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Biomedical subjects

N Yamate

Publications and source records attributed to N Yamate.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Emergency myectomy in a patient with hypertrophic obstructive cardiomyopathy complicated with left heart failure and cardiac arrest].

Major cause of death in HOCM is sudden death due to ventricular arrhythmias, and only 10% of the death is caused by congestive heart failure. We report a 38-year-old woman of HOCM complicated with lung edema and cardiac arrest due to acute left heart failure. Intraventricular pressure gradient showed 125 mmHg in previous study, and echocardiogram demonstrated evidences suggestive of terminal-staged HOCM. After unsuccessful attempts of intravenous propranolol administration, emergency myectomy of left ventricular outflow tract was carried out. Postoperative course was uneventful, and intraventricular pressure gradient was relieved. The patient is now asymptomatic without medication after 1 years of operation. This case suggests that emergency myectomy may be a choice to relieve refractory congestive heart failure in patient with HOCM.

Adult↗
PubMed1995

Demonstration of apoptosis in neuroblastoma and its relationship to tumour regression.

The in vivo occurrence of apoptosis in neuroblastomas was investigated. Histologically, a number of tumour cells showed typical apoptotic changes, including cell shrinkage, condensed and fragmented nuclei, eosinophilic cytoplasm, and absence of the inflammatory response. These cells coincided closely with the so-called karyorrhectic cells. An electrophoretic DNA ladder, a functional hallmark of apoptosis, was demonstrated in four of six tumours, and DNA fragmentation was detected in situ by terminal deoxytransferase-mediated nick end-labelling in 26 of 35 tumour specimens (74%). The labelled cell counts ranged from 5 to 62 per 5000 tumour cells (mean +/- SD: 15.0 +/- 14.5). Immunoperoxidase staining revealed that an apoptosis-suppressing protein, bcl-2, was expressed abundantly in advanced-stage tumours, whereas it was absent from karyorrhectic-apoptotic cells. Several tumours with the potential for spontaneous regression were bcl-2-deficient. Immunostaining of the Fas receptor for apoptosis demonstrated that the tumour cells expressed this molecule on their cell surfaces. Our results provide evidence of apoptosis in neuroblastomas and suggest that bcl-2 and the Fas receptor may play a role in its regulatory mechanisms.

Adolescent↗
PubMed1995

Doppler ultrasonographic evaluation of hepatic circulation in patients following Kasai's operation for biliary atresia.

The hepatic circulation of eight children who underwent Kasai's operation for biliary atresia was serially evaluated by Doppler ultrasonography (US). A total of 36 examinations were performed to evaluate the maximal velocities (mvs) of the main portal vein (MPV), splenic vein (SV), and hepatic artery (HA), and to analyze the spectral waveform and the directions of flow. The mean mvs-MPV in four patients for whom adequate biliary diversion had been achieved and whose serum bilirubin had fallen to within the normal range (group A), was 19.8 +/- 7.5 cm/s. Their MPV waveforms were constant, with blood flowing toward the liver, while their mean mvs-SV was 12.1 +/- 5.8 cm/s. In two other patients with apparent hypersplenism, but whose serum bilirubin levels had fallen to nearly normal (group B), the mean mvs-MPV was 20.7 +/- 10.4 cm/s and the mvs-SV was 22.4 +/- 10.4 cm/s. In contrast, the mvs-MPV in the two remaining patients, whose serum bilirubin levels had either not fallen to within the normal range, or had fallen initially but increased due to recurrent cholangitis (group C), was 14.2 +/- 9.1 cm/s. In these patients, the waveforms were unstable, the MPV flows were occasionally hepatofugal, and their mean mvs-SV was 18.0 +/- 5.8 cm/s. The mvs-HA were markedly increased in the latter four patients, whose clinical condition had also deteriorated. These observations led to the conclusion that hepatic circulation evaluated by serial Doppler US provides important information about liver status in children who have undergone Kasai's operation for biliary atresia.

Adolescent↗
PubMed1995

Unilateral pulmonary agenesis with tracheoesophageal fistula: a case report.

The authors describe a neonate with unilateral pulmonary agenesis and esophageal atresia (Gross type C). Definitive repair for the atresia was completed during the early neonatal period, and the patient is alive and well more than 1 year after surgery. Most patients with pulmonary agenesis associated with esophageal atresia have not survived, mainly because of postoperative cardiorespiratory failure. Early protection and preservation of respiratory units is essential for the management of these patients.

Esophageal Atresia↗
PubMed1995

Bilateral intralobar pulmonary sequestration.

