRs in dwf7 is due to a shortage of substrate sterols and is the direct cause of the dwarf phenotype in dwf7.

Alleles↗
PubMed1998

Prediction of the coding sequences of unidentified human genes. XII. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro.

In this paper, we report the sequences of 100 cDNA clones newly determined from a set of size-fractionated human brain cDNA libraries and predict the coding sequences of the corresponding genes, named KIAA0819 to KIAA0918. These cDNA clones were selected on the basis of their coding potentials of large proteins (50 kDa and more) by using in vitro transcription/translation assays. The sequence data showed that the average sizes of the inserts and corresponding open reading frames are 4.4 kb and 2.5 kb (831 amino acid residues), respectively. Homology and motif/domain searches against the public databases indicated that the predicted coding sequences of 83 genes were similar to those of known genes, 59% of which (49 genes) were categorized as coding for proteins functionally related to cell signaling/communication, cell structure/motility and nucleic acid management. The chromosomal locations and the expression profiles of all the genes were also examined. For 54 clones including brain-specific ones, the mRNA levels were further examined among 8 brain regions (amygdala, corpus callosum, cerebellum, caudate nucleus, hippocampus, substantia nigra, subthalamic nucleus, and thalamus), spinal cord, and fetal brain.

Amino Acid Sequence↗