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Biomedical subjects

K Yagyu

Publications and source records attributed to K Yagyu.

At least 91 records · Page 5Linked to original sources

Floating cells in anterior chamber after IOL implantation.

Following planned extracapsular cataract extraction (PECCE) and posterior chamber lens implantation in rabbit eyes, aqueous humor samples were aspirated on the 3rd and 7th postoperative days and examined by transmission electron microscopy. The controls were cells from the aqueous humor of eyes which underwent only PECCE. Six different types of cells, namely, erythrocytes (including ghost erythrocytes), polymorphonuclear leukocytes, macrophages, lymphocytes, eosinocytes and plasmacytes, were observed in the aqueous samples, the following results were obtained. 1) In one control eye there was no significant difference in the ratio of macrophages between the 3rd and the 7th postoperative days. 2) On the 3rd postoperative day there was a significant increase in the macrophage ratio between one IOL implanted eye and one control eye (P less than 0.1). 3) On the 7th postoperative day there was a marked increase in one IOL implanted eye in the frequency of macrophages compared to the 3rd postoperative day of the same eye and the 7th postoperative day of one control eye. It was concluded that the macrophages had a close relationship with a specific cellular response to IOL implantation.

Animals↗

[Mitral valve disease with pulmonary hypertension: two surgical cases].

Two surgical cases of mitral valve disease with severe pulmonary hypertension were reported, in which pulmonary hypertensive crisis (PHC) was a really serious problem to be treated. The first case (60-year-old woman) had atrial fibrillation and her pulmonary artery pressure was 68/32 mmHg (Pp/Ps = 0.63) and mean pulmonary wedge pressure was 26 mmHg with a high v wave (46 mmHg). PHC developed immediately after the cessation of artificial cardiopulmonary bypass, and intraaortic balloon pumping was performed. However, it was difficult to wean from the assist circulation, and then PGE1 and isoproterenol were given into the pulmonary artery and epinephrine and norepinephrine were given into the left atrium, and we succeeded in weaning from the assist circulation. The second case (58-year-old woman) had high pulmonary artery pressure (86/37 mmHg) and the Pp/Ps was 0.73. According to the experience of the first case, prevention of PHC started during cardiopulmonary bypass, giving PGE1, nitroglycerin and torazoline into the pulmonary artery. This led to the easy weaning from cardiopulmonary bypass. PHC may be seen even in cases of acquired valvular disease, and the prevention is mandatory for uneventful surgery.

Cardiopulmonary Bypass↗

[Surgical approach and long-term results on replacement of the aortic valve and ascending aorta with a composite graft].

From March, 1980 to January, 1991, 18 patients, 14 male and 4 female patients ranging in age from 22 to 63 years, were operated on for aortic regurgitation associated with an aneurysm of the ascending aorta. Twelve patients had annuloaortic ectasia; six had DeBakey type I or II dissection; three had Marfan syndrome; and one had aortitis syndrome. The surgical treatment consisted of 16 Bentall operations and 2 modified Cabrol operations with a composite graft and aortic wrapping. The operative mortality was 5.6% (one death). The late mortality has been 4/15. The actuarial survival rate is 82.6% at 5 years and 72.3% at 7 years. Modified Cabrol technique consists of two short interposed grafts with equine pericardial miniskirts between coronary ostia and composite graft, in which Carbomedics mitral valve (No. 23 or 25) is placed 5-10 mm above the proximal extremity. This technique is a safe and reliable method with no bleeding nor mortality and excellent long-term results.

Adult↗

[Results and problems of cardiac surgery in the elderly (70 years of age or older)].

Fifty-nine cardiac patients with 70 years of age or older were operated in our Department from 1979 to 1990. The mean age was 73.1 years old, and the male/female ratio was 27/32. The operative procedures performed were CABG in 35 cases, the closure of VSP in 4 cases, the valve surgery in 17 cases and the others in 3 cases. In CABG cases, the operative and late mortalities of the elderly patients were both 2.9% (1 case each), which were comparable to those of the younger patients. The restriction of the bypass grafting only to the key coronary arteries to reduce the operative time was considered to be important. In VSP cases, three of four patients were operated in the acute phase, one being lost because of in-hospital contamination. In the valve group, 24% (4 cases) were lost in the early postoperative period, which was much higher than that of the younger patients (7.2%). The earlier decision of the operation and the use of smaller prosthetic valve avoiding time-consuming aortic root enlargement were considered to be important to reduce the mortality. It is concluded that the results of cardiac surgery in the elderly patients could be satisfactory if one considers its peculiarity well.