A 34-year-old male presented with an infected intralobar pulmonary sequestration of the left lower lobe. Aortography revealed bilateral anomalous systemic arteries, originating in the lower level of the descending thoracic aorta, to the lower lobe on each side. The portion of the right lower lobe, which was perfused by the anomalous systemic artery was seen otherwise normal in anatomy without any recognizable sequestered lung tissue. The patient underwent a left postero-lateral thoracotomy on June 22, 1994. Each aberrant artery was recognized to take off from a common branch of the descending aorta at the level of the diaphragm. A left lower lobectomy with division of the left aberrant artery as well as ligation of the right anomalous artery were done. A postoperative pulmonary perfusion scan depicted normal uptake of radioactivity in the right lower lobe, suggesting normal pulmonary arterial perfusion to the area receiving previously the anomalous systemic arterial flow. An anomalous systemic artery perfusing an otherwise normal lung can be classified as one of the forms of intralobar pulmonary sequestration and could be ligated without resection of the involved area of the lung.

Adult↗
PubMed1995

[Surgical treatment of posterior mediastinal teratoma].

A 22-year-old male patient was admitted to our hospital because of an abnormal shadow on a chest X-ray taken for routine examination. Preoperative diagnostic work up including chest computed tomography and magnetic resonance imaging suggested that the tumor would most likely to be a posterior mediastinal lipoma. Through a right thoracotomy the tumor was removed successfully. Histologically it proved to be a mature teratoma. The incidence, etiology and diagnostic procedure of the mediastinal teratoma was discussed.

Adult↗
PubMed1994

Characterization of platelet activity in neuroblastoma.

A study was conducted to characterize the platelet aggregation induced by neuroblastoma tissue to investigate the mechanism of hypercoagulability in patients with neuroblastoma. The patients whose tumor tissues were examined had been shown clinically to have enhanced platelet activity. Platelet aggregation induced by neuroblastoma tissue extract was compared with that of other pediatric tumors. The effects of pretreatment with an antithrombin agent and prostacyclin (PGI2) on the platelet aggregation induced by tumor tissue extracts were also evaluated. Tissue extracts of 12 of 15 neuroblastomas, 3 of 3 Wilms' tumors, and 1 pheochromocytoma were demonstrated to have an activity that potentiated platelet aggregation in vitro. The platelet aggregation induced by tissue extracts of neuroblastomas and other tumor tissues was suppressed almost completely by pretreatment with a PGI2 analogue. The aggregation induced by neuroblastomas and the pheochromocytoma was also suppressed by pretreatment with an antithrombin agent, argatroban, whereas the aggregation induced by Wilms' tumors was not suppressed by this agent. These results suggest that (1) malignant tumors in children also have some chemical substances that sensitize platelet activity, such as those in adult cancers, and (2) thrombin is one of the mediators stimulating platelet aggregation in cases of neuroblastoma, although it is unlikely to be a contributing factor in other pediatric malignancies such as Wilms' tumor.

Antithrombins↗
PubMed1994

The first step of experimental study on hybrid trachea: use of cultured fibroblasts with artificial matrix.

Anastomotic stenosis secondary to developing granulation tissue prevents an artificial trachea of non-porous type model from a safe practical use. Taira reported that a non-porous artificial trachea having soft ends for anastomosis works better in this regards apparently by cushioning mechanical stimulations repeatedly applied to the anastomotic rings than most models ever studied have done. We hypothesized that hybridization of soft anastomotic ends of nonporous artificial trachea may further prevent granulation tissue at the anastomoses hopefully by leading epithelial growth earlier onto the inner surface of graft's ends. The graft of our use was made of a 5-cm-long knitted dacron tube with inner coating with silicone rubber covering the entire length but for a 5 mm segment at each end. To date six mongrel dogs have been subjected to test this hypothesis. A piece of subcutaneous tissue was obtained from each dog and prepared for culture of fibroblasts in MEM. These fibroblasts were then suspended in 0.1% collagen with MEM in a container, in which a graft was placed for further culture. Following some 3 weeks of this preparation each graft was implanted to replace a 10-cartilage-ring-long defect of the mediastinal trachea of each donor dog. One dog is enjoying active life 11 months postop, and another 3 months. Four dogs died from anastomotic stenosis 2 to 3 months. Being encouraged by the fact that the anastomotic rings of the long term survivors show bronchoscopically patency more than 40% of cut surface area, and some portion with possible epithelialization without granulation, we will report our further results, along with histological study.

Animals↗
PubMed1994

[Coronary artery bypass grafting for a patient with single coronary artery].

A 47-year-old man was admitted with suddenly developed chest pain. Coronary arteriography could not identify the right coronary orifice at the right coronary sinus. Left coronary arteriography revealed that the right coronary artery originated from a proximal segment of the left anterior descending artery with subtotal obstruction at the segment just distal to the bifurcation of the right and anterior descending arteries. Coronary artery bypass grafting to the middle segment of the left anterior descending artery was carried out with satisfactory result. To our knowledge, only seven cases with a diagnosis of single coronary artery who underwent coronary artery bypass grafting have been reported.

