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Biomedical subjects

M Ohtani

Publications and source records attributed to M Ohtani.

At least 199 records · Page 11Linked to original sources
PubMed1989

[Intraoperative echocardiographic assessment of left ventricular muscle volume changes after intracardiac operation under cardiopulmonary bypass].

Cardiopulmonary bypass (CPB) and concomitant cardioplegic arrest (CA) may cause impairment of cardiac function with development of myocardial edema. There are few reports of intraoperative assessment of LV mass or muscle volume (MV) in patients, Fifteen patients (age; 0.5-68), 10 with congenital and 5 with valvular diseases, were studied by epicardial 2-dimensional and M-mode echocardiography. LVMV was obtained from M-mode study at pre- and post-CPB during surgery. Pre and post CPB LVMV-index (ml/m2) and percent change of LVMV were compared. CPB-time was 170 +/- 78 min (mean +/- SD), and CA time was 97 +/- 49 min. LVMV index increased significantly from 89 +/- 35 to 103 +/- 43 ml/m2 after CPB (p less than 0.01). Percent change ranging from -3 to +37% (14 +/- 12) correlated to CPB time (r = .81, p less than .01) and also to CA time (r = .62, p less than .05). These results indicated that CPB with CA caused acute increase in LVMV with a positive relation to its duration.

Adolescent↗
PubMed1989

[Urogenital cancer].

Treatment of urogenital cancer has made great progress due to early detection by various imaging techniques. Renal cancer is a good example of cancer that has been diagnosed in the earlier stages by the routine imaging methods. BRM therapy of interferons and interleukin II has been proved useful for renal cancer. It has been difficult to diagnose the wall invasion of the bladder cancer. However, ultrasonic imaging has made it possible to detect precisely the invasion into the vesical muscles and adventitia. Also, prostatic acid phosphatase and prostatic specific antigen have become more specific markers for prostatic cancer. Various treatments for this malignancy, including operative surgery, have made progress. The results of chemotherapy for testicular cancer have become fruitful by the use of cisplatin.

Humans↗
PubMed1989

Surgery for aortic arch aneurysm with selective cerebral perfusion and hypothermic cardiopulmonary bypass.

Deep-hypothermic cardiopulmonary bypass with selective cerebral perfusion (SCP) was used in 34 consecutive patients with aneurysms involving the aortic arch or the adjacent part of the aorta. The ages ranged from 25 to 79 years (mean, 56 years). Atherosclerotic aneurysms were present in 14 patients, dissecting aortic aneurysms in 16, and other lesion types in four. Replacement of the ascending aorta was performed in 10 patients, replacement of the ascending aorta and arch in 12, replacement of the distal arch in two, and other procedures in 10. Perfusion techniques consisted of femoral artery perfusion and SCP to the brachiocephalic trunk and the left common carotid artery. The blood temperature was maintained at 16 degrees-20 degrees C. SCP time ranged from 25 to 214 minutes (mean, 123 minutes). Operative death occurred in three (9%) patients. Neurological sequelae occurred in one patient (cerebral infarction), but significant respiratory and hemorrhagic problems were not encountered. For the SCP protocols, we advise that perfusion pressures at bilateral superficial temporal arteries be kept at approximately 50 mm Hg and that venous oxygen saturation of the superior vena caval line or internal jugular vein be kept at above 90%. With appropriate monitoring, this method can be performed in aortic arch or related surgeries with low morbidity results.

Adult↗
PubMed1989

[The long-term prognosis of intra-arterial chemotherapy in invasive bladder cancer].

During the period from August 1980 to April 1989, preoperative intra-arterial infusion chemotherapy was performed in 22 patients with resectable bladder cancer. An oblique incision approximately 12 cm long was made in the gluteal lesion to expose the inferior gluteal artery, into which a Teflon catheter was inserted and fixed. Via this catheter, a single dose of 10-20 mg CDDP and/or 10 mg ADM was injected 1-2/week. The majority of patients were treated with radiation and/or hyperthermia as a combined therapy. The 5-year survival rates (Kaplan-Meier method) were 81.6% in patients treated with intra-arterial infusion chemotherapy as an adjuvant to total cystectomy, compared with 37.5% in patients treated with total cystectomy only. There was a statistically significant difference between the two groups (p less than 0.01). Therefore, inferior-gluteal-artery infusion chemotherapy is effective as a preoperative adjuvant therapy with no serious side effects.

Aged↗
PubMed1989

[Experimental and clinical assessment of myocardial protective effect of a prostacyclin analogue (OP 41483)].

The beneficial effects of a stable prostacyclin analogue (PGI2-A), OP 41483 against myocardial ischemic injury were experimentally and clinically evaluated. In 31P-NMR study, the preischemic treatment with PGI2-A prevented myocardial ATP depletion of rat hearts which were subjected to 20 min global ischemia. In patients with congenital heart disease, the PGI2-A of 300 ng/ml was added to the glucose-insulin-potassium cardioplegia (PGI2-group), and this group was compared to control group without PGI2-A in terms of postoperative maximal leakage of CPK-MB (maxCPK-MB). In patients under 1 yr or patients over 1 yr with aortic cross clamp time exceeded 120 min, the maxCPK-MB was significantly (p < 0.05) reduced as compared to the control. This stable PGI2 analogue has shown significant myocardial protective effects experimentally and also in clinical setting.

