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Biomedical subjects

T Takano

Publications and source records attributed to T Takano.

At least 289 records · Page 16Linked to original sources

Increased expression of CD44 variants in differentiated thyroid cancers.

Expression of CD44 variants in thyroid tumors was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) with a fluorescent image analyzer. Increased expression of CD44 variants compared with normal thyroid tissues was observed in most thyroid follicular tumors, especially in follicular carcinomas, poorly differentiated papillary carcinomas and some follicular adenomas. However, variants were hardly detectable in an anaplastic carcinoma. Analysis with restriction enzymes revealed that the major PCR product, consisting of variant bands, was derived from CD44E. Therefore, the expression of CD44E may be associated with the proliferation of differentiated thyroid cells.

Adenocarcinoma, Follicular↗

Developmental changes in electroencephalogram for term and preterm infants using an autoregressive model.

The purpose of the present study was to clarify the developmental changes of electroencephalogram (EEG) background activity in term and preterm infants that take place with increasing conceptional age (CA) through an autoregressive (AR) model. Polygraphical EEG recordings were obtained from 76 healthy term and preterm infants with a CA ranging between 31 and 40 weeks. Decreases in total power and component power of delta were noted with CA during burst activity (BA) in quiet sleep (QS) and during active sleep (AS). Increases in total power and component power of delta were noted with CA during interburst interval activity (IBIA) of QS. Regression analysis (RA) of the information amount (IA) indicated a negative correlation with increasing CA in AS and in the monopolar EEG tracings Fp1, C3, O1 and O2 in BA, and a positive correlation in O1 in IBIA. Regression analysis of the IA of delta indicated a negative correlation with increasing CA in AS and in Fp1, C3, O1 and O2 in BA, and a positive correlation in O1 in IBIA. Regression analysis of the IA of delta indicated a negative correlation with increasing CA in BA and AS. These results showed that the high voltage slow wave component changed to a low voltage slow one with development in AS and that BA was longer in duration and lower in power with increasing CA, while IBIA was shorter in duration and higher in power. In conclusion, significant developmental changes occur in all derivatives of AS. Even though the EEG of BA and IBIA change separately, they are followed by EEG of QS in a continuous pattern.

Electroencephalography↗

Identification of carriers of Duchenne/Becker muscular dystrophy by a novel method based on detection of junction fragments in the dystrophin gene.

We developed a Southern blotting based method that uses rare cutting restriction endonucleases and electrophoresis of single stranded DNA to detect junction fragments resulting from the rearranged dystrophin gene. By conventional Southern blot hybridisation, no junction fragments were detected in 27 unrelated patients with Duchenne (DMD) or Becker (BMD) muscular dystrophy, who had 20 deletions and seven duplications in the dystrophin gene. With our new method, junction fragments were detected in 21 of these 27 patients. When the junction fragments were used as markers, five carriers were unequivocally diagnosed among six females from two families of DMD/ BMD patients. This novel method allows simple and definitive identification of carriers with risk factors for DMD/BMD without using quantitative Southern blot hybridisation.

Blotting, Southern↗

Induction of mcl1/EAT, Bcl-2 related gene, by retinoic acid or heat shock in the human embryonal carcinoma cells, NCR-G3.

NCR-G3 cells were established from a testicular embryonal carcinoma and were differentiated into multi-lineages including trophectoderm cells by exposure to retinoic acid. The differentiated cells began to produce human chorionic gonadotropin (hCG), a trophectoderm-specific hormone, which was regulated at the mRNA level. As we assumed that genes responsible for differentiation were differentially expressed at the early stage of retinoic acid-induced differentiation, we prepared a cDNA library from retinoic acid-treated NCR-G3 cells. This cDNA library was then screened for genes whose expression was induced during the differentiation of these cells. From about 5 x 10(4) clones screened, three independent sequences were isolated. Sequencing analysis revealed that clone 1002 codes for mcl1/EAT, which has a Bcl-2 homology domain. The expression of mcl1/EAT, the Bcl-2 related gene, was increased at an early stage of the retinoic acid-induced differentiation and preceded the up-regulation of cytokeratin and hCG genes after ratinoic acid treatment. Furthermore, mcl1/EAT was also up-regulated by heat shock, which has recently been shown to induce the cells to differentiate.

Biomarkers↗

Pathophysiological analysis of serum troponin T release kinetics in evolving ischemic myocardial injury.

