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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 793 records · Page 44Linked to original sources
PubMed1992

Hemorrhagic myocardial infarction after reperfusion detected by X-ray CT--experimental and clinical study.

The purpose of this study was to determine whether computed tomography (CT) can detect hemorrhagic infarction occurring after intracoronary thrombolytic therapy (ICT) for acute myocardial infarction (AMI). In an experimental study, 12 dogs underwent 2-4 h of left anterior descending artery (LAD) occlusion, followed by reperfusion, and infusion of contrast material into the LAD. After CT examination, the heart was cut into transverse sections. A good correlation was obtained between the CT-enhanced area and the hemorrhagic area in the sliced heart section (r = 0.895, p less than 0.001). In a clinical study, we applied CT immediately after ICT in 25 patients with AMI. In 13 of 25 patients, the CT showed post-ICT myocardial enhancement areas. To evaluate the relationship of the enhancement areas shown by CT to the viability of the myocardium, we compared enhancement areas by CT with the corresponding perfusion defect areas of Thallium-201 imaging (SPECT) one month later. There was no significant correlation between the enhancement areas and perfusion defect areas (r = 0.38, p greater than 0.1). The SPECT defect areas were consistently smaller than the CT enhancement areas. These results indicate that CT can detect hemorrhage into the myocardium after ICT, and that after ICT half the AMI patients showed hemorrhagic infarction. However, hemorrhage did not cause complete deterioration of the myocardium.

Adult↗
PubMed1992

Enhancing effect of sodium chloride on in vitro adsorption of paraquat onto activated carbon.

The enhancing effect of sodium chloride addition on the adsorption of paraquat onto activated carbon was discussed from the standpoints of equilibrium amount adsorbed and adsorption rate in vitro. The amount of paraquat adsorbed was increased by the addition of sodium chloride. The amount adsorbed with 0.1% addition was about five times greater than that in sodium chloride-free solution at an equilibrium concentration of 1 mg/L. The adsorption rate of paraquat onto activated carbon was also accelerated by sodium chloride addition. Kinetic constants in 0.1% and 0.9% sodium chloride solution were about 1.4 and 2.0 times greater, respectively, than that in sodium chloride-free solution. It was confirmed that paraquat removal by activated carbon was enhanced by sodium chloride addition. The reason was assumed to be the interrupted dissociation of paraquat in solution caused by sodium chloride addition.

Adsorption↗
PubMed1992

Immunohistochemical localization of 17 alpha-hydroxylase/C17-20 lyase and aromatase cytochrome P-450 in the human ovary during the menstrual cycle.

Immunohistochemical localization of 17 alpha-hydroxylase/C17-20 lyase (P-450(17 alpha,lyase)) and aromatase cytochrome P-450 (P-450arom) in normal human ovaries during the menstrual cycle was studied using specific polyclonal antibodies which were raised against corresponding enzymes. In the follicular phase of matured follicles, P-450(17 alpha,lyase) was localized in theca interna cells and P-450arom in granulosa cells. P-450(17 alpha,lyase) was expressed in theca interna cells before P-450arom was expressed in granulosa cells. The corpus luteum showed immunoreactivity to both enzymes and, after menstruation, immunoreactivity decreased gradually until it could not be detected in the corpus albicans. In corpus luteum graviditatis the immunoreactivity continued to be expressed strongly. In some atretic follicles, P-450(17 alpha,lyase) and/or P-450arom continued to be expressed. In the stromal layer, P-450(17 alpha,lyase was detected in secondary interstitial cells, which originated from the theca interna of atretic follicles, and P-450arom was detected in hilar cells. Immunoreactivity to both enzymes was also detected in oocytes of developing follicles. These results are consistent with the two cell theory in the human ovary. They also suggest that androgens and oestrogens are produced not only by follicles and corpora lutea but also by stroma and oocytes.

Adult↗
PubMed1992

Measurement of regional evaporation rate from skin surface by evaporimeter.

The present study was conducted to confirm the validity of an evaporimeter and its measuring condition prior to applying it to the field of clothing physiology, especially for measuring the amount and distribution of the evaporation rate over the human body surface. After calibration of the evaporimeter according to the manufacture's specification, it was checked for its response time and the comparative assessments of the evaporation rate from the skin. The quantitative examination of the evaporation rate in both in vitro water loss and in vivo the evaporation rate from the human skin, clarified that the observed values of evaporation rate were lower than water loss or weight loss of the human body. Although the evaporimeter is a useful device to measure the evaporation rate at regional parts of the human body under natural condition, an additional calibration by an actual in vitro measured water loss should be adopted for the accurate assessments of the evaporation rate.