Animals↗
PubMed1988

Cyanide distribution in five fatal cyanide poisonings and the effect of storage conditions on cyanide concentration in tissue.

The cyanide distribution in five fatal cyanide poisonings was analyzed by the pyridine-pyrazolone method using a Conway diffusion cell. In order to study the effect of storage conditions on cyanide concentration in tissue samples, the cyanide concentrations were first measured immediately after collection of the samples at autopsy, then measured again after storage in a refrigerator (4 degrees C) or in a freezer (-20 degrees C) for periods ranging from 1 day to 3 weeks. Concentrations in all but three of the blood samples stored at 4 degrees C or -20 degrees C increased, with concentration ratios based on measurement made before and after storage ranging from 0.71 to 1.46. The concentrations in the liver, kidney, and brain samples either increased or decreased, with ratios of from 0.2 to 8.8. The concentrations in the stomach contents samples decreased rapidly at 4 degrees C, but hardly changed at all at -20 degrees C.

Adult↗
PubMed1988

Sequential changes in the prostate of rats treated with chlormadinone acetate, testosterone and N-nitroso-N-methylurea.

An attempt was made to induce prostatic adenocarcinoma in rats. Temporary chemical castration of F344 rats was achieved by administration of diet containing 0.05% chlormadinone acetate (CMA) for three weeks. The prostate was then stimulated by three consecutive daily intramuscular injections of testosterone propionate (100 mg./kg.). On the day after the last testosterone injection, N-nitroso-N-methylurea (NMU) (50 mg./kg.) was injected intravenously. Animals were sacrificed 10 days and 4, 20, 40 and 60 weeks after NMU treatment. Well-differentiated adenocarcinomas were obtained in three of fifty-four animals (5.6%) by this treatment and a high incidence of simple hyperplasia (88%) and atypical hyperplasia (19%) was also observed at 60 weeks. More studies are necessary to develop a protocol resulting in more rapid induction of prostatic adenocarcinomas at higher incidence.

Adenocarcinoma↗
PubMed1988

Synthesis and in vitro activity of various derivatives of a novel thromboxane receptor antagonist, (+/-)-(5Z)-7-[3-endo-[(phenylsulfonyl)amino]bicyclo[2.2.1] hept-2-exo-yl]heptenoic acid.

Several sulfonyl derivatives (13a-t) of (+/-)-(5Z)-7-(3-endo-aminobicyclo[2.2.1]hept-2-exo-yl)heptenoic acid (VI) were synthesized via its methyl ester 10. Sulfonylation of 10 with 11a-t followed by saponification yielded 13a-t. Inhibitory concentrations (IC50) of the corresponding sodium salts 14a-t for platelet aggregation were measured with rat washed platelets (WP) and rabbit platelet-rich plasma (PRP). IC50 values of some derivatives for contraction of the rat aorta were also measured. The IC50 values for rat WP increased from 2.9 to 26 nM in the order of 14a, 14c, 14d, and 14b for derivatives with an arylsulfonyl residue, depending on the number of of intervening methylene groups. Methyl derivative 14e exhibited a higher IC50 value than n-hexyl derivative 14f. Substitution with a p-methyl, p-fluoro-, or p-chloro group in 14a retained or slightly reduced its IC50 value, while a p-n-pentyl or p-oxycarbonyl group augmented it significantly. The representative 14a suppressed (15S)-15-hydroxy-11,9-(epoxymethano)prosta-5(Z),13(E)-dienoic acid (U-46619) induced aggregation of human WP with an IC50 value of 7.7 nM, which corresponds well to the IC50 value of 3 nM obtained for each displacement by 14a of [3H]-U-46619 or (5Z,15 xi)-9 alpha, 11 alpha-(dimethylmethano)-15-hydroxy-16-(3-[125I]iodo- 4-hydroxyphenyl)-17,18,19,20-tetranor-13-aza-11a-carbathrombo-5-en oic acid [( 125I]-PTA-OH) bound to human WP. Synthesis of thromboxane A2 (TxA2) in human WP stimulated by thrombin was not inhibited by 14a at a concentration up to 10 microM. From these observations, the corresponding acid 13a (S-145) was concluded to be a potent TxA2 receptor antagonist.

Animals↗
PubMed1988

Validity of short-term examination for antipromoters of bladder carcinogenesis.

Various compounds were screened for antipromoter activity in bladder carcinogenesis in rats with a view to using them clinically to inhibit postoperative intravesical ectopic tumor growth of superficial papillary bladder cancer. Their inhibitions of the effect of sodium saccharin in maintaining increased agglutinability of bladder cells by concanavalin A were examined in 4-week tests. The compounds found to inhibit the effect of saccharin were alpha-tocopherol, ascorbic acid, aspirin, all-trans aromatic retinoid, alpha-difluoromethylornithine, sodium cyanate and p,p'-diamino-diphenylmethane. Considering the toxicities of some of these chemicals, ascorbic acid and alpha-difluoromethylornithine were concluded to be the most promising for future clinical trials.