The present study measured cardiac troponin T(TnT) for the pathophysiological analysis of evolving ischemic myocardial injury in 35 patients with unstable angina (3: Class IB, 32: Class IIIB) and in 40 patients undergoing coronary reperfusion therapy for acute myocardial infarction. Serum TnT, creatine kinase (CK), CKMB, myoglobin (Mb), and myosin light chain 1 (MLC1) were measured every 2-24 h for 10 days after admission to the CCU. In patients with unstable angina, positive test results were detected in 65.7% for TnT, 20% for CK, 37.1% for CKMB, 60.9% for Mb, and 26% for MLC1. Of the 23 patients with positive TnT, 12 (52.2%) had cardiac events. Of the 12 patients with negative TnT, 11 (91.6%) were event-free. All of the patients who developed cardiac events showed a persistent (n = 10) or delayed elevation (n = 2) pattern 28-120 h beforehand. The sensitivity for predicting cardiac events was 92.3% for TnT, 80% for Mb, 53.8% for CKMB, and 50% for MLC1. In patients with acute myocardial infarction, TnT release kinetics showed 2 peaks after coronary reperfusion therapy. TnT values at the 1st peak significantly correlated with maximum CKMB (r = 0.70, p < 0.05) and early-stage left ventricular wall motion score (r = 0.60, p < 0.05), while 2nd-peak TnT values significantly correlated with maximum MLC1 (r = 0.59, p < 0.05), the T1-SPECT score (r = 0.78, p < 0.05) and left ventricular ejection fraction (r = -0.74, p < 0.05) in the convalescent stage. The 2nd/1st-peak TnT ratio significantly correlated with the nQ/nST elevation index (ratio of the number of leads developing abnormal Q-wave 1 week after the onset to the number of leads showing ST elevation of more than 1 mm at admission) (r = 0.63, p < 0.05) in patients with anterior myocardial infarction. These data indicate that persistent release of TnT reflects progressive irreversible myocardial damage in unstable angina and indicates a risk of future cardiac events. In acute myocardial infarction, the 2nd/1st-peak TnT ratio in patients undergoing coronary reperfusion therapy may be useful for the quantitative evaluation of myocardial salvage.

Acute Disease↗

Isolation and characterization of a plasmid from Lactobacillus helveticus CP53.

A plasmid, pCP53 (11.5 kilo base pairs long), was isolated from Lactobacillus helveticus CP53 and its restriction map was constructed. A chimeric plasmid, pCP53D (4.7 kb), which had a 2.0-kb HindIII fragment from pCP53 and a tetracycline resistance (Tc) gene from Streptococcus faecalis replicated and expressed tetracycline resistance in Lactobacillus casei CP680. Fifteen strains of L. helveticus were transformed with pCP53D by electroporation and selected for Tc resistance. Transformants were obtained from two out of 15 host strains, L. helveticus CP611 and CP791, with 5 x 10(3) and 50 transformants per microgram of DNA, respectively.

DNA, Bacterial↗

Decrease of tissue angiotensin I-converting enzyme activity upon feeding sour milk in spontaneously hypertensive rats.

Blood pressure increases were inhibited by feeding a diet containing sour milk fermented by a starter containing Lactobacillus helveticus and Saccharomyces cerevisiae to spontaneously hypertensive rats. In rats fed with the sour milk, the angiotensin I-converting enzyme activity of the aorta was significantly lower than that of rats fed with the control commercial diet.

Angiotensin-Converting Enzyme Inhibitors↗

TGF-beta 1 inhibits the cell proliferation stimulated by IGF-I by blocking the tyrosine phosphorylation of 175kDa substrate.

TGF-beta strongly inhibits the mitogenic effect of growth factors such as insulin-like growth-I (IGF-I) on thyroid follicular cells. To study the mechanism of this inhibiting action, the effect of TGF-beta 1 on tyrosine phosphorylation of 175kDa substrate induced by IGF-I was investigated in FRTL-5 thyroid epithelial cells. After treatment with TGF-beta 1, tyrosine phosphorylation of 175kDa protein induced by IGF-I was inhibited in parallel with the degree of the inhibition of cell proliferation. However, TGF-beta 1 had no effect on tyrosine phosphorylation of 120kDa substrate. These results suggest that TGF-beta 1 blocks the mitogenic signal of IGF-I by inhibiting the tyrosine phosphorylation of 175kDa substrate in FRTL-5 cells.