Calibration↗
PubMed1992

[Subcutaneous fat distribution in Japanese women. Part 1. Fat thickness of the trunk].

The thickness of subcutaneous fat were measured at 215 different points on the trunk in Japanese young women with using B-mode ultrasonic device. Subjects were 10 healthy Japanese females aged from 20 to 24 years. Average subcutaneous fat thickness over the trunk of 10 subjects was 9.8 mm, and it's standard deviation was 1.5 mm. Subcutaneous fat thickness showed the higher value at the buttock, the breasts and the abdomen and the lower value at the back. The difference of fat distribution between obese subjects and lean subjects was exhibited mainly on the abdominal parts but not on the chest and back parts of the trunk.

Adipose Tissue↗
PubMed1992

Distribution of evaporation rate on human body surface.

Relative humidity (R. H), vapour pressure (Psk) and evaporation rate (Esk) of the human skin surface were measured at 29 points by an evaporimeter at 25 degrees C, 28 degrees C, 31 degrees C, 34 degrees C and 37 degrees C of air temperature (Ta), with 35 +/- 10 % R. H and air velocity of less than 0.2 m/s. The skin temperatures and the body weight loss were also measured by thermography and electronic balance. Ten healthy female subjects aged 22-34 years, wearing brassiere and shorts, took a supine and a prone posture during experiment. Comparisons of the obtained Esk with the previous results of other studies showed that there were no definite differences among the measuring methods of Esk, while it is ascertained that the calibration of the results to some standard values such as weight loss were more important to get accurate values of Esk. Distribution patterns of Esk were almost the same in the insensible zone but they remarkably changed in the sweating zone. According to the regression analysis of Esk and Ta, 29 regions were classified into the following 9 groups which showed similar values and changes of Esk with the air temperature: 1) face, 2) front upper trunk, 3) back upper trunk, 4) front lower trunk, 5) back lower trunk, 6) arm, 7) leg, 8) hand and foot and 9) palm, sole and axilla. These results were discussed in relation to the contributing factors such as the number and the capacity of the sweat gland, the regional skin temperature and the pressure-sweat response and also in relation to the skin wettedness.

Adult↗
PubMed1992

Effects of frequency and intensity of sound on cochlear blood flow.

Laser Doppler flowmetry demonstrates that loud sound induces a decrease of blood flow in the cochlea of the guinea pig. In this experiment, we observed the effects of frequency and intensity of sound on cochlear blood flow using 15 guinea pigs. In the first 5 guinea pigs, a Doppler probe was attached to the basal turn of the cochlea and sounds of 6, 7, 8, 9 and 10 kHz were delivered to the ear serially from lower to higher frequency, i.e. from 6 kHz to 10 kHz. In the next 5 guinea pigs, the sound was delivered from higher to lower frequency, i.e. from 10 kHz to 6 kHz. The sound intensity delivered to the ear was changed from lower to higher intensity (80 to 120 dB SPL by 10 dB width) at each frequency. In the last 5 guinea pigs, the blood flow in the basal, second, third, and fourth turns of the cochlea was measured at 120 dB SPL of 10 kHz. No change of blood flow was seen in the cochlear basal turn at 6 and 7 kHz up to 120 dB SPL, but a decrease of blood flow was found at 110 and 120 dB SPL at 8, 9, and 10 kHz. On the other hand, the sound of 120 dB SPL at 10 kHz induced a decrease of blood flow only in the basal turn of the cochlea. Our results suggest that there is a corresponding blood flow area which is sensitive to specific frequency in the cochlea.

Animals↗
PubMed1992

In vitro study of E. coli tRNA identity elements.

Various tRNA transcripts were constructed to study the identity elements of E. coli tRNAs (Arg, Lys, Ala, Trp, Thr, Gly, Ser, Asn, Cys, His). Anticodon are involved in the identity elements in these tRNA species except the case of tRNA(Ala) and tRNA(Ser). Especially, the second and third positions of the anticodon are the recognition sites of E. coli tRNA(Arg), tRNA(Lys) and tRNA(Thr) for their cognate aminoacyl-tRNA synthetases. Discriminator base is an identity determinant of the above examined tRNAs except tRNA(Thr) and tRNA(Ser). In some cases, acceptor stem (Thr, Gly, His) and variable pocket (Arg, Ala) are considered to be the recognition elements.

Amino Acids↗
PubMed1992

Serial changes of mitral flow pattern after percutaneous transvenous mitral commissurotomy--assessment of Doppler and two-dimensional echocardiography.

