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Biomedical subjects

T Tamiya

Publications and source records attributed to T Tamiya.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Surgical landmarks of course of atrioventricular conduction system].

There is a certain tendency in the relationship between the distribution of the conduction system and the type of VSD as classified by Soto and coworkers. The course of the conduction system and its surgical landmarks were investigated histologically in various cardiac anomalies. In perimembranous inlet VSD, the His bundle ran superficially on the crest of the ventricular septum. It ran on the left ventricular aspect and somewhat deeply in trabecular VSD and far deeply in infundibular VSD. In perimembranous inlet or trabecular VSD, the RBB laid beneath or just anterior to a series of upper-uppermost accessory papillary muscle when these were present and descended posteroinferior to the MPM, basically as in the normal heart. The upper-uppermost AcPM are reliable landmarks for the RBB. The RBB descended just anterior to the so called MPM (embryologically the uppermost AcPM--Van Mierop) in infundibular VSD and TOF. These findings have provided us useful bases for suture placement to avoid conduction disturbance.

Bundle of His↗
PubMed1988

Complement activation in cardiopulmonary bypass, with special reference to anaphylatoxin production in membrane and bubble oxygenators.

Complement activation by cardiopulmonary bypass (CPB) was studied in 82 patients divided into membrane (MOG) and bubble oxygenator groups (BOG). The influence of primed homologous to circulating autologous blood volume (H/A) ratio was also evaluated. C4a increased very slowly during CPB in both groups, maintaining slightly higher levels in the BOG than in the MOG, with the exception of a marked initial rise in the BOG with a high H/A ratio (greater than or equal to 20%). Anaphylatoxin C3a levels increased more steeply in the BOG than in the MOG. An obvious rise in anaphylatoxin C5a production was observed in the BOG alone. The influence of high H/A ratio perfusion on complement activation was milder in the MOG than in the BOG. In 20 monkeys (Macaca fascicularis), continuous intraaortic infusion with bubbled autologous blood increased C4a and C3a levels, while autologous blood extracorporeally contacted with nylon increased C3a levels alone. In vitro studies revealed that human immunoglobulin fractions denatured by oxygen bubbling produced C4a, C3a, and C5a in a dose-dependent manner, although human albumin treated identically as human immunoglobulin did not produce these complements. It was thus inferred that (1) during CPB, complement is predominantly activated via the classical pathway in the BOG and via the alternative pathway in the MOG; (2) higher anaphylatoxin levels in the BOG than in the MOG are related to mode and grade of blood trauma; (3) anaphylatoxin level differences in both groups tend to increase with high H/A perfusion; and (4) immunoglobulin-free sera may reduced classical pathway activation.

Animals↗
PubMed1988

Movement of water in conjunction with plant movement visualized by NMR imaging.

The water distribution in the pulvinus of Mimosa can be visualized by an NMR imaging technique. After stimulation of a Mimosa plant, water in the lower half of the main pulvinus disappeared, the water previously contained in this area seeming to be transferred to the upper half of the main pulvinus. Movement of the water in conjunction with Mimosa movement was visualized sequentially by a non-invasive NMR imaging procedure.

Magnetic Resonance Spectroscopy↗
PubMed1988

Hyperthermia for brain tumors: improved delivery with a new cooling system.

Hyperthermia has emerged as an adjunct to other forms of brain tumor therapy. Interstitial microwave irradiation is an effective method of inducing localized brain hyperthermia. One of the problems with this technique, however, is the overheating of tissue adjacent to the antenna. In this study, a cooling system for the interstitial microwave antenna was developed for the purpose of providing uniform and accurate heating by the elimination of overheating. The ability to generate more uniform hyperthermic fields was evaluated in normal monkey brains. Six monkeys under general anesthesia and controlled respiration underwent parietooccipital craniectomies 4 x 4 cm in size. The antenna cooling system was constructed of a silicone tube 5.0 mm in outer diameter. Silicone-coated interstitial microwave antennae 1.5 mm in diameter were used. A single antenna or a square array (1.6 cm on a side) of 4 antennae was inserted into the brain with the coupled system to a depth of 2 cm. The brain tissue was heated by 2450-MHz microwave irradiation. Temperature distributions were mapped using nonperturbing thermocouples. These thermal profiles were compared with those generated without the cooling system. In the experiments with the single antenna, the antenna cooling system eliminated the overheating and rapid radial falloff in temperature, without a reduction of the hyperthermic field. In the four-antennae experiments using the cooling system, the thermal field was dramatically flattened with minimal reduction in size; however, the area maintained at a therapeutic temperature range (42-45 degrees C) was significantly enlarged by the cooling system.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[A case-control study of testicular cancer].

A study on the possible association of maternal factors with testicular cancer was undertaken. Information was obtained from the mothers of testicular cancer cases (N = 37) and the mothers of men without the disease (N = 37). Comparisons were made between the two groups. The cases were collected from the records of nine hospitals, and the controls were selected from five Public Health Centers by individually matching the sex and the year of birth with the testicular cancer cases. The mothers of the cases had significantly fewer live births than the mothers of the controls (the adjusted odds ratio per live birth = 0.4, p = 0.02), when the five following variables had been simultaneously adjusted by the logistic regression analysis. Those five variables included the Quetelet's Index of mothers before pregnancy, the age at an index birth, the duration of breastfeeding for an index child, the birth order of an index child, and the number of induced abortions. The endogenous hormonal milieu of a mother may be associated with the occurrence of testicular cancer in her child.