Animals↗

Identification of an antihypertensive peptide from casein hydrolysate produced by a proteinase from Lactobacillus helveticus CP790.

Casein hydrolysate, produced by an extracellular proteinase from Lactobacillus helveticus CP790, was fractionated by two-step reverse-phase HPLC. Only one fraction showed antihypertensive activity as measured by systolic blood pressure in spontaneously hypertensive rats after oral administration. Ten peptides in the fraction were further purified and identified by analysis of amino acid sequences. Each identified peptide was chemically synthesized, and the antihypertensive activity of each peptide was evaluated in spontaneously hypertensive rats. The synthetic peptide with a sequence of Lys-Val-Leu-Pro-Val-Pro-Gln, found in beta-casein, indicated strong antihypertensive activity from 2 to 10 h after oral administration of 2 mg of peptide/kg of BW, and the effect was maximal at 6 h after oral administration (-31.5 +/- 5.6 mm Hg). Moreover, the antihypertensive effect of the peptide was dependent on the dosage of peptide from 0.5 to 2 mg of peptide/kg of BW. Interestingly, the antihypertensive peptide showed lower inhibitory activity of angiotensin I-converting enzyme, but the activity was increased after pancreatin digestion.

Amino Acid Sequence↗

Characterization of vitronectins in atherosclerotic lesions.

Vitronectin is one of the major extracellular matrix proteins that accumulates in atherosclerotic lesions. A monoclonal antibody (EMR1a/212D) specifically stained the extracellular regions in thickened intima which colocalized well with lipid deposition. The antigenic glycoprotein with a molecular weight of 66KDa was revealed to be rabbit vitronectin. When homogenates of WHHL rabbit atheroma were subjected to immunoblot analysis using EMR1a/212D, four molecules with molecular weight 66, 56, 50 and 47KDa were detected. To confirm whether these smaller immunopositive bands were derived from mature vitronectin, another monoclonal antibody (EMR1b/244H) recognizing the polypeptide region of vitronectin was prepared. All four molecules were detected by EMR1b/244H as well as by EMR1a/212D. Two smaller vitronectins (56KDa and 50KDa) were found in atherosclerotic lesions and increased markedly during the development of atherosclerosis. On the other hand, the vitronectin detected in normal rabbit aorta was mainly of the mature type, while 56KDa and 47KDa forms were not detected. The total amount of the four vitronectins in atherosclerotic lesions was 38.5 +/- 5.0 ng/mg wet weight tissue, a value approximately 9.5 fold higher than that found in normal aorta. In conclusions, we found massive accumulation of these vitronectins concomitant with atherosclerotic development in rabbit aorta.

Animals↗

[Perioperative management for partial resection of a lymphangioma of the tongue].

Twelve month old boy had been suffering from a neck lymphangioma. Partial resection was carried out in his newborn period at another hospital, and he was obliged to be tracheostomied because of severe airway obstruction due to postoperative edema. He was scheduled for partial glossectomy since his tongue had increased in mass, which could easily be injured by teeth, and he had difficulties in swallowing recently. His airway was not obstructive even during sleep and preoperative MRI showed adequate space around the larynx. We induced anesthesia by a mask and he was subseqently intubated with a fiberscope via his nose because his huge and less mobile tongue could not allow the insertion of a laryngoscope and this might cause bleeding. We did not extubate the endotracheal tube for fear of airway obstruction attributable to postoperative edema. Marked edema around the neck persisted longer than we expected. We tried to evaluate the degree of diminution of edema with MRI twice to decide when extubation could be attempted. However, examination with MRI could not give us useful informations. Consequently we evaluated the timing of extubation by examining whether he could close his mouth or not, whether his tongue could move freely and the degree of edema. We realized lymphangioma caused marked and extensive edema after the operation and we should keep in mind that lymphangioma of the tongue might cause various anesthetic problems especially on airways.

Anesthesia, Inhalation↗

[A case report of transaortic mitral valve replacement in Marfan's syndrome].

One-stage operation was successfully performed in 30-year-old male with annulo aortic ectasia and mitral valve regurgitation secondary to Marfan's syndrome. The replacement of the mitral valve was performed through aortic root. The transaortic mitral valve replacement employed here should prove useful for similar cases requiring reconstruction of aortic root and replacement of mitral valve simultaneously in Malfan's syndrome.

