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Biomedical subjects

Y Taira

Publications and source records attributed to Y Taira.

At least 91 records · Page 5Linked to original sources
PubMed1992

[A case report of ruptured mycotic aneurysm at the site of subclavian flap angioplasty].

Postoperative mycotic aneurysm of the thoracic aorta at the site of subclavian flap angioplasty (SFA) is very rare. A 6-year-old boy was admitted with a history of high fever for 10 days. He had undergone SFA at the age of 14 days and patch closure of VSD at 10 months. The chest X-ray film on admission revealed no abnormality. But, 7 days later, he suffered from frequent hemoptysis and chest X-ray film showed an abnormal mass shadow at the left upper lung field. Contrast enhanced CT scan and IV-DSA revealed a pseudoaneurysm of the aortic arch which had ruptured into the left upper lung. An extra-anatomical bypass was urgently made from the ascending aorta to abdominal aorta and the aneurysm was isolated by ligations of the aorta proximal and distal to the aneurysm. Aneurysmectomy combined with left upper lobectomy was carried out next day. Septic signs and hemoptysis dramatically improved after operation. Extra-anatomical bypass as a means of choice for the surgical treatment of the mycotic aneurysm greatly contributed to cure the severe ill patient. But a close follow up observation for the function of the graft is necessary.

Aneurysm, Infected↗
PubMed1991

Phospholipase D activity in subcellular membranes of rat ventricular myocardium.

The phospholipase D (PL D), which catalyzes the formation of phosphatidic acid (PA), was studied in rat myocardium using 14C-labelled phosphatidylcholine (PC) as an exogenous substrate. Subcellular distribution experiments indicated the presence of PL D in particulate fractions only. Different procedures for the isolation of purified cardiac subcellular organelles showed the presence of PL D in sarcolemma (SL), sarcoplasmic reticulum (SR) and mitochondria with 14-, 11- and 5-fold enrichment when compared to the homogenate value, respectively. The activity of SL PL D was observed over a narrow acid pH range with an optimum at 6.5, and it showed a high specificity for PC while phosphatidylethanolamine and phosphatidylinositol showed a low rate of hydrolysis. Under optimal conditions, PA formation was linear for a 90-min period of incubation and the reaction rate was constant for 10 to 100 micrograms SL protein in the assay medium. The SR PL D displayed properties similar to those seen with the SL PL D. In membrane fractions PL D was also found to catalyze a transphosphatidylation reaction for the synthesis of phosphatidylglycerol. Assessment of the intramembranal levels of radioactive 1,2-diacylglycerol (DAG) in the absence or presence of KF suggested the presence of an active PA phosphohydrolase activity. This study indicates that a PC-specific PL D activity is localized in different membrane systems of the myocardium and may be associated with PA phosphohydrolase to act in a coordinated manner. The functional significance of PL D-dependent formation of PA in cardiac membranes is discussed.

Animals↗
PubMed1991

The correlation between the immunohistochemical expression of DF3 antigen and serum CA15-3 in breast cancer patients.

The immunohistochemical expression of DF3 antigen and serum concentrations of CA15-3, a breast carcinoma-associated antigen recognized by the monoclonal antibodies (MAbs) 115D8 and DF3, was investigated in breast cancer patients. The levels of serum CA15-3 in 23 primary breast cancer patients did not correlate to the percentage cytoplasmic reactivity of MAb DF3 with the carcinoma cells in tissue specimens from each respective patient. In 17 patients who subsequently developed metastatic breast cancer, however, the serum CA15-3 concentrations generally correlated well to the cytoplasmic reactivity of MAb DF3 with the carcinoma cells in specimens obtained at initial biopsy or mastectomy. Elevated levels of serum CA15-3 were seen in metastatic breast cancer patients when the carcinoma cells in their primary specimens expressed enhanced levels of cytoplasmic DF3 antigen. The results of this study suggest that the immunohistochemical demonstration of DF3 antigen in tissue specimens, together with the periodical measurement of circulating CA15-3 antigen, may be important for monitoring the clinical course of breast cancer patients.