Coronary Angiography↗
PubMed1993

Hemangioma of the upper arm associated with massive hemorrhage in a neonate.

A rare case of an ulcerated hemangioma of the upper arm in a neonate is described herein. Resection of the huge hemangioma, which occupied the axilla and extended down the entire length of the upper arm, was necessary due to massive hemorrhage from the ulcer and progressive heart failure caused by the arteriovenous fistula in the hemangioma. After complete resection of the hemangioma, extensive defects of the skin and subcutaneous tissue were replaced by a skin flap closure technique which involved considerable difficulty. However, the arm gradually recovered its size and function with good wound healing. The present case illustrates that rapid surgical intervention may be required to prevent clinical deterioration in such cases.

Arm↗
PubMed1993

An infant with bilateral adrenal neuroblastoma found by mass-screening: report of a case.

A male infant with bilateral adrenal neuroblastoma found by mass-screening is herein reported. The patient presented with almost equal-sized tumors, each remaining confined to the respective adrenal gland without crossing the midline. No other tumorous lesion was evident. The two adrenal tumors had similar histologic features and appeared to have grown concurrently. Such simultaneous occurrence of primary adrenal neuroblastoma is unusual, and appears to reflect the multicentric origin of this tumor.

Adrenal Gland Neoplasms↗
PubMed1993

Expressions of N-myc and ras oncogene products in neuroblastoma and their correlations with prognosis.

Thirty-six neuroblastomas were studied to determine the clinical significance of the N-myc gene product, N-myc, and the ras gene product, p21. The expressions of both gene products were analyzed immunohistochemically using formalin-fixed paraffin sections. Neuroblastoma cells were positive for N-myc expression in 13 cases and for p21 expression in 19 cases. N-myc expressions showed no significant relation to any clinical prognostic factor, whereas p21 expression was well correlated with clinical staging and Shimada's classification. There was a tendency for p21 expression to be low in N-myc(+) tumors, whereas p21 expression was frequently detected when N-myc expression was absent. The survival rate for N-myc(-) patients was significantly higher than for N-myc(+) patients (P < 0.01). The survival rate for p21(+) patients was significantly higher than for p21(-) patients (P < 0.001). In addition, N-myc(+) and p21(-) patients showed a strong tendency towards a poor prognosis, whereas a combination of p21(+) and N-myc(-) indicated a good prognosis (P < 0.01). The results suggest that expressions of N-myc and p21 detected by immunohistochemical staining could be among the most reliable prognostic indicators in neuroblastoma patients.

Adolescent↗
PubMed1993

[Surgical treatment of type A aortic dissection combined with aortic root lesions].

From January 1980 to December 1992, 36 patients with type A aortic dissection were operated on at the St. Marianna University Hospital. Hospital mortality and 10-year survival rate in 26 patients (Group I and II) undergoing replacement of the ascending aorta with or without hemi-arch resection (including one case of aortic wrapping for the closing dissection) were 19.2% and 88.0%, respectively. Among the patients having aortic root destructions due to acute aortic dissection or preexisting annuloaortic ectasia (Group III), 8 patients underwent aortic root reconstruction with a valved conduit and 2 patients supra-coronary aortic resection and graft replacement with concomitant coronary artery bypass grafting with 20.0% of hospital mortality and 55.6% of 10-year cumulative survival rate. Modified Bentall operation using Carrel patch method seems to be preferable to avoid postoperative complications for the case with intimal tear extending to the aortic sinuses, ruptured outer layer of the aortic root or preexisting AAE. If the disrupted coronary artery is concerned, coronary artery bypass grafting is mandatory. In the case of replacement of the ascending aorta for the dissection extending to the aortic sinuses, complete obliteration of the proximal false lumen must be required to avoid uncontrollable bleeding and compromised coronary blood flow.

Adult↗
PubMed1992

[Two cases of the brachiocephalic artery avulsion due to blunt chest trauma].

Two young adult patients with brachiocephalic avulsion due to blunt trauma are reported. Both of them were brought to the emergency room of St. Marianna University Hospital with the blunt chest trauma and lung contusion due to the traffic accident. A widening of the superior mediastinum and mediastinal hematoma surrounding the major branches of the aortic arch were demonstrated on chest roentgenogram and contrast enhanced CT scan, however, these evidences were not valuable for the diagnosis. Aortogram revealed an aneurysmal dilatation at the origin of the brachiocephalic artery in the first case and at its distal portion in the second case. Emergency operation was performed under the simple cross clamp of the brachiocephalic artery without any adjunct means. In the first case, 10 mm knitted Dacron graft was interposed between the ascending aorta and distal segment of the brachiocephalic artery. In the second case, the brachiocephalic artery was replaced with 10 mm knitted Dacron graft. The postoperative course was uneventful and no neurological deficit was noted in these cases.

Adolescent↗
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↗