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Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 217 records · Page 12Linked to original sources
PubMed1988

A case of giant mediastinal leiomyoma with long-term survival.

A 67-year-old female was emergently admitted to our hospital because of severe dyspnea with cyanosis. One month before admission, she consulted a doctor and chest x-ray disclosed a huge tumor shadow occupying most of the left hemithorax. At that time, she did not complain of any particular symptoms except slight cough. Twelve days after admission, the patient lost consciousness and an emergency operation was performed. The tumor showed severe adhesion to the aorta and the lower lobe of the left lung, but not to the esophagus. After the operation, mechanical ventilation was necessary for 13 days to recover pulmonary function. Histological diagnosis was made as leiomyoma, which is rarely seen in the mediastinal region. At present, the patient survived 10 years without any symptom of recurrence. In this paper, the authors report a case of mediastinal leiomyoma which received an emergency operation and attained long term survival. Twelve similar cases reported in the past were also reviewed.

Aged↗
PubMed1988

Osteonecrosis of the femoral head of growing, spontaneously hypertensive rats.

The femoral head lesions of male spontaneously hypertensive rats (SHRs), which occur naturally and resemble Perthes' disease in man, were investigated radiographically and histologically. In the early phase of growth in SHRs, i.e., a period of 6 to 15 weeks after birth, the femur was shorter than that of control rats, and ossification in the epiphysis of the femoral head was considerably retarded. Osteonecrosis of the femoral head of SHRs appeared at the age of 9 weeks, and occurred in eight out of 12 femoral heads at 15 weeks. We suggest that osteonecrosis in the femoral head of SHRs is due to an abnormality of the cartilage in the epiphysis and metaphyseal growth plate and subsequent enchondral ossification.

Animals↗
PubMed1988

Median sternotomy with bilateral bullous resection for unilateral spontaneous pneumothorax, with special reference to operative indications.

Simultaneous bilateral pulmonary operations were done through median sternotomy in 29 patients with unilateral spontaneous pneumothorax, because bullae and blebs of the lung are frequently bilateral. Bullous lesions on the contralateral lung were encountered in eight of 10 patients (80%) in whom no roentgenographic evidence of the additional lesions had been detected preoperatively. Postoperative examination of percent vital capacity was satisfactory (more than 80%) in 21 of 23 patients followed up over a month after operation, and this suggested that simultaneous bilateral thoracotomy through median sternotomy does not lead to a much greater decrease in postoperative pulmonary function than does unilateral operation. To determine the indications for this method of treatment, we investigated the frequency of subsequent development of contralateral pneumothorax in 178 patients who initially had unilateral spontaneous pneumothorax. The occurrence rate of contralateral pneumothorax with visible bullae on chest roentgenograms was as high as 60% and 33.3% in patients in their teens and in those in their 20s, respectively. In conclusion, therefore, the bilateral operative approach should be considered, especially in teenaged patients with contralateral bullae, in whom the highest contralateral occurrence rate of 60% was found.

Adolescent↗
PubMed1987

Ventricular myocytes from neonatal rats are more responsive to dexamethasone than atrial myocytes in synthesis of atrial natriuretic peptide.

Using the primary culture of neonatal rat ventricular myocytes, synthesis and secretion of rat atrial natriuretic peptide (rANP) were studied. Ventricular myocytes in culture, although contained less amounts of cellular immunoreactive (IR)-rANP, secreted substantial amounts of IR-rANP at a rate comparable to that of atrial myocytes. Dexamethasone markedly stimulated synthesis and secretion of IR-rANP by cultured ventricular myocytes in a dose-dependent manner (10(-10)-10(-6) M), of which effect was far more potent than that in atrial myocytes. Testosterone and triiodothyronine also stimulated synthesis and secretion of ventricular IR-rANP to the extent comparable to that of atrial IR-rANP. The present study suggests that tissue-dependent difference in glucocorticoids sensitivity plays an important role in the regulation of developmental ANP gene expression in mammalian heart.

Age Factors↗
PubMed1987

Role of atrial natriuretic polypeptides for exaggerated natriuresis in essential hypertension.

