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M Aiba

Publications and source records attributed to M Aiba.

At least 19 recordsLinked to original sources
PubMed1998

[Blood flow velocity in the ophthalmic artery measured by Doppler ultrasonography during cardiopulmonary bypass--usefulness for cerebral perfusion monitor].

Brain blood flow is supplied from the internal carotid artery, and the ophthalmic artery is the first branch of the internal carotid artery. We studied how blood flow velocity in the ophthalmic artery (OAV) changes during cardiopulmonary bypass (CPB) and investigated whether it can be used to monitor brain blood flow during CPB. In 13 open heart surgeries in adults, OAV and blood flow velocity in the common carotid artery (CAV) were measured with Doppler ultrasonography, and blood flow volume in the brachiocephalic artery (BA flow) was measured simultaneously with an electromagnetic flow meter. Maximal blood flow velocity in the ophthalmic artery (OAVmax) and the common carotid artery (CAVmax) were 0.27 +/- 0.13 m/sec and 0.64 +/- 0.40 m/sec, BA flow was 486 +/- 226 ml/min before CPB. When CPB pump flow was varied (2.4, 2.2, 2.0, 2.2, 2.4 l/min/m2), the parameters during and after CPB changed as follows (as percentage of pre-CPB levels): OAVmax, 58.1%, 50.9%, 37.6%, 49.4%, 64.7%, 108.4%; CAVmax, 67.0%, 58.0%, 48.2%, 113.6%, 105.5%, 134.3%; and BAflow, 87.3%, 39.8%, 53.9%, 50.5%, 95.0%, 159.8%. Our results indicate that OAVmax more accurately reflects changes in pump flow than does CAVmax and BA flow. Because vessel resistance in the ophthalmic artery was small during CPB, OAVmax was thought to be determined mainly by CPB pump flow. OAVmax was useful for monitoring brain blood flow during CPB.

Adult↗
PubMed1998

Prognostic value of hypercapnia in patients with chronic respiratory failure during long-term oxygen therapy.

Hypercapnia observed in patients with chronic respiratory failure may not be an ominous sign for prognosis when they are receiving long-term oxygen therapy (LTOT). In this study, we selected 4,552 patients with chronic obstructive pulmonary disease (COPD) and 3,028 with sequelae of pulmonary tuberculosis (TBsq) receiving LTOT from 1985 to 1993 throughout Japan and prospectively analyzed their prognoses. The hypercapnic patients (PaCO2 >= 45 mm Hg) had a better prognosis than the normocapnic patients (35 <= PaCO2 < 45 mm Hg) for TBsq, but no difference was found between the two groups with COPD. Furthermore, Cox's proportional hazards model revealed that in TBsq hypercapnia was an independent factor for favorable prognosis, and that the relative risk for mortality was 0.76 in patients with 45 <= PaCO2 < 55 mm Hg, 0.64 for those with 55 <= PaCO2 < 65 mm Hg, and 0. 49 for patients with PaCO2 >= 65 mm Hg against normocapnic patients. This favorable effect of hypercapnia in TBsq was particularly apparent in the patients without severe airway obstruction. Even a rise of 5 mm Hg or more in PaCO2 over the initial 6- to 18-mo follow-up period was not associated with poor prognosis in TBsq, although it was in COPD. From these findings, we conclude that hypercapnia should not be generally considered an ominous sign for prognosis in those patients who receive LTOT.

Aged↗
PubMed1997

Spontaneous regression of primary intracranial germinoma. A case report.