Antibodies, Monoclonal↗
PubMed1991

Dumbbell neurogenic tumor of the mediastinum: a report of three cases undergoing single-staged complete removal without thoracotomy.

Of a total thirteen patients who underwent surgery for a neurogenic tumor in the posterior mediastinum 4 (30.8 per cent) presented with dumbbell type development of the tumor. Along with a comparatively greater incidence in the number of cases of dumbbell neurogenic tumors in the posterior mediastinum, resection has also recently become more popular, necessitating the establishment of a standard operative approach for this type of tumor. We successfully removed dumbbell neurogenic tumor from the posterior mediastinum in our 3 most recent cases via a dorsal approach by virtue of a laminectomy and resection of a small portion of the neighbouring rib root without opening the parietal pleura at all. These three patients were a 14 year old female, a 54 year old male and a 68 year old female, respectively, and the largest diameter in cm and level of origin of the tumors were 5.5 at Th 1 in case 1, 3.0 at Th 2 in case 2 and 3.7 at Th 11 in case 3. The operative approach described herein was easy to perform, felt secure and was less invasive and better tolerated by the patients than the thoracotomy approach. Avoiding a thoracotomy in such cases has many advantages to enumerate, but does not seem to have been clearly aimed at by others to date. We therefore propose our technique as a standard approach for dumbbell neurogenic tumors in the posterior mediastinum.

Adolescent↗
PubMed1991

Increased sarcolemmal Ca2+ transport activity in skeletal muscle of diabetic rats.

Sarcolemmal membranes were isolated from skeletal muscle by a sucrose density gradient method from rats with diabetes induced by a streptozotocin injection (65 mg/kg iv). The activities of Na(+)-dependent Ca2+ uptake and Ca2(+)-stimulated adenosine-triphosphatase (ATPase) in the sarcolemmal fraction from diabetic rats was higher than those from the control animals. These changes were apparent at various times of incubation (1-10 min) as well as at different concentrations of free Ca2+ (10(-7) to 10(-5) M) and developed during the third and/or fourth weeks after streptozotocin injection. ATP-dependent Ca2+ uptake in the sarcolemmal vesicles was also increased at 28 and 56 days after inducing diabetes. Treatment of diabetic animals with insulin for 14 days reversed the changes in Ca2+ transport activities toward the control levels. Sarcolemmal Mg2(+)-ATPase and Na(+)-K(+)-ATPase activities remained unchanged in diabetic preparations. Furthermore, no difference in the sarcolemmal phospholipid composition and sodium dodecyl sulfate-gel electrophoretic pattern was evident between the control and experimental groups. These results indicate a higher activity of the sarcolemmal Ca2+ transport, which may be associated with hyperfunction of the skeletal muscle in diabetic rats.

Animals↗
PubMed1990

Stimulation of phospholipid N-methylation by isoproterenol in rat hearts.

Phosphatidylethanolamine (PtdEtn) N-methyltransferase activities were studied in rat heart sarcolemmal and sarcoplasmic reticular fractions after a single intraperitoneal injection of isoproterenol (0.5-5.0 mg/kg). Three active sites (I, II, and III) for PtdEtn N-methylation were assayed by measurement of [3H]methyl group incorporation from 0.055, 10, and 150 microM S-adenosyl-L-[methyl-3H]methionine into membrane PtdEtn molecules. Total methylation activity for catalytic site I of both sarcolemma and sarcoplasmic reticulum was stimulated within 2 minutes by isoproterenol in a dose-dependent manner. Although the increased methyltransferase activity in sarcoplasmic reticulum was normalized at 10 minutes, the enzyme activity in sarcolemma was normalized at 5 minutes but was again increased at 10-30 minutes after isoproterenol injection. No changes in response to isoproterenol were seen for site II and III N-methylation activities in either membrane. Individual N-methylated phospholipids (phosphatidyl-N-monomethylethanolamine, phosphatidyl-N,N-dimethylethanolamine, and phosphatidylcholine), which specifically formed at each site, showed similar behavior. Pretreatment of the animals with a beta-blocking drug, atenolol, for 2 days prevented the isoproterenol-induced changes in hemodynamic parameters and sarcolemmal methylation without affecting the enhanced methylation activities in sarcoplasmic reticulum. In vitro addition of cyclic AMP-dependent protein kinase (catalytic subunit) plus Mg-ATP enhanced methyltransferase activities in sarcolemma and sarcoplasmic reticulum from control hearts by 2.7- and 2.3-fold, respectively; however, under the same in vitro conditions, only about 20% activation was seen in both subcellular membranes isolated from the heart of isoproterenol-injected animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1990

Alterations in phospholipid N-methylation of cardiac subcellular membranes due to experimentally induced diabetes in rats.