Adult↗

Sensitive detection of oxidatively modified low density lipoprotein using a monoclonal antibody.

We have established a new method capable of measuring the very low concentrations of oxidized low density lipoprotein (OxLDL). In our previous study, we obtained a novel murine monoclonal antibody against oxidized lipoproteins (Itabe, H. et al. 1994. J. Biol. Chem. 269: 15274-15279). The epitope of this antibody resides in oxidized products of phosphatidylcholine that can form complexes with polypeptides, including apolipoprotein B. When the monoclonal antibody was precoated onto microtiter wells prior to carrying out a sandwich ELISA using an anti-human apolipoprotein B antibody, it was possible to detect 0.5 ng protein of copper-induced OxLDL. The detection of OxLDL was dependent on the presence of monoclonal antibody and was blocked by oxidized phosphatidylcholine (OxPC). Under the same sandwich ELISA condition, native LDL showed a dose-dependent increase of absorbance that was inhibited by complex of OxPC with BSA. These results suggest the possible occurrence of oxidative modification of human plasma LDL, which is recognized by the antibody against OxPC. The level of LDL oxidation of normal human subjects was found to be 0.52 +/- 0.35 units per 5 mu g protein of LDL, where one unit was defined as the reactivity corresponding to 1 ng of copper-induced OxLDL by this assay. Furthermore, we found that the LDL oxidation level in patients who had been receiving hemodialysis treatment was increased more than eightfold over that of normal subjects. We suggest that LDL in human plasma is oxidatively modified under certain conditions and this method for measurement of OxLDL could be used to study the relationship between in vivo oxidation reaction and various pathological conditions.

Antibodies, Monoclonal↗

[What do adolescents desire for the postoperative pain relief?--a speculation from an interview with a patient].

Three different methods of postoperative pain management were evaluated by a 16 year old girl within 1 month after the last surgery who had undergone intrathoracic surgery three times during the six months. The postoperative pain management was different after each surgery. The first bullectomy was performed under thoracoscopy and she did not complain of severe pain with nerve blocks and NSAID suppository. After the second and third intrathoracic surgery, postoperative pain relief was tried with iv PCA and epidural morphine respectively. Although she commented that epidural morphine had been more potent than i.v. PCA from the viewpoint of pain relief, she preferred i.v. PCA to bolus administered epidural morphine because she could always control her pain whenever pain relapsed. Bolus epidural morphine, however, was administered by physicians only, and she endured severe pain for more than two hours until the next dose at the midnight of the operation. That might be the reason why she was not satisfied with epidural morphine. It was concluded that we should try to offer not fluctuating analgesic level but readily available potent analgesics which could be hopefully administered by patients themselves in adolescent or adult population.

Adolescent↗

[Injury to ascending aorta by cross-clamp--histologic evaluation].

To evaluate the injury to ascending aorta by cross-clamp, the trauma to the vessel wall was examined microscopically and the occlusive intensity of the vascular clamp was measured. Six patients were underwent total replacement of the ascending aorta and the aortic arch for aortic dissection. The ascending aorta and the aortic arch were resected during operation, the clamped regions of the ascending aorta were cut into the four pieces (the distal site, two part of the medial site, the proximal site applied by the vascular clamp) after operation. The four pieces of the ascending aorta were examined microscopically. The occlusive intensity of the vascular clamp were measured at the distal site, the medial site, and the proximal site by the load-measuring scale. The trauma to the vessel wall were classified to three degrees (grade 1 to grade 3). Grade 1 showed the minimal changes--narrowing of interstices between collagen fibers and muscle fibers in the media. Grade 2 showed the moderate changes--decrease of collagen fibers, atrophy and disruption of smooth muscle and elastic fiber in the media. Grade 3 showed the severe changes--disruption of the intima and defluvium of endothelial cells. The occlusive intensity of the vascular clamp were 1.0 kg at the distal site, 1.9 kg at the medial site and 3.6 kg at the proximal site, respectively. In the microscopic examinations, grade 1 changes were most frequent at the distal site, grade 1 and grade 2 changes were observed equally at the medial site, grade 3 change was observed only at the proximal site. The degree of the trauma to the vessel wall becomes severer in proportion to increase of the occlusive intensity of the vascular clamp.

Adult↗