BACKGROUND: Testicular seminomas are well known to regress spontaneously at a higher incidence than other tumors. To date, there have been no reports of spontaneous regression of an intracranial germinoma, although these tumors are histologically identical to testicular seminomas. METHODS: The authors present a patient with a primary intracranial germinoma that regressed spontaneously. RESULTS: A 21-year-old man was admitted to the study facility with acute onset of headache and vomiting. He had a 3-year history of polydipsia and polyuria. Computed tomography (CT) demonstrated a large tumor in the third ventricle, accompanied by hydrocephalus. He underwent ventriculoperitoneal shunt placement on the second day of hospitalization. A CT scan obtained on the fifth postoperative day demonstrated a remarkable decrease in tumor size. Because serial magnetic resonance imaging (MRI) demonstrated a gradual decrease in tumor size, tumor resection was not performed at that time. The patient was discharged and followed with MRI. The tumor continued to regress for more than 2 months. The patient was readmitted due to tumor regrowth, confirmed by MRI 4 months after the initial admission, despite the absence of symptom exacerbation. Two weeks later, the suprasellar portion of the tumor was resected through a right frontotemporal craniotomy. The histopathologic diagnosis was a germinoma. No concurrent tumors were found on whole body examination. The residual tumor gradually regressed after conventional radiation therapy and there has been neither tumor recurrence nor metastasis to date. CONCLUSIONS: Although the precise cause of the transient partial regression is unknown, this case indicates that, like their testicular counterparts, intracranial germinomas may on occasion spontaneously regress.

Adult↗
PubMed1997

Left ventricular fibroma in an aged patient: report of a case.

We report herein the case of a 77-year-old man with a left ventricular tumor originating from the papillary muscle of the left ventricular wall, in whom a successful tumor resection with mitral valve replacement was performed. The pathological diagnosis of the tumor was confirmed as cardiac fibroma. His postoperative course was uneventful and he is currently well with no signs of recurrence 2 years after surgery.

Aged↗
PubMed1997

Clinicopathologic study of angiogenesis in Japanese patients with breast cancer.

To evaluate the clinicopathologic significance of angiogenesis as a prognostic factor and the objective methods for evaluating angiogenesis, we immunohistochemically stained a representative section of breast tumors with factor VIII-related antigen staining. There were 109 patients with primary breast cancer from 1971 to 1979. The two methods of identifying angiogenesis were the average microvessel count per square millimeter (AMC) and the highest microvessel count per square millimeter (HMC). There was no relation between microvessel count (AMC or HMC) or age, menopausal status, clinical tumor size (T), histologic classification, nuclear grade, node status, histologic grade (HG), mitosis index, or lymphatic invasion (LI). There was a relation between microvessel count and blood vessel invasion (BVI) (HMC:p = 0.0007) and tumor necrosis (TN) (HMC:p = 0.0050). Univariate analysis showed that AMC or HMC was a statistically significant predictor of overall survival in all patients (p = 0.0086 and p = 0.0307, respectively). Multivariate analysis showed that AMC was an independent predictor of node status when we fitted a model with node status, BVI, and either AMC or HMC; but HMC was not independent. However, when we fitted a model including all 11 of the other indicators and AMC or HMC, the node status, HG, and LI were independent predictors, but AMC and HMC were not. Although AMC was a better method than HMC for evaluating angiogenesis, we cannot confirm angiogenesis as a significant independent prognostic factor associated with long-term survival in Japanese breast cancer patients.

Adult↗
PubMed1997

MIB1-determined proliferative activity in intraductal components and prognosis of invasive ductal breast carcinoma.

Intraductal components of breast carcinoma may have prognostic significance. In this study, we divided 181 invasive ductal breast carcinomas into comedo and non-comedo groups based on intraductal component morphology, and differences between the two groups in clinicopathological variables, including proliferative activity and survival, were assessed. Proliferative activity was evaluated by using MIB1 antibody, which reacts with the cell-proliferation-associated Ki-67 antigen, and was expressed as the number of MIB1-positive nuclei per 1000 cancer cells in intraductal components (MIB1 labeling index). We also investigated which variables had an impact on survival. The comedo group showed a significantly higher MIB1 labeling index than the non-comedo group (P < 0.0001). The differences in disease-free and overall survival between the two groups were not significant (P = 0.2477, P = 0.2069). Multivariate analysis of the entire series showed the MIB1 labeling index to be an independent prognostic factor predicting both disease-free survival and overall survival (P = 0.0160, P = 0.0035). When multivariate analysis was repeated separately for the non-comedo and comedo groups, the MIB1 labeling index remained the most important variable predicting disease-free and overall survival in the non-comedo group (P = 0.0122, P = 0.0040). Moreover, non-comedo patients with a high MIB1 labeling index had significantly shorter disease-free and overall survival than those with a low MIB1 labeling index (P = 0.0040, P = 0.0402). These findings imply that MIB1-determined proliferative activity of intraductal components is an independent predictor of survival, and is the most important predictor in non-comedo cases.