Phosphatidylethanolamine N-methylation was examined in cardiac subcellular membranes after inducing chronic experimental diabetes in rats (65 mg streptozotocin/kg, i.v.). The incorporation of radiolabeled methyl groups from S-adenosyl-L-methionine in diabetic sarcolemma was significantly depressed at all three catalytic sites (I, II, and III) of the methyltransferase system. An increase in methyl group incorporation was evident at site I without any changes at sites II and III in diabetic sarcoplasmic reticulum and mitochondria. Similar changes were also seen for the individual N-methylated lipids (monomethyl-, dimethylphosphatidylethanolamine, and phosphatidylcholine) specifically formed at each catalytic site in all cardiac membranes from diabetic animals. These alterations in N-methylation were reversible by a 14-d insulin therapy to the diabetic animals. In the presence of 10 microM ATP and 0.1 microM Ca2+, N-methylation was maximally activated at site I in both control and diabetic sarcolemma and sarcoplasmic reticulum, but not in mitochondria. Incubation of cardiac membranes with of S-adenosyl-L-methionine showed that Ca2(+)-stimulated ATPase activities in both sarcolemma and sarcoplasmic reticulum were augmented; however, the activation of diabetic sarcolemma was lesser and that of diabetic sarcoplasmic reticulum was greater in comparison with the control preparations. These results identify alterations in phosphatidylethanolamine N-methylation in subcellular membranes from diabetic heart, and it is suggested that these defects may be crucial in the development of cardiac dysfunction in chronic diabetes.

Animals↗
PubMed1990

Effects of in vivo pretreatment with various barbiturates on anaerobic halothane metabolism in rat liver microsomes.

The effects of in vivo pretreatment with phenobarbital (PB), thiopental (TP), thiamylal (TA), pentobarbital (PT), and secobarbital (SB) on hepatic microsomal enzymes, and the effects on anaerobic halothane dehalogenation, aminopyrine N-demethylation, and aniline hydroxylation in the microsomes were studied in male Wistar rats. Three hundred twenty mumol/kg (0.1 ml) of PB, TP, TA, PT, SB, or 0.1ml of 0.9% saline were administered daily, intramuscularly, for periods of one day up to ten days. Daily administration of PB, TP, TA, or PT induced cytochrome P-450, NADPH-cytochrome P-450 reductase and/or cytochrome b5. However, administration of SB did not induce these enzymes. The potency of these enzyme inductions ranged in descending order as follows: PB, TP, TA, and PT. After five days of daily administration of PB, TP, or TA, the production of the anaerobic halothane metabolite, CDFE, increased to 187%, 134%, and 130% of the control, respectively. The production of another halothane metabolite, CTFE, likewise increased to 197%, 168%, and 163%. However, pretreatment with PT or SB had no effect on anaerobic halothane dehalogenation. Aminopyrine N-demethylation also increased after five days of daily administration of PB, TP, and TA. However, aniline hydroxylation decreased after five days of daily administration of TA. Other barbiturates had no effect on aniline hydroxylation. In this study we showed that whereas PT and SB did not enhance anaerobic halothane dehalogenation, PB, TP and TA did. We conclude that not only PB, and also TP and TA, may be enhancing factors in halothane hepatotoxicity. We recommend that, if barbiturates are necessary, SB and PT be used in the preadministration of halothane anesthesia.

Anaerobiosis↗
PubMed1990

[Effects of intratracheal lidocaine spray on circulatory responses to endotracheal intubation].