Agglutination↗
PubMed1988

Use of a paracorporeal pneumatic ventricular assist device for postoperative cardiogenic shock in two children with complex cardiac lesions.

Pneumatic ventricular assist device (VAD) was utilized for cardiogenic shock after intracardiac operation in two children with complex cardiac anomalies based with single ventricle. In the first case (a 10-year-old), after a modified Fontan operation, VAD was placed between the functional left atrium and ascending aorta, serving as a "artificial single ventricle" with neither pumping chamber nor artificial support in the right side of the heart. The systemic circulation was maintained by keeping relatively high central venous pressure. In another child (a 3-year-old) who underwent repair of incompetent atrioventricular valve leaving intracardiac lesions, VAD was placed between the common atrium and ascending aorta, serving as a pump for both pulmonary and systemic circulation with regulation of pulmonary blood flow through an aortopulmonary Gore-Tex shunt. The circulatory assist with VAD was utilized for 5 and 6 days, respectively. Although weaning from the device was not feasible in both patients because of the pulmonary dysfunction, these experience showed the possible use of VAD for cardiogenic shock after surgery in patients with complex cardiac anomalies.

Assisted Circulation↗
PubMed1988

Assessment of prostacyclin and thromboxane A2 release during reperfusion after global ischemia induced by crystalloid cardioplegia--comparison between warm and cold ischemia.

The metabolites of prostacyclin (PGI2) and thromboxane A2 (TxA2), 6-keto-PGF1 alpha and thromboxane B2 (TxB2), were investigated during reperfusion (RP) following warm (37 degrees C, 60 min, n = 9) or cold (15 degrees C, 120 min, n = 11) ischemia induced by cold (4 degrees C) or normothermic (30 degrees C) K+ cardioplegia (CP) in isolated canine hearts subjected to global ischemia and RP. 6-Keto-PGF1 alpha flux was significantly higher (p less than 0.025) in the warm group at 1, 5, and 10 min of RP (4,202 +/- 1,412, 2,475 +/- 1,875, and 1,255 +/- 633 pg/g.min, mean +/- SD) compared to those in the cold group (1,504 +/- 1,245, 434 +/- 641, and 370 +/- 329 pg/g.min). TxB2 flux was small in amount compared to 6-keto-PGF1 alpha in both groups. Regarding the coronary hemodynamics, the cold group alone showed statistically significant relationships of coronary sinus blood flow to TxB2 level and TxB2/6-keto-PGF1 alpha ratio in coronary sinus blood. Also, coronary vascular resistance showed linear relations to these two parameters of the metabolites. In a supplementary experiment only with cold ischemia for 180 min, 6-keto-PGF1 alpha was released at each coronary flush-out by CP and the incremental amount showed a gradual increase during ischemia. These results indicated that significant production and release of PGI2 occurred during ischemia and RP following CP arrest and these related to the degree of myocardial damage while the response of TxA2 seemed less significant. The role of PGI2 release during RP following cardioplegic arrest was discussed.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

[Hypothalamic pituitary function in brain death patients--from blood pituitary hormones and hypothalamic hormones].

According to the report of the Health and Welfare Ministry's research committee on brain death (1985), "brain death is defined as an irreversible cessation of the total brain function including brain stem." However, in brain death patients, whether the hypothalamic function which belongs to the brain stem function has completely ceased or not is unknown. In order to evaluate the hypothalamic function in brain death patients, the blood levels of the pituitary hormones and hypothalamic hormones were measured, and anterior pituitary stimulation test with triple bolus injection (TRH 500 micrograms, LH-RH 100 micrograms, regular insulin 0.3-0.7 unit/kg) was performed. The subjects were 13 brain death patients whose clinical states fully satisfied the criteria proposed by the committee. 1) The average blood levels of anterior pituitary hormones in these brain death patients were within normal range, and that of growth hormone was more than the twice of the normal level. 2) The blood anterior pituitary hormones were detectable in almost all cases even several days after the diagnosis of the brain death. 3) LH reserve was maintained in three cases. FSH reserve was maintained in three cases. Prolactin reserve was maintained in two cases. TSH reserve was maintained in one case. 4) Blood ADH (antidiuretic hormones) were detectable in 7 cases out of 9 cases. The blood ADH level of one case, in particular, was rather high (above 10 pg/ml). 5) Histopathologically anterior pituitaries were examined in three autopsy cases. The central necrotic areas were observed in all cases, but normal pituitary tissues existed peripherally. And all anterior pituitary hormones could be recognized immunohistochemically. 6) The blood levels of the hypothalamic hormones (GRF, CRF, LH-RH) were measured in four cases. The hypothalamic hormones were detectable in all cases. In one case, the levels of GRF were within normal range even 9 or 15 days after the diagnosis of brain death.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