Abortion, Induced↗
PubMed1987

[Clinical efficacy of oxendolene (antiandrogen) and bunazosin hydrochloride (alpha-adrenergic blocker) in the treatment of prostatism--comparative study of oxendolone, bunazocin hydrochloride and their combination].

Antiandrogen and alpha-adrenergic blockers have recently been tried in the medical treatment for benign prostatic hypertrophy and bladder neck contracture. We herein report our results of a randomized comparative study on the clinical efficacy of oxendolone, bunazosin hydrochloride (bunazosin) and their combination for the treatment of benign prostatic hypertrophy and bladder neck contracture. The attending doctors evaluated at twelve weeks the improvement rate for three treatment regimens, 400 mg/day oxendolone, 3 mg/day bunazosin and a combination of both. Oxendolone + bunazosin showed the highest improvement rate in the evaluation of each subjective symptom and objective finding and of both. Oxendolone + bunazosin tended to show a better clinical efficacy than the other of these regimens, when the improvement was defined as that with more than one degree in the severity of retarded voiding, prolonged voiding, urinary stream condition, abdominal pressure on voiding and residual urine sensation. The improvement of such subjective symptoms seemed to occur earlier with oxendolone + bunazosin or bunazosin than with oxendolone. A significant difference was shown among the three treatment regimens in the general improvement rate on four subjective symptoms, with oxendolone + bunazosin being the highest followed by bunazosin and oxendolone in this order. The improvement rates of maximum and mean flow rate which are most important parameters to evaluate the voiding condition, at twelve weeks were significantly higher with oxendolone + bunazosin. No serious side effects were observed in this study, although treatment regimens containing bunazosin caused some minor side effects. These side effects could be prevented by the use of initial low doses of bunazosin with a subsequent gradual increment up to 3 mg/day. Taking the differences in the mechanism of oxendolone and bunazosin and the results of our study into consideration, we believe that the combination of oxendolone and bunazosin would be more useful in a clinical situation.

Adrenergic alpha-Antagonists↗
PubMed1987

[Fundamental study of differential hypothermia treatment of brain tumor using an interstitial microwave antenna].

An interstitial microwave antenna system was devised for differential hypothermia treatment. It was evaluated for its ability to induce localized brain hyperthermia in hypothermic monkey. Ten brain hyperthermia trials have been performed in 6 monkeys. Under general anesthesia, the animals were put into ice water bath to keep the total body temperature at 30 degrees C. Following parieto-occipital craniectomy, a microwave antenna of 1.5 mm in diameter was inserted into the brain at depth of 2 cm, and the brain tissue was heated by 2450 MHz microwave irradiation. Thermal distribution was measured by thermistor probes and local cerebral blood flow (1-CBF) before and after heating was simultaneously measured by hydrogen clearance method. After the experiment, the animals were sacrificed and histopathological changes of the heated brain tissue were studied. Under total body hypothermia of 30 degrees C, the maximum cross-sectional diameter of the heated brain to 37 degrees C or above was about 4 cm. The temperature profile on the vertical plane presented a bell-shaped distribution. The 1-CBF of the heated brain increased with the elevation of the brain temperature and the blood flow at 37 degrees C is nearly twice as much as that of 30 degrees C. After one hour DH treatment, necrotic tissue was noted along the antenna axis where the temperature was maintained more than 50 degrees C, and this change was not recognized at a distance of 1 cm from the antenna where the temperature was maintained at 42 degrees C. This study indicates that interstitial microwave hyperthermia system can be used effectively to heat the localized brain tissue.

Animals↗
PubMed1985

Freeze denaturation of enzymes and its prevention with additives.

Freeze inactivation of LDH, MDH, ADH, G-6-PDH, and PK and its prevention with additives such as sodium glutamate and albumin were studied. LDH, MDH, ADH, G-6-PDH, and PK, each lost their activity during frozen storage at -20 degrees C. The speed of the inactivation differed in each. The stability of the enzymes increased with the increase of the enzyme concentration. Sodium glutamate and albumin prevented the freeze inactivation. While the activity of the LDH solution frozen without additives was almost lost during a day of frozen storage, those frozen with either glutamate (0.2 M) or albumin (0.1%) added decreased less quickly. The residual activity after 1 day was 50% the initial prefreeze value for the former and 10% for the latter, respectively. Combined use of glutamate and albumin prevented the inactivation the best and maintained the initial activity almost completely over 6 weeks. The enzymes tested lost some part of their activity when their solutions were diluted by the media. This inactivation was prevented to a significant extent by the addition of sodium glutamate and/or albumin to the diluting media.

Alcohol Dehydrogenase↗
PubMed1985

Purification and characterization of an antibacterial factor from snail mucus.

The antibacterial factor from the body surface of the African giant snail, Achatina fulica Férussac, was isolated by DEAE-Toyopearl 650M ion exchange chromatography. The isolated preparation exhibited highly positive antibacterial activity both for the Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus and for the Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, but it lost such activity when heated at 75 degrees C for 5 min. The antibacterial factor of the snail mucus was a glycoprotein whose molecular weight (MW) was about 160,000. It was composed of two subunits of MW 70,000-80,000.

Animals↗