Adult↗
PubMed1996

Pituitary choristoma composed of corticotrophs and adrenocortical cells in the sella turcica.

A pituitary tumour composed of well-differentiated corticotrophs and adrenocortical cells is reported. Sections of the tumour revealed a mixture of small round cells with amphophilic or basophilic periodic acid-Schiff (PAS)-positive cytoplasm and large spherical and oval cells with abundant, granular, partly vacuolated PAS-negative cytoplasm. The small cells contained type 1 cytokeratin-positive microfilaments, numerous 250-500 nm endocrine-type secretory granules immunoreactive for adenocorticotropic hormone (ACTH) and beta-lipotropin. The large cells possessed ample cytoplasm filled with abundant vesicular smooth endoplasmic reticulum, numerous mitochondria possessing tubulovesicular cristae and frequent dense bodies. They lacked the features of pituitary endocrine cells or folliculostellate cells and were found to contain a panel of steroidogenic dehydrogenases and hydroxylases. The tumour was classified as a choristoma, in which two distinct cells types, corticotrophs and adrenocortical cells, were mixed. We suggest that, under continued ACTH stimulation, umcommitted stem cells may differentiate into adrenocortical cells. Alternatively, the presence of adrenocortical cells may be the result of heterotopia.

Adolescent↗
PubMed1996

Clinicopathologic features associated with long-term survival in node-negative breast cancer patients.

This study was undertaken to assess blood vessel invasion (BVI) and other histologic features to determine the best method of histologic prognosis in node-negative breast cancer patients. The prognostic significance of the clinico-pathological findings was evaluated in 70 patients with node-negative breast cancer among 135 patients operated on between 1971 and 1981. The prognostic factors investigated included BVI, peritumor lymphatic invasion, clinical tumor size, nuclear grade, histological grade, mitotic grade, and tumor necrosis. BVI was detected by factor VIII-related antigen and elastica van Gieson staining. BVI-negative patients had a 20-year cumulative survival of 93.7%, versus 74.7% for BVI-positive patients (P = 0.0294). The clinical tumor size also correlated well with prognosis (P < 0.001). However, the other histologic features did not correlate with a poor prognosis. Moreover, we retrospectively examined the effect of postoperative chemotherapy for patients with BVI and T3, and the prognosis of those given chemotherapy seemed to be better than that of those who were not. Tumors measuring more than 51 mm and BVI may thus represent adverse prognostic factors in node-negative breast cancer patients.

Adult↗
PubMed1996

Demonstration of activin in normal pituitary and in various human pituitary adenomas by immunohistochemistry.

Inhibins and activins have been known to modify the secretion of various pituitary hormones. To study whether inhibins and activins are present in human pituitary tissues, immunohistochemical studies with antisera to activin A and inhibin alpha subunit were performed on 9 human pituitary adenoma tissue specimens and one sample of normal pituitary tissue adjacent to one adenoma. Activin immunoreactivities were demonstrated in the cytoplasms of one GH and one PRL and two non-functioning adenomas and one normal pituitary tissue, but they were negative in one PRL, one ACTH, one FSH and two non-functioning adenomas. Thus, the presence and absence of activin in the same type of adenoma in regard to hormone production, suggested that the difference in immunostaining simply reflected the difference in the activin concentration. In contrast to this, inhibin alpha subunit immunoreactivity was not found in any of the tissues studied. These data suggested a local synthesis of activin in the normal pituitary as well as various kinds of pituitary adenoma tissues and its local role in the human pituitary gland.

Activins↗
PubMed1996

[Isolated rupture of the ventricular septum caused by nonpenetrating trauma--a case report of operation in acute stage].