The effect of intratracheal lidocaine spray (0.5, 1.0, 2.0 mg.kg-1) on blood pressure and heart rate changes to endotracheal intubation was evaluated in 20 ASA I-II patients. After thiamylal induction, 15 patients received lidocaine spray with LTA kit. Mean arterial blood pressure and heart rate were recorded for 10 min every 30 sec and analysis of plasma lidocaine concentrations were also performed. In the control group, mean arterial blood pressure increased significantly compared with the pre-anesthetic values for one min, and with all spray groups at one min after intubation. Heart rate increased significantly at 30 sec after intubation only in the control group. Since the plasma lidocaine concentrations at intubation were below 1.5 micrograms.ml-1, we conclude that intratracheal lidocaine spray depresses the circulatory response to intubation by its local surface analgesic effect.

Administration, Inhalation↗
PubMed1990

[Results of pulmonary resections in elderly patients with primary lung cancer].

Forty-one patients over the age of 70 years, who had been operated upon for a primary lung cancer during 13 years until August, 1988, were reviewed. There were 32 males and 9 females, among whom the oldest was an 85-year-old male. These patients composed of 28.7% of the patients who had undergone a resectional lung surgery due to a primary lung cancer during the same period of time. These included 26 patients of stage I, 11 of IIIA, 3 of IIIB and 2 of IV. Twenty-two of them were with a squamous cell carcinoma, 18 with an adenocarcinoma, and one with a small cell carcinoma. Thirty-two patients underwent a lobectomy, including two undergoing a sleeve lobectomy. Three patients underwent a left pneumonectomy, and seven underwent a segmentectomy or a wedge resection. A combined chest wall resection was done in 5 of them. One patient underwent the second surgery for a metastasis to the contralateral lung following a left pneumonectomy. Our safety criteria of pulmonary functions for surgery were as follows; a predicted postoperative %VC greater than 40% for any type of pulmonary resection, a preoperative FEV1.0 greater than 1,000 ml for lobectomy and that greater than 1,300 ml for left pneumonectomy. These criteria were identical to those for patients younger than 70 years of age. But some patients even with respiratory functions slightly less than these lower limits did tolerate lobectomies or pneumonectomies. The latter patients, however, cleared what we call "one-flight test" as well as the other patients did.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1989

Alterations of phosphatidylethanolamine N-methylation in rat heart by quinidine.

To elucidate the molecular mechanism underlying the adverse depression of myocardial contractility observed during antiarrhythmic therapy of quinidine, we investigated its action on the phosphatidylethanolamine N-methyltransferase (EC 2.1.1.17) activities of cardiac subcellular membranes. Rat heart sarcolemma, mitochondria, and microsomes (sarcoplasmic reticular fragments) were isolated, and the three catalytic sites for N-methylation activities were examined with 0.055 (site I), 10 (site II), and 150 (site III) microM concentrations of S-adenosyl-L-[methyl-3H]methionine as a methyl donor. Total methyl group incorporation into sarcolemmal phosphatidylethanolamine was depressed by 10(-6)-10(-3) M quinidine at sites II and III. The activity of site I was stimulated at low (10(-9) M) concentrations and inhibited at high concentrations of the drug. A similar behaviour was observed with procainamide, although the inhibitory effect was less pronounced and was not additive with quinidine. Quinidine-induced inhibition was associated with a depression of Vmax, while the apparent affinity for S-adenosyl-L-methionine was unaltered. Analysis of individual methylated phospholipids confirmed inhibition by quinidine at sites II and III in sarcolemma. Microsomal phosphatidylethanolamine N-methylation was affected by 10(-6) M quinidine only at site II, whereas no changes were noted in mitochondria. Quinidine also inhibited both the positive inotropic response and concomitant increase in tissue N-methylated phospholipids observed upon L-methionine perfusion of rat heart. These results suggest that quinidine alters the intramembranal level of N-methylated phospholipids, and this may serve as a biochemical mechanism contributing to its negative inotropic effect.

Animals↗
PubMed1989

Comparison of serum assays for TAG-72, CA19-9 and CEA in gastrointestinal carcinoma patients.