Age Factors↗

Impaired responsiveness of paraventricular neurosecretory neurons to osmotic stimulation in rats after local anesthesia of the subfornical organ.

Extracellular recordings were obtained from 32 phasically active neurosecretory cells in the hypothalamic paraventricular nucleus (PVN) of urethane-anesthetized male rats. None of the PVN cells changed their activity to intracarotid infusions of isotonic saline (0.15 M NaCl solution, 0.05 ml). Of these PVN neurons, 26 displayed an increase in neuronal activity following intracarotid infusions of hypertonic saline (0.2 M NaCl solution, 0.05 ml), while the remainder were unresponsive. Microinjection of the local anesthetic lidocaine into the subfornical organ (SFO) reversibly diminished the excitatory response to the infusions of hypertonic saline in 10 out of 15 PVN neurons tested, whereas the injection of lidocaine into the vicinity of the SFO (n = 4) or the third ventricle (n = 4) did not cause a marked change. These results show an involvement of the SFO in the mechanism of osmotic activation of putative vasopressin (AVP)-secreting neurons in the PVN.

Action Potentials↗

Purification of infectious bronchitis coronavirus by Sephacryl S-1000 gel chromatography.

A procedure was developed to purify infectious bronchitis virus (IBV) by gel chromatography (GC) with a Sephacryl S-1000 column. Virus samples concentrated by centrifugation were applied to a Sephacryl S-1000 column and eluted by 0.02 M phosphate buffer (pH 7.2) containing 0.15 M NaCl. Virus particles were recovered mainly in the first peak. Purity of the samples was evaluated by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electron microscopy. Using electron microscopy, it was found that there were more spike-rich particles in the virus samples purified by GC than in those purified by sucrose density gradient centrifugation (SDGC). In addition, the hemagglutination unit [log10 (infectivity titer/hemagglutination titer)] of GC-purified virus samples was approximately 10 times lower than that of SDGC-purified virus samples. These results indicate that Sephacryl S-1000 gel chromatography is useful for purification of IBV.

Animals↗

[A study on fatty liver in health examination participants].

We investigated the condition of the liver in a total of 5486 subjects (3889 males and 1597 females) who received adult-disease screening examinations. The following results were obtained. 1. Fatty liver was found in 13.9% of the males and 3.8% of the females with a male/female ratio of about 3.7 to 1. In males, the prevalence of fatty liver was lower in those in their 20's than in any other age ranks, while there was little difference in the age range from the 30's to the 50's. In females, the prevalence sharply increased in those in their 50's. 2. The percentage of fatty liver increased with the obesity index in both males and females. 3. With respect to alcohol drinking, the prevalence of fatty liver was not affected by the presence or absence of alcohol drinking, the daily drinking quantity and total drinking quantity. 4. Of those screened for adult disease, 14.7% of the males and 2.7% of the females had abnormal liver function, with a male/female ratio of about 5.4 to 1. In both males and females, the prevalence of fatty liver was higher in those who had abnormal rather than normal liver function.

Adult↗

Importance of the mitral complex in left ventricular contraction--an analysis of the results of mitral valve replacement with preservation of the posterior mitral complex.

The importance of the mitral complex in left ventricular contraction was studied in seventy-five patients who underwent mitral valve replacement (MVR) with preservation of the posterior mitral complex (modified MVR:mMVR), and in one hundred and twenty-two patients who had conventional mitral valve replacement (cMVR). Mechanical heart valves (Medtronic Hall or St. Jude Medical valves) were used in MVR. Patients after mMVR showed lower left atrial pressures, higher left ventricular stroke work indexes, and better left ventricular function curve using less catecholamines than those after cMVR during the initial 24 hours following cardiopulmonary bypass. M-mode echocardiographic analysis revealed that the sequential apex-to-base contraction of the ventricular wall was better preserved after mMVR than after cMVR. This tendency was more prominent in mitral regurgitation (MR) than in mitral stenosis (MS) patients. Echocardiographic analysis revealed that the posterior mid left ventricular segment began to contract and reached maximal contraction earlier than the basal segment in patients before and after mMVR. After cMVR, this tendency was less noticeable, and the contraction processed and peaked almost simultaneously in all segments. The mitral complex plays an important role in left ventricular contraction, and modified MVR can be said to be an excellent procedure for preserving left ventricular function.

Cardiopulmonary Bypass↗