We experienced a case of the isolated ventricular septal defect due to nonpenetrating chest trauma. The patient was 22-year-old male who hit his chest with a steering wheel on car accident. The echocardiogram examined on the next day revealed a ventricular septal defect. Four days after the injury, intracardiac repair was performed. On cardiopulmonary bypass the ventricular perforation (35 x 35 mm size) located in the muscular portion near the apex was closed with a PTFE and equestrian pericardial patch. Postoperative cardiopulmonary function could improve enough to wean from IABP and respiratory support. However, the patient died on the fifth postoperative day of severe hepatic failure due to profound shock persisted after the accident.

Accidents, Traffic↗
PubMed1995

Spontaneous rupture of the iliac vein: report of a case.

We report a rare case of a spontaneous rupture of the iliac vein which was then surgically treated with good results. A 66-year-old woman was admitted complaining of leg swelling and lower abdominal pain. On the 3rd day after admission, an operation was performed because of a gradually increasing hematoma in the retroperitoneal space. Laparotomy revealed a 17 mm longitudinal tear on the anterior surface of the left external iliac vein with a thrombus inside the lumen. Most of the previously reported 14 cases of this nature have required emergency operations.

Aged↗
PubMed1995

Gender effect on prognosis of patients receiving long-term home oxygen therapy. The Respiratory Failure Research Group in Japan.

Although long-term home oxygen therapy (LTOT) certainly prolongs survival, it is not known whether this advantageous effect is similar for both sexes. In this study, we analyzed sex-related differences in survival based on a very large population that had received LTOT from 1986 to 1993. A total of 9,759 patients with chronic obstructive pulmonary disease (COPD), sequelae of tuberculosis (TBsq), and chronic interstitial pneumonia (IP) were selected in 1,212 medical institutions for analysis of survival rates. The survival rates of both sexes were compared with each other using the Cutler-Ederer Method. Despite higher PaCO2 at the beginning, the survival rate of women was significantly better than that of men in these three disease categories. Cox's proportional hazards analysis further confirmed the gender effect on survival by eliminating the effects of age, PaO2, PaCO2, %VC, and FEV1/FVC. The mean survival periods of the women who died during follow-up periods were also significantly longer than those of men (0.41 yr in COPD, 1.84 yr in TBsq, and 0.78 yr in IP). From these findings, we conclude women have a better prognosis than men when they start receiving LTOT, regardless of the cause of respiratory failure.

Female↗
PubMed1995

Lysine vasopressin stimulation of cortisol secretion in patients with adrenocorticotropin-independent macronodular adrenal hyperplasia.

We present two patients with Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia who showed marked plasma cortisol response to lysine-8-vasopressin (LVP) injection (from 930 and 731 pmol/L to 2177 and 1920 pmol/L, respectively), while plasma ACTH levels remained undetectable. The ACTH independence of cortisol secretion in the two patients was determined from the following endocrinological findings. Plasma cortisol levels were not increased by corticotropin-releasing hormone injections and were not suppressed by high dose (16 mg) dexamethasone administrations. The plasma ACTH levels, measured by two independent sensitive immunoassays, were persistently undetectable even after corticotropin-releasing hormone injection, metyrapone administration, and bilateral adrenalectomy. The particular pathological finding of the two cases, atrophic lesions in nonnodular parts of the adrenal cortexes, also indicated ACTH independence of the macronodular hyperplasia. In vitro examination revealed a direct effect of LVP on cortisol secretion from the adrenal cells of the macronodules. We also examined seven patients with Cushing's syndrome caused by adrenal adenoma and found a statistically significant plasma cortisol response to LVP injection. The direct effect of LVP was also demonstrated in cultured adenoma cells. In conclusion, we discovered a direct adrenal effect of LVP on cortisol secretion in patients with ACTH-independent macronodular hyperplasia and, to a lesser extent, in patients with cortisol-producing adrenal adenoma. The cortisol response to LVP may serve to facilitate their diagnosis and choice of therapy.

17-Hydroxycorticosteroids↗
PubMed1995

Characteristics of aldosterone-producing adenoma responsive to upright posture.