Tumor-associated glycoprotein (TAG-72) has been shown to be expressed in a wide variety of epithelial malignant tissues. We have investigated serum levels of TAG-72 antigen in patients with gastrointestinal cancer with a solid phase radioimmunometric assay (RIA), CA72-4, utilizing murine monoclonal antibodies CC49 and B72.3 which recognize the TAG-72 antigen. Elevated levels of serum TAG-72 antigen were found in 48% of 56 gastric carcinoma patients and 67% of 45 colorectal carcinoma patients. The serum concentrations of TAG-72 were compared to those of CA19-9 and CEA. The positive rates of CA19-9 in gastric carcinoma and colorectal carcinoma patients were 29% and 54%, and those of CEA were 52% and 60%, respectively. Elevated serum levels of TAG-72, CA19-9 and CEA were observed in 7%, 14% and 24%, respectively, of patients with benign disease, thus indicating a preferential expression of TAG-72, compared to CA19-9 and CEA, in gastrointestinal carcinoma patients versus in patients with benign disorder. A cocktail of CA72-4, CA19-9 and CEA RIAs increased positive rates to 68% in sera of gastric cancer patients and 84% in sera of colorectal cancer patients. Combination assays using CA72-4, CEA and CA19-9 RIAs for patients with benign gastrointestinal disorder, however, also increased the positive rate to 31%. These results indicate that CA72-4, CA19-9 and CEA RIAs may be complementary in detecting circulating tumor-associated antigens. It must be emphasized, however, that interpretation of the data provided by the combination serum assays requires careful consideration.

Antibodies, Monoclonal↗
PubMed1988

Increased SR phospholipid N-methylation in skeletal muscle of diabetic rats.

Phosphatidylethanolamine (PE) N-methylation was studied in skeletal muscle sarcoplasmic reticulum (SR) 6 wk after the induction of experimental diabetes in rats by an injection of streptozocin (65 mg/kg iv). A significant increase in the incorporation of radiolabeled methyl groups from S-adenosyl-L-methionine (AdoMet) into intramembranal PE was observed in diabetic preparations at 0.055 microM AdoMet, whereas the methylation activity was unaltered at 10 and 150 microM AdoMet concentrations. The increase in PE N-methylation activity was not evident until 28 days after streptozocin injection and was normalized by a 2-wk treatment of diabetic animals with insulin. In the presence of 10 microM of ATP and low concentrations of Ca2+ (0.1 microM), PE N-methylation was maximally activated, but the percent increase was similar in control, diabetes, and insulin-treated diabetes; at 100 microM Ca2+, however, N-methylation activity was depressed only in diabetic preparations. Calmodulin inhibitors such as compound 48/80 and calmidazolium (compound R24571) abolished the effect of Ca2+ and ATP on PE N-methylation in all three groups. Sarcolemmal (SL) PE N-methylation in diabetic skeletal muscle was also found to be increased at 0.055 microM AdoMet. The results suggest that intramembranal calmodulin may participate in regulating PE N-methylation in skeletal muscle membranes, but it may not be responsible for the high N-methylation activity in diabetic rats.

Adenosine Triphosphate↗
PubMed1988

[Levels of circulating tumor-associated glycoprotein (TAG-72) in patients with carcinoma using a novel tumor marker, CA 72-4].

CA72-4 is a novel quantitative immunoradiometric assay system utilizing two monoclonal antibodies CC-49 and B72.3, which recognize a tumor-associated glycoprotein (TAG-72). We have utilized the CA72-4 RIA kit to measure serum levels of TAG-72 in 205 patients with carcinoma and 192 patients without carcinoma. The cut-off value (4.0 U/ml) was obtained according to the levels and the distribution of CA72-4 in 468 healthy individuals. The positive rates in 82 patients with gastric cancer, 55 with colorectal cancer, 24 with pancreatico-choledochal cancer, 36 with breast cancer, and 3 with ovarian cancer were 52%, 55%, 46%, 39%, and 67%, respectively. Fifty percent of the sera from 205 patients with carcinoma demonstrated increased levels of CA72-4, whereas only 10% of the sera from 192 patients without evidence of malignancy showed levels more than 4.0 U/ml. The average level of serum CA72-4 in the patients with carcinoma was 38.6 U/ml, much higher than that (2.7 U/ml) in patients without malignancy. The patients with gastrointestinal cancer at advanced stages or at recurrence showed higher levels of serum CA72-4 than the patients with cancer at early stages. These results thus indicate that CA72-4 is clinically useful as a novel tumor marker, especially for monitoring serum levels of TAG-72 in patients with gastrointestinal cancer, breast cancer, ovarian cancer and other epithelial malignancies.