Eighteen patients with essential hypertension were separated into 2 groups, renin-unresponsive and renin-responsive, on the basis of their plasma renin response when challenged by furosemide and upright posture. The response to acute infusion of hypertonic saline solution (1.4% saline solution at a rate of 0.3 ml/min/kg over 60 minutes) was then studied. In the renin-unresponsive group, peak rate of fractional excretion of sodium and peak urine flow after saline loading were 7.6 +/- 0.7% and 476 +/- 34 ml/hour, respectively, and peak value of atrial natriuretic polypeptides (ANP) was 784 +/- 140 pg/ml. In the renin-responsive group, the values were 3.1 +/- 0.4%, 194 +/- 29 ml/hour and 115 +/- 33 pg/ml. Both fractional excretion of sodium, urine flow and ANP response were significantly higher (p less than 0.01) in the renin-unresponsive group. Moreover, a highly significant relation (r = 0.82, p less than 0.01) was observed between fractional excretion of sodium and ANP levels in all hypertensive patients. The degree of saline-induced natriuresis was not related to blood pressure, heart rate, endogenous creatinine clearance, antidiuretic hormone or preexisting level of aldosterone. Plasma renin activity changed little in either group during saline infusion, but tended to be higher at all times in the renin-responsive patients. The present findings suggest that the enhanced secretion of ANP is an important determinant for exaggerated natriuresis observed in patients with renin-unresponsive hypertension.

Adult↗
PubMed1987

Effects of steroid and thyroid hormones on synthesis of atrial natriuretic peptide by cultured atrial myocytes of rat.

The in vitro effects of various steroid and thyroid hormones on synthesis of rat atrial natriuretic peptide (rANP) were studied using new-born rat atrial myocytes in culture. Dexamethasone, testosterone and triiodothyronine markedly stimulated both synthesis and secretion of immunoreactive (IR)-rANP with the same peak after 4-day-culture. Dexamethasone and testosterone dose-dependently (10(-7)-10(-6) M) stimulated synthesis of IR-rANP and were the most potent among various steroids tested. Triiodothyronine (T3) also stimulated synthesis of IR-rANP in a dose-dependent manner (10(-8)-10(-7) M), of which effect was more potent than that of tetraiodothyronine, whereas reverse T3 was ineffective. The present study clearly shows that glucocorticoids, androgens and thyroid hormones directly stimulate synthesis of ANP by atrial myocytes and suggests that ANP may play a potential role in mediating and/or modulating the biological effects by these hormones in the cardiovascular system.

Adrenal Cortex Hormones↗
PubMed1987

The role of atrial pressure in secreting atrial natriuretic polypeptides.

The role of atrial pressure and catecholamines in secreting human atrial natriuretic polypeptides (hANP) were investigated in patients with acute or old myocardial infarction (AMI or OMI). No differences were observed in hANP levels obtained from brachial vein, right atrium, pulmonary artery and femoral artery, suggesting that hANP degradation in the pulmonary circulation has little clinical significance in hANP measurement. Plasma hANP levels in 10 patients with AMI were higher than those in controls and significantly correlated to both mean right atrial pressure (mRA) and pulmonary wedge pressure (PCW) (r = 0.76, p less than 0.05; r = 0.95; p less than 0.01, respectively). In 12 patients with OMI, plasma hANP levels were normal at rest and were significantly increased (p less than 0.01) with bicycle ergometer exercise associated with significant elevations of plasma catecholamine levels, mRA, and PCW. However, the increments of hANP correlated only to those of PCW. These results suggest that the elevation of atrial (principally left atrial) pressure rather than catecholamine stimulates hANP secretion.

Aged↗
PubMed1987

CA 125 antigen is an effective diagnostic for external endometriosis.

We measured serum levels of CA 125 in 26 patients with external endometriosis, using CA 125 RIA Kits. The normal range was instituted below 39 U/ml. The mean CA 125 level (+/- SD) was 55.1 +/- 24.9 U/ml in patients with external endometriosis, the positive rate being 71.4%. Considering the clinical stage of external endometriosis, the mean CA 125 level and positive rate increased to 64.5 +/- 23.2 U/ml and 93.3%, respectively. The CA 125 levels in these patients gradually decreased after surgery and/or Danazol treatment and the levels were below 39 U/ml within four weeks. Thus, progressive external endometriosis can be accurately diagnosed by determining the serum levels of CA 125, and appropriate clinical treatment designed.

Adult↗