A small subgroup of primary aldosteronism due to aldosteronoma, named aldosterone-producing renin-responsive adenoma (AP-RA), has been reported to masquerade as idiopathic hyperaldosteronism (IHA) because of the responsiveness of the plasma aldosterone concentration (PAC) to upright posture (UP). We found two patients with AP-RA in 19 patients with aldosteronoma who were examined by UP stimulation and were treated surgically. In 17 patients with typical aldosterone-producing adenoma (APA), PAC decreased or increased only slightly (less than 200% of the basal level); in contrast, it increased to over 300% of the basal level in two patients with AP-RA. The two groups were comparatively studied as to their hormonal levels, adrenal computed tomography (CT) scan and histological findings in order to clarify the characteristics of AP-RA. Basal PAC was within the normal range (11.1 and 13.0 ng/dl) in AP-RA but in APA it ranged from 14.8 to 58.1 ng/dl with a mean of 32.3 +/- 2.7 ng/dl. The diameters of the adenoma in AP-RA were apparently smaller (6 and 9 mm) than those in APA ranged from 10 to 25 mm with a mean of 15.5 +/- 1.1 mm. After a contrast medium was injected at CT scan, the density of the normal adrenal gland adjacent to the adenoma increased but that of the adenoma did not in APA, making a clear distinction between the adenoma and the gland. On the other hand, the density of the adenoma and gland increased to almost the same degree in AP-RA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Neoplasms↗
PubMed1995

[Coronary artery bypass grafting for a patient with left ventricular ejection fraction of 16%: a case report and review of the Japanese literature].

A 65-year-old man with left ventricular ejection fraction (LVEF) of 16% successfully underwent coronary artery bypass grafting (CABG). CABG used to be contraindicative for patients with LVEF below 20%. However, such patients are recently involved to indication of CABG if viability of the myocardium is proved. We consider CABG is indicated for a patient who keeps a sufficient cardiac output despite a low level of LVEF. Intraaortic balloon pumping which was started immediately after the induction of anesthesia was effective. Only eight patients with LVEF below 20% have undergone CABG in Japan. Thus, we reported our patient with some discussion on operative indication and perioperative management.

Aged↗
PubMed1994

[Cushing's syndrome due to huge bilateral adrenocortical multinodular hyperplasia--ACTH-independent bilateral adrenocortical macronodular hyperplasia(AIMAH)].

Six cases with ACTH-independent bilateral adrenocortical macronodular hyperplasia (AIMAH) were presented, and 21 reported cases were reviewed. Bilateral adrenal glands in AIMAH were greater than those in any other subtype of nodular hyperplasia. They were greater than 72 g in combined weight and were occupied by numerous yellow nodular/subnodular lesions. Histologically, hyperplastic lesions were composed of small compact, small clear, and usual clear cells. All of these three elements contained cells positive for PCNA but were negative for HLA-DR alpha. Small compact cells often showed positive staining for vimentin. Small cells showed underdeveloped organelles with rare nuclear grooving and were poor in lipochrome. The results are consistent with the view that AIMAH is primarily a nodular hyperplasia of the upper zona fasciculata and that it is a distinct subtype of Cushing's syndrome. Image analyses may play a major role on preoperative diagnosis of AIMAH. Bilateral adrenalectomy is the treatment of choice.

Adrenal Cortex↗
PubMed1994

Effects of cysteamine, a somatostatin depleter, on the renin-angiotensin-aldosterone axis and glomerulosa cell growth in rats.

Cysteamine, a specific somatostatin depleter, was given to male rats to clarify its role in relation to the renin-angiotensin-aldosterone (RAA) axis and glomerulosa cell growth. Rats received seven daily sc injections of cysteamine at doses of 50 or 150 mg/kg body weight (BW). Their adrenal weights and whole cortical thickness increased, but zona glomerulosa thickness decreased dose-responsively. Plasma renin activity (PRA) and aldosterone concentration (PAC) decreased. Similar results were observed in rats on a low or high salt diet and receiving daily doses of 150 mg/kg BW of cysteamine. In hypophysectomized rats, however, cysteamine given for seven days at daily doses of 100 mg/kg BW did not change either PRA or PAC. Adrenal weight did not change either too. Our results indicate that cysteamine suppresses the RAA axis and glomerulosa cell growth, probably through pituitary factors.

Animals↗