To evaluate the acute change in the mitral flow pattern, especially pressure half-time after percutaneous transvenous mitral commissurotomy (PTMC) and to investigate the factors influencing the mitral flow pattern, Doppler and two-dimensional echocardiographic studies were performed in 15 patients before and two, six, 10 and 24 hours and seven days after PTMC. Mitral valve area increased and the mean mitral pressure gradient decreased after PTMC (1.0 +/- 0.4 cm2 to 1.8 +/- 0.4 cm2; 11 +/- 6 mmHg, to 3 +/- 2 mmHg, p < 0.01). Pressure half-time also decreased two hours after surgery, from 292 +/- 70 msec to 176 +/- 48 msec (p < 0.01) and then gradually decreased to 140 +/- 47 msec within seven days of the procedure without remarkable changes in mitral valve area and the mean transmitral pressure gradient. Left atrial dimensions decreased and left ventricular end-diastolic dimensions gradually increased after PTMC (51 +/- 6 mm to 46 +/- 5 mm; 47 +/- 4 mm to 50 +/- 3 mm). The time course of this was similar to that of the pressure half-time. Further study, in which the changes in pressure half-time were evaluated within 30 minutes of PTMC in 17 patients, indicated that pressure half-time significantly decreased from 248 +/- 69 msec to 139 +/- 28 msec five minutes after balloon inflation, slightly increasing again after 30 minutes to 153 +/- 31 msec.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization↗
PubMed1992

[Clinical characteristics of pulmonary edema in patients with unstable angina].

To elucidate the clinical characteristics of pulmonary edema in unstable angina, 120 patients with unstable angina who admitted to the hospital within 6 hours after the onset of chest pain were studied. The criteria for the diagnosis of pulmonary edema included interstitial pulmonary edema and diffuse alveolar edema. Pulmonary edema was present in 24 patients. In these patients, the duration of chest pain was relatively longer, and the incidences of diabetes mellitus, emergency coronary revascularization and multiple-vessel coronary artery disease were higher than in those without pulmonary edema. In addition, in-hospital mortality rate in patients with pulmonary edema was higher than in those without it (21 vs 1%, p < 0.001), which is probably due to a large area of myocardial ischemia. For these patients, therefore, early diagnosis and appropriate therapy to save viable segments of the myocardium are mandatory.

Aged↗
PubMed1992

Remarkable improvement of activity by CAPD in a hemodialysis patient with a pseudotumor of the craniocervical junction.

Pseudotumor of the craniocervical junction and destructive spondyloarthropathy (DSA) are the most serious forms of dialysis amyloidosis (DAA). Pain and paralysis due to these lesions significantly impair activity of a patients' daily life (ADL). CAPD improved ADL of a 54 year-old male patient complicated with various forms of DAA after 17 years of hemodialysis (HD) treatment. He was first diagnosed as having carpal tunnel syndrome 12 years after initiation of hemodialysis followed by dialysis shoulders(12 years), trigger fingers(12 years), bone cysts(15 years), tendon ruptures(17 years), DSA and a pseudotumor of the craniocervical junction(17 years). Magnetic resonance imaging (MRI) taken in May 1989 revealed a pseudotumor of the craniocervical junction, which was 30 mm in diameter, located in front of partially destroyed C1 and C2. Neck pain and muscle weakness rendered him bed ridden. Six months after switching to CAPD with administration of prednisolone, neck pain disappeared. He recovered the muscle power by physical rehabilitation. At last it became possible for him to perform the CAPD procedure by himself and drive a car to the hospital as an out patient. In such cases of pseudotumors of the craniocervical junction, CAPD is one of the best methods for relieving the pain and muscle weakness.

Activities of Daily Living↗
PubMed1992

Serological and virological studies of Japanese encephalitis in the Terai region of Nepal.

In 1987 and 1990, serum samples were collected from people living in the two districts (Itahari and Chitwan) of the Terai region of Nepal. Antibodies against Japanese encephalitis (JE) virus in these sera were detected by the hemagglutination inhibition (HI) and neutralization (N) tests. By the HI test, 26 out of 172 (15.1%) sera from Chitwan and 15 out of 137 (10.9%) sera from Itahari showed positive titers. Higher positive rates were shown by the N test, where 46 out of 172 (26.7%) sera from Chitwan and 22 out of 137 (16.1%) sera from Itahari had antibodies against JE virus. A JE strain was isolated from a blood specimen of a pig raised in Kathmandu. When the nucleotide sequence of the pre-M region of the strain was compared to the same region of the other JE virus strains reported, the highest similarity was observed to the strains isolated in Nepal in 1985. These results suggest that the Terai region has been an epidemic area of JE.