Antigens, Neoplasm↗
PubMed1987

The role of mediastinal and multi-organ CT scans in staging presumable surgical candidates with non-small-cell lung cancer.

In order to evaluate the role of CT scan and bone scan in staging patients with non-small-cell lung cancer presumably indicated for surgery, 70 consecutive patients who underwent thoracotomy were reviewed. Most of them received mediastinal and multi-organ (brain, liver and adrenal) CT scans and a bone scan. In the most recent 40 of the 70 patients, CT findings of the mediastinal lymph nodes were compared to the pathology following complete sampling. The overall accuracy of the mediastinal CT was 60.0 per cent (12 true positive and 12 true negative), but the negative predictable value was 12/(12 + 3) or 80.0 per cent, whereas 3 were false negatives though they showed an acceptable postoperative course. Sixteen out of 21 patients with one, or at the most, three enlarged nodes detected on CT also did well postoperatively and retrospectively, were considered not to have required mediastinoscopy. A group of patients showing no, or at the most, three enlarged mediastinal lymph nodes on CT may be considered as candidates for surgery even without mediastinoscopy. Multi-organ survey by means of CT was believed cost-ineffective and omittable. Bone scan however, retrospectively detected three true positives among 20 patients with a positive uptake, so that it cannot be omitted out of hand, though further examination of this point is required.

Aged↗
PubMed1987

Altered contractile proteins in skeletal muscle of diabetic rats.

The ATPase activity of myofibrils and myosin from hindlimb muscle was investigated in animals 4 wk after the induction of diabetes by an intravenous injection of streptozotocin (65 mg/kg). Ca2+-stimulated ATPase in myofibrils was increased in diabetic muscle at various times of incubation (1-7 min) as well as at different concentrations of free Ca2+ (10(-7)-10(-5) M Ca2+). Such an increase in Ca2+-stimulated ATPase was evident as early as 1 wk after streptozotocin injection, but Mg2+-ATPase activity remained unaltered. Treatment of diabetic animals with insulin Ca2+-ATPase and actin-activated ATPase activities of pure myosin were similarly increased in diabetic muscle. Myosin ATPase was also activated by K+- or NH4+-EDTA; these responses were more in diabetic muscle. However, sodium dodecyl sulfate gel electrophoresis failed to reveal differences in the patterns of contractile proteins, and pyrophosphate gels did not show significant changes in myosin isozyme patterns between diabetics and controls. The results of this study demonstrate an activation of contractile protein ATPase of skeletal muscle in diabetes and seem to indicate that such an alteration may be responsible for enhanced contractile function of skeletal muscle in this disease.

Actins↗
PubMed1987

Transmural anoxic wave front and regional dysfunction during early ischemia.

The relative time courses of early changes in myocardial metabolism and function during anoxia, global ischemia, and regional ischemia were compared in isolated rat hearts. Transmural anoxic wave front was determined with NADH fluorescence photography, and oxygen saturation of myoglobin and dynamic systolic wall thickening were measured with spectrophotometry of light transmitted through the left ventricular free wall. In all three treatments, anoxic wave front first appeared in the subendocardium and reached the epicardial half of the myocardium in 10 s, when oxygen saturation of myoglobin decreased by 50% and tissue ATP and creatine phosphate remained at aerobic levels. During this period, systolic wall thickening decreased gradually in anoxia and global ischemia, whereas a marked decrease in systolic wall thickening and appearance of dyskinesia (wall thinning) occurred in regional ischemia. Thus the early extension of anoxic wave front and metabolic changes are similar with all three treatments, and dyskinesia, observed only in case of regional ischemia, occurs when the inner half is ischemic or anoxic.

Animals↗