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Biomedical subjects

T Yamashiro

Publications and source records attributed to T Yamashiro.

At least 109 records · Page 6Linked to original sources
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

[Renal toxicity by intraperitoneal administration of CDDP].

Renal toxicity following intraperitoneal (ip) CDDP therapy after laparotomy in twenty patients with ovarian cancer was examined. Four patients had renal toxicity. Patients who received CDDP at a dose of 150 mg (2/2) had a statistically higher incidence of toxicity than those who received less than 100 mg (2/18) (p less than 0.05). Patients who underwent ip therapy on the same day as laparotomy had a statistically higher incidence of the toxicity (4/15) than those underwent it on the fourth day after (0/5) (p less than 0.05). Renal toxicity was revealed in the mean urine volume of 1,100 ml on the day of therapy, but the toxicity did not appeared in those with a mean urine volume of 2,131 ml, whose volume was statistically different (p less than 0.01). These data suggest maintenance of renal blood flow during CDDP treatment plays an important role in preventing renal toxicity even following ip therapy. By investigating preoperative laboratory data, it is seen that patients with FDP values higher than 32 micrograms/ml have a higher risk of renal toxicity.

Adult↗
PubMed1985

A histological study of surgical landmarks for the specialized atrioventricular conduction system, with particular reference to the papillary muscle.

Surgical landmarks of the conduction system were histologically evaluated in 29 cardiac specimens. The distribution of the system was grossly inherent to the type of ventricular septal defect as classified by Soto and coworkers, although it varied individually. The relationship of the right bundle branch (RBB) to the papillary muscles was of surgical interest. In defects unrelated to maldevelopment of the septum of the conus, the RBB passed beneath or slightly anterior to upper accessory papillary muscles (AcPMs) and posterior to the medial papillary muscle (MPM), regardless of the subtype of defect. In defects caused by maldevelopment, such as tetralogy of Fallot, it passed anterior to the MPM. Such data support the hypothesis that the RBB descends beneath or anterior to embryological upper AcPMs, whatever the morphological role may be, because of the supposedly independent developmental origin of the MPM and AcPMs. The relationship between the RBB and upper AcPMs appeared further modified by the attitude of the trabecula septomarginalis. Our improved clinical results have demonstrated that such information offers a gross but practical guide for prevention of conduction disturbances.

Aged↗
PubMed1985

[A histologic study on "surgical landmarks" of the specialized conduction system, with particular reference to the adjacent structure].

The conduction system in 29 cardiac specimens was histologically investigated as to the course and its surgical landmarks. The course varied individually, but was relatively inherent to the type of ventricular septal defect (VSD) (classification by Soto, et al.). The His bundle distributed as reported hitherto. Interesting features were noted in the relationship between the right bundle branch (RBB) and its adjacent papillary muscles. Our definition used for certain papillary muscles is merely to point the topographic site. The RBB ran beneath or slightly anterior to upper accessory papillary muscles (AcPMs) or uppermost AcPM, regardless of the type of perimembranous VSD. It ran posterior to the medial papillary muscle (MPM), with wider variation. In tetralogy of Fallot (TOF), it ran beneath or slightly anterior to the MPM. Relationships described above may be unitarily expressed as below, providing that Van Mierop's embryologic hypothesis on the conus defect anomaly (i.e.,: the uppermost AcPM being often morphologically interpreted as the MPM) is valid: -"The RBB runs beneath or slightly anterior to the upper(most) AcPM, regardless of the type of VSD. Such an arrangement was often observed in other anomalies too. The relationship between the RBB and upper or uppermost AcPM was modified by the attitude of the trabecula septomarginalis. Informations thus obtained have significantly lowered conduction disturbances in our experience.

Aged↗
PubMed1982

Clinical appraisal of his bundle electrocardiogram taken under cardiotomy in congenital heart disease.

The specialized conduction system in the heart was electrophysiologically delineated under cardiotomy in 74 patients with congenital heart disease primarily to determine the topographic relationship of the conduction system to intracardiac structures. Histological study was also done to evaluate the electrophysiological data. Differences were found between the ordinary ventricular septal defect (VSD), inlet-type perimembranous defect, and the ordinary tetralogy of Fallot (TOF), outlet-type perimembranous defect. A superficial run of the His bundle along the lower rim summit of defect was often demonstrated electrophysiologically in large VSD of types II or III, whereas the bundle took marked leftward course in TOF. The right bundle branch (RBB) ran beneath or slightly posterior to the Lancisi equivalent structure (LES) in VSD, while it ran under or slightly anterior to LES in TOF. This papillary muscle could be a rough landmark of the RBB. The course of the RBB in TOF, however, had to be histologically confirmed, since its deep location made electrophysiological delineation difficult. All the sites with a high deflection were the areas where the conduction system was histologically demonstrated beneath the endocardium.

Adolescent↗
PubMed1982

The TM bubble oxygenator: development and clinical application.

A bubble oxygenator (the TM or the OCVC oxygenator) has been produced with development efforts focused particularly on reduction of the nonphysiological characteristics of this type of oxygenator. The structural features of the apparatus are: (1) a reduction to the minimum of adequate priming volume, (2) an oxygen disperser designed to ensure evenly dispersed, uniform-sized bubbles, (3) a volume-control system for the oxygenating chamber (the OCVC system) based on extensive experimental oxygenation studies, and (4) an integrated double microfilter of the gravity-drainage type. Clinical features are: (1) ease of operation in perfusion, (2) reduction in hemolysis and postoperative blood loss, and (3) fewer complications associated with microemboli. Clinical use on over 200 infants and children proved generally very satisfactory. The background of its development is briefly described as are future modification plans.

Cardiac Surgical Procedures↗
PubMed1982

Electrophysiological delineation of the specialized conduction system under cardiotomy and its clinical role.

Electrophysiological delineation of the specialized conduction system was performed under cardiotomy on 64 patients: 51 with ventricular septal defect (VSD), 11 with tetralogy of Fallot (TOF) and 2 with transposition of the great arteries (TGA, III). Some histological study was done for confirmation. In large VSD of type II or III, superficial location of the His bundle was shown by a tall H deflection recorded along the inferior rim, coinciding with a high incidence of conduction disturbance in this malformation. One characteristic in TOF was a deflection recorded along the posteroinferior rim rather exclusively on the left ventricular side, coinciding with the anatomic course of the His bundle. A deflection was frequently recorded at an area a few mm posterior to the muscle of Lancisi (ML) or the Lancisi equivalent structure (LES); it was relatively common in ordinary types of VSD, and presumed as the penetrating site of the right bundle branch (RBB) and/or near the bifurcated portion of the His bundle. The second portion of the RBB was not clearly delineated in general, particularly in TOF, but always found within the septomarginal trabecle when delineated. Our conclusion, together with histological study, was that one may use the ML or the LES as a rough marking for the course of the RBB. By this recognition, the surgically induced complete right bundle branch block has been diminished significantly. Variation of the course of conduction system as well as limits of this diagnostic measure are described herein.

Adolescent↗