Adolescent↗
PubMed1992

[A case report; 5'-DFUR reduced gastric cancer with multiple liver metastasis].

We describe a case of gastric cancer with multiple liver metastasis that clearly decreased in size after administration of 5'-DFUR. The patient (a 63-year-old male) was inoperable because of multiple liver metastasis. 5'-DFUR 600 mg/day reduced the size of the multiple liver tumors (reduction rate 90%, partial response for four months), but the gastric tumor was unaltered. A rapid decrease in alkali-phosphatase indicated reduction of the liver tumors only one week after the initiation of 5'-DFUR.

Adenocarcinoma↗
PubMed1992

[A case of prolactinoma presenting with CSF rhinorrhea and CSF otorrhea during bromocriptine therapy].

Cerebrospinal fluid (CSF) leakage is a rare complication of prolactinoma treated with bromocriptine (BC). BC is known to be effective for reducing the volume of a prolactinoma and for decreasing the serum level of prolactin (PRL). In cases of pituitary tumors, CSF leakage is thought to be caused by shunting between the subarachnoid and extradural spaces. We had a case presenting with CSF rhinorrhea and CSF otorrhea during BC therapy which was treated successfully. The mechanism and treatment of CSF leakage were studied. A 55-year-old woman complaining of nasal obstruction and headache was admitted to our hospital on Nov. 22, 1988. CT scan showed a huge intracranial mass lesion involving the sella and the supra-sellar region and invading the sphenoid sinus and ethmoid sinus. Serum PRL level was 18,000 ng/ml. The patient was diagnosed as having an invasive prolactinoma, and BC therapy (5.0 mg per day) was instituted. Three days later, CSF rhinorrhea developed, and BC treatment discontinued; radiation therapy was started. After 36 Gy irradiation the size of the tumor was same on CT, and serum level of PRL was still high. The patient underwent trans-sphenoidal operation. The tumor was removed partially and the presumed CSF fistula was repaired. The sella and sphenoid sinus were packed with fat. BC treatment was reinstituted, and the serum PRL level decreased gradually without recurrent CSF rhinorrhea. Two weeks later the patient returned complaining of bilateral hearing disturbance. With a diagnosis of exudative otitis media she underwent bilateral tympanostomy. Immediately after tympanostomy, pulsating discharge from the middle ear was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromocriptine↗
PubMed1992

[Effects of Nd:YAG laser irradiation on ventricular myocardium in dogs using an artificial sapphire tip contact laser catheter].

To apply Nd:YAG laser irradiation through a new sapphire tip contact laser method to catheter ablation in treatment of tachy-arrhythmias, effects of laser irradiation on ventricular myocardium were investigated in 10 mongrel dogs. Nd:YAG lase (1064nm) discharges were delivered to different sites on the endomyocardium at power of 5, 10, 15, 20 or 25w with duration of 3, 5, or 10 seconds (sec.) respectively in closed beating hearts. Histopathologically, the lesion irradiated was clearly demarcated from the normal myocardium by the construction band necrosis zone. The depth of injured myocardium was less than 2mm with 3 sec. irradiations, with 5 sec. from 1 mm to 4 mm in proportion to power increase, with 10 sec. from 3mm to 8 mm in proportion to the power from 5w to 15w and could not be measured in cases of more than 20w irradiations. Although with every irradiation duration, the depth of injury increased in proportion to the power increase. With the same total energy, a longer time of irradiation produced deeper injury than a shorter time. This method makes it easier to keep the laser positioned to target than bare laser, and is suitable for use in catheter ablation.

Animals↗
PubMed1992

Practical applications in molecular biology of sensitive fluorescence detection by a laser-excited fluorescence image analyzer.

A new kind of fluorescence image analyzer was developed for a variety of uses, especially in molecular biology. Compounds labeled with fluorescent groups on a gel or nitrocellulose membrane are excited with 532 nm of light from a green laser. The fluorescence emitted passes through light-collecting fibers to a photomultiplier. Imaging data converted from the emitted light are analyzed by a microcomputer and stored on a magnetic optical disk. Dideoxy DNA sequencing was done with the same amount of DNA used for autoradiography, and the sequencing ladders obtained from gel scanning were automatically converted to sequence data by the analyzer. When an agarose gel was analyzed after electrophoresis, DNA stained with ethidium bromide was detected by the analyzer with higher sensitivity rather than by the conventional photographic method. Nylon and nitrocellulose membranes could be read by the analyzer, so blot hybridization experiments can be done without radioisotopes. High-quality computer storage of the imaging data from gel electrophoresis and hybridized membranes, including pulsed-field gels, make it possible to quantify image intensity and to construct many kinds of databases.

Base